STATE OF THE ENVIRONMENT

1996 REPORT

list of appendices

Page No.

Appendix Ι Sources and Levels of Aquatic Pollution

Ι - i

Table Ι - B: Physical and Biological Ranges

Ι - ii

Table Ι - C: Physicochemical Ranges

Ι - iii

Table Ι - D: Functional and Non-Functional Sewage Treatment Plants in Trinidad and Tobago

Ι - iv

Appendix Ι Ι Air and Noise Pollution Ι Ι - i

ACKNOWLEDGMENT

This second State of the Environment report has been written and edited by the following team: Carol James, Julian Kenny, Winston Rudder, Marva Salvador-Arthur and Dorothy Sookdeo. The report is based on a series of studies commissioned by the Environmental Management Authority as part of its Environmental Data and Information Project.

The Environmental Management Authority (EMA) wishes to thank these persons for volunteering their time and expertise to this project. The Authority is also very grateful to the personnel from those ministries, statutory bodies and institutions who assisted in reviewing the studies done for this report and to its own staff who worked tirelessly at communicating with agencies and individuals, preparation of the text and illustrations, data collection and final editing of the document.

1.0 Introduction

Environmental degradation in Trinidad and Tobago has historical roots that are not too dissimilar from those in the rest of the world attributed largely to economic growth and development and growth of human population. Between the islands themselves, different patterns of development have resulted in differencies in environmental degradation, for whereas in Trinidad the main thrust has been heavy industrial development, in Tobago it has been tourism development. Generally, the country passed through a long period of agricultural development, typical of the region, moving into exploitation of petroleum resources and later heavy industrialization. Trinidad and Tobago experiences much of the full range of environmental problems, from widespread pollution of its waterways and nearshore waters to air pollution, chemical spills, illegal dumping, deforestation, fisheries and wildlife depletion.

Many of the laws of the country date back to the early part of the century, being amended from time to time to adjust to change in circumstances. Thus, for example, laws for the conservation and management of fisheries and forests, remain substantially the same from colonial times, although there have been occasional amendments. The past few years have seen progressive change in many of the laws and some, closely related to management of different aspects of the environment are before the public for comment. These are the bills on: Establishment of a National Parks and Wildlife Authority, Occupational Health and Safety, and Planning and Development of Land.

Institutional arrangements for environmental management in the first half of the century were through various departments established specifically to address a range of sectoral issues. Departments gave way to Ministries on the advent of party government and political independence. Such separate entities were not streamlined to address the considerable overlap of functions, in enforcement of legislation, scientific research and monitoring, and assignment of priority. There have also been important gaps which were not being addressed by any agency. Such institutional fragmentation and instability in administrative oversight in the past three decades has apparently now stabilized with the Environmental Management Authority (EMA) assuming overall responsibility for environment and line ministries being assigned specific roles. The Ministry of Energy and Energy Industries, for example, sets terms and conditions for investors in the energy sector, while the Ministry of Agriculture, Land and Marine Resources is responsible for management of renewable resources.

One of the major problems encountered in management of the environment is that of co-ordination of activity. Until 1995 this was entirely the responsibility of the line ministry which could set its own priorities. With several different Ministries and Agencies responsible for over 70 diverse pieces of legislation, it was inevitable that there would be little coordination of effort. In 1995, Parliament enacted the Environmental Management Act which established a parastatal

authority, the Environmental Management Authority, to undertake three major functions, namely co-ordination of effort amongst the various institutions with responsibility for the environment, management of the widespread pollution problem and promotion of public awareness of environmental concerns. The Act places the responsibility for preparation of environmental standards for air, noise, water and solid waste pollution, and toxic and hazardous substances on the Authority. Enforcement is through the Authority and environmental inspectors drawn from amongst different agencies with which the Authority has entered a Memorandum of Understanding. The Act also requires the establishment of an Environmental Commission with wide punitive powers.

In addition to attention to immediate and local environmental management problems, Trinidad and Tobago also has responsibilities regionally and internationally. It has acceded to treaties on ozone depleting substances, biological diversity, climate change, trade in endangered species, conservation of wetlands of global importance, conservation of the marine areas of the Wider Caribbean Region and trade in hazardous substances. Some of these treaties require domestic legislation for effective implementation of the terms of the treaties. The Convention on International Trade in Endangered Species of Flora and Fauna (CITES), for example, which Trinidad and Tobago acceded to in 1984, requires special domestic legislation which is yet to be drafted and implementation is still piecemeal and ad hoc.

The Environmental Management Act of 1995 requires, among other things, an annual State of the Environment Report to be submitted to Parliament. The first State of the Environment Report was prepared for submission to Parliament by April 30th. 1996, barely four months after the first appointments of staff were made, and was based on material supplied by different agencies with responsibility for environmental matters.

As mandated by law, the State of the Environment Report is intended to serve three main objectives:-

• to provide a foundation for improved decision-making at all levels; • to increase awareness and understanding of environmental trends and

conditions; and • to facilitate the measurement of progress on the pace and direction toward

enhancing or mitigating observed conditions and trends.

This first State of the Environment report dealt with six focal areas all of which have been utilized in this second report. There has been some upgrading of the content based upon information from a series of special studies commissioned by the Authority and listed in the Bibliography at the end of the reports. One of the focal areas, "Air and Noise" which has hitherto received comparatively slight attention, is given special emphasis in this report. Also utilized were earlier

reports on the environment prepared by the former Ministry of the Environment and National Service.

In this report the editors have deliberately omitted text and footnote references for ease of reading. Special appendices covering particular topics are included. Appendix Ι provides detailed information on sources and levels of aquatic pollution. Appendix Ι Ι addresses some aspects of air and noise pollution with greater depth.

The final chapter synthesizes in one place and text major issues emerging from the special studies commissioned by the Authority and serves to facilitate the process of ordering priorities.

2.0 GENERAL CHARACTERISTICS - TRINIDAD AND TOBAGO

2.1 Introduction

The Republic of Trinidad and Tobago is an archipelagic state which, by law, includes:-

(i) The islands of Trinidad and Tobago comprising a total land area of 5,123 square kilometres;

(ii) Smaller islands including Little Tobago and St. Giles off the north-east coast of Tobago; the Five Islands and islands of the Dragon's Mouth (of which Gasparee, Monos, Huevos and Chacachacare are the main ones) which lie between the Chaguaramas Peninsula and the Peninsula de Paria in Venezuela and Soldado Rock in the Serpent’s Mouth between Icacos and Pedernales; and

(iii) Various marine areas over which the State is sovereign or claims sovereign rights, comprising a total sea area of some 75,000 square kilometres approximately 15 times the land area. These areas are delimited from Venezuela, Grenada and Barbados in accordance with Law of the Sea principles.

2.2 Location

Trinidad and Tobago is located at the southern end of the Caribbean island chain, between 10 degrees and 11 degrees 30 minutes North latitude and 60 degrees 30 minutes and 62 degrees West longitude. Both islands are situated on the continental shelf of South America, from which they became separated in geologically recent times; approximately 11,000 years ago in the case of Tobago and 1,500 years ago in the case of Trinidad. Trinidad is separated from Venezuela at its nearest points on the northwestern and southwestern peninsulas by distances of about 13 km, and from Tobago by a distance of 32 km. Owing to its location the country is less exposed to tropical storms and hurricanes, its marine ecosystems are much influenced by Orinoco discharge while its terrestrial biota is largely South American. Map 2-1 illustrates Trinidad and Tobago’s location.

2.3 Climate

The islands have a tropical wet climate of the monsoonal type, influenced in the main by latitude, oceans, size of landmass and topography. Rainfall and temperature records show fair variation in the long term and occasionally there have been periods of drought and elevated temperatures.

2.3.1 Rainfall

Rainfall is seasonal with a wet season from June to November and a dry season from December to May. In most years there is a short dry spell, the petit careme, during September and October. Approximately two thirds of all precipitation is recorded in the rainy season. In Trinidad average annual rainfall is 2,200 mm but there is, depending on location and topography, wide variation between 3,500mm in the eastern Northern Range and 1,300 mm on the off-shore islands of the north west peninsula and in the southwest peninsula of Trinidad. The pattern for Tobago is comparable with that of Trinidad in amount, seasonality and spatial distribution. During the wet season there is a progression of tropical waves moving to the west from Africa's West Coast through lower middle Atlantic latitudes. Some of these develop into depressions, storms and hurricanes, but the islands are situated at the southern boundary of the main tracks of these phenomena. Trinidad was struck by a mild hurricane or severe tropical storm in 1933 affecting the southern part of the island. Within more recent years it experienced tropical storm Alma in 1974, while Tobago was seriously damaged by hurricane Flora in 1963.

2.3.2 Temperature

The average temperature ranges from 25 degrees Celsius [C] in January the coolest month, to 27.2 degrees C in May, the hottest month. Diurnal variations in temperature, which average 7.3

degrees C between night and day exceed these seasonal variations in mean temperature.

2.3.3 Relative Humidity

Average relative humidity is approximately 80% but ranges between 50% in the dry season and 100% in the rainy season. During the dry season there is wide diurnal fluctuation in relative humidity. The coincidence of high humidities and reduced wind velocities in the rainy season adversely affects the level of human comfort enjoyed at that time.

2.3.4 Winds

The Easterly Trades dominate the wind regime, showing great steadiness throughout the year. The average wind speed ranges from 20 to 28 km/hr, with lowest speeds in the rainy season. There is considerable local variation in wind directions, related to a range of factors including topography, the diurnal cycle and thunderstorm activity.

2.4 Physiography

TRINIDAD:

In Trinidad five (5) main physiographic regions exist which reflect the geological structure of the island. These are the Northern Range, the Northern Basin, Central Range, Southern Basin and Southern Range as illustrated in Map 2-2.

2.4.1 The Northern Range

The average elevation of the Northern Range - the eastern-most extension of the Andean mountain system of South America is about 700m with two dominant peaks at El Cerro del Aripo (940m) and El Tucuche (936m). The main divide separates a longer incline on the southern side, from the land on the northern side which falls steeply towards the Caribbean Sea (Map 2-2), there being an almost sheer fall of over 150m from cliff to sea in several places. The Range is a complex of strongly folded metamorphic rocks of the Cretaceous period. Over 80% of its slopes have a gradient in excess of 20 degrees, with a substantial proportion of slopes

greater than 30 degrees. The Northern Range is a major current and potential catchment for potable and industrial water in Trinidad as several rivers and streams emanate from it, some flowing north to the Caribbean Sea, others flowing south through the Northern Basin to the Gulf of Paria and the Atlantic Ocean.

2.4.2 The Northern Basin

The Northern Basin extends from the foothills of the Northern Range to those of the Central Range and consists of flood plains and alluvial flats, terraces and the Las Lomas peneplain. Elevations generally vary between 15 to 70 metres with the flood plains and flats lying mainly below 10m. This Northern Basin consists of rolling land dissected by many streams. Rounded hills capped with hill-top sands and gravels are exploited for economic purposes. The northern boundary of this basin is the El Pilar fault system, an active zone running from east to west.

2.4.3 The Central Range

The Central Range is an irregular ridge running diagonally southwest to northeast across the island from Pointe-a-Pierre to Manzanilla Point. It is about 55 kilometres long and between 8 and 15 kilometres wide, consisting mainly of ridges of rugged limestone. The highest point is Mount Tamana (330m) near the eastern end of the Range. Slopes are mostly mild except on the southern end of the limestone peaks which are steep, up to 30 degrees. The rivers that arise on the flanks of this range play significant roles in potable water supply or drain into major wetland areas.

2.4.4 The Southern Basin

The Southern Basin or Naparima Peneplain differs from the Northern Basin mainly in altitude which ranges from sea level to 260 metres at San Fernando Hill. For the most part this basin is gently rolling and dissected by numerous small streams which dry up soon after the rains. The main drainage routes are the Poole-Ortoire, Guaracara and Oropouche rivers.

2.4.5 The Southern Range

The Southern Range has its highest point in the Trinity Hills at 325 m. From this point the range terminates almost abruptly on the east in the low area of Guayaguayare. In the western part of the range, west of Moruga, it splits into two, and diminishes towards the Cedros Peninsula. Drainage is by the Pilote River to the east, the Moriquite-Moruga River in the central area of the range and the Erin River to the west.

TOBAGO:

In Tobago there are two main physiographic units, the Main Ridge and the southwestern lowlands (Map 2-2).

2.4.6 The Main Ridge

The Main Ridge is a highland area running from northeast to southwest and rises to between 600 and 650 m. Like the Northern Range it is asymmetrical in cross profile resulting in a more gentle windward slope than its leeward face. Several steeply inclined rivers flow directly northwestwards from the highland to the leeward coast. The windward drainage pattern is dominated by longer less steeply inclined rivers e.g. the Richmond, Goldsborough and Hillsborough. The Courland River basin has a well developed system of tributaries which drains it. Stream flow in Tobago has declined substantially over the years as a consequence of deforestation.

2.4.7 The Southwestern Lowlands

These comprise a small coastal plain of coral terraces terminating in the fringing reef at Buccoo. The southwestern lowlands have been heavily perturbed during the past two centuries of human settlement.

2.5 Other Features

2.5.1 Wetlands

The larger wetlands are located in Trinidad, the three main ones being Caroni in the west, the Nariva in the east and the North Oropouche in the northeast. Less extensive wetlands occur in the southwest of Trinidad at Los Blanquizales, Rousillac, Icacos and South Oropouche. Wetlands contribute significantly to the rich biodiversity of both islands, particularly as habitat for resident and migratory fauna.

The Caroni Swamp adjacent to the Gulf of Paria measures about 3,300 hectares consisting of marine, estuarine and river alluvial deposits. It is mainly tidal and brackish but occasionally during the dry season excessive evaporation may lead to hypersaline conditions. It supports one of the largest mangrove forests in the insular Caribbean.

The Nariva Swamp measures about 6,000 hectares and it is one of the largest freshwater herbaceous swamps in the Caribbean and is of significance as a wetland of international importance under the Ramsar Convention. It is a shallow freshwater lagoon of which about 63% is under water during the wet season and is separated from the sea by a 26 kilometres long sand bar, the Cocal. The lagoon water is provided by numerous east-flowing rivers from the Central Range, the main ones being Navet, Biche and Nariva. The higher and drier inland areas to the west are undulating.

The North Oropouche Swamp occupies a smaller area at the mouth of the North Oropouche River. Previously it extended westward to include the Sangre Grande Basin but this was gradually filled in and covered over by river deposits derived from rocks originating from both the Northern and Central Ranges.

The two wetland areas of significance in Tobago lie on the southern coast at Bon Accord where it fringes the Bon Accord Lagoon and at a smaller area in Kilgwyn, the latter much diminished by airport construction.

2.5.2 Savannahs

Trinidad has a number of savannahs. Most lie in the northern basin but there are others at Erin and St. Joseph. Savannahs at Piarco, Mausica and O’meara have been much perturbed and largely converted to built facilities such as airports, industrial estates and low cost housing. Attempts have been made at reforestation of both Erin and St. Joseph savannahs using Caribbean pine. The last remaining savannah is the Aripo savannah, comprising several sub-units, some of which are under pressure from sand mining. The

peculiar physical characteristics of the Aripo savannah support an unusual flora including insectivorous plants.

2.5.3 The Coastline

The coastline of Trinidad is extremely varied and its form is much influenced by prevailing wave and current regimes. Erosion problems are severe where energy levels are high and sediments unconsolidated. The south coast is being severely eroded through the influence of wave action and the westward flowing currents in the Columbus Channel. Local differences in geology contribute to coastal form, with resistant strata forming headlands of many bays. Most beaches are relatively stable except at river mouths. Tobago's coastline is indented, forming many bays with inner beaches. Much of the sand of these beaches is of biological origin, especially in the south west.

2.5.4 Other Land Forms.

Numerous caves such as the Aripo, Oropouche, Tamana and Gasparee in Trinidad, waterfalls such as Blue Basin, Maracas and Paria in Trinidad and King’s Bay in Tobago, and river gorges such as Guanapo and Madamas in Trinidad all contribute to the diversity of physical features in Trinidad and Tobago.

3.0 SOCIO-ECONOMICS

3.1 Introduction

The impact of human activity on the environment is significantly influenced by the demographic characteristics of the population e.g., its size and growth rate, distribution and density, age structure and composition, education and occupational structure, health status and income distribution. These may be particularly acute in small islands such as Trinidad and Tobago where the urban population density is high. These characteristics in turn are reflected in the settlement, consumption and production patterns of a population with direct implications for waste generation and disposal, natural resource depletion and contamination of the environment.

Trinidad and Tobago is now approaching the mature stage of the demographic cycle with the population growth rate declining (Figure 3-1).

FIGURE 3:1: TRENDS IN POPULATION GROWTH, 1876-1995

This is in contrast to the past four and a half decades in which a declining mortality rate, a high fertility rate and an expanding population base, resulted in a population size which has rapidly increased and placed attendant pressure on the narrow natural

resource base. Furthermore, the country displays environmental problems of both the industrialized world and developing countries.

Rapid urbanization, the proliferation of spontaneous settlements, relatively high unemployment, inadequate land management, and overburdened, underdeveloped physical infrastructure and institutional support systems have emerged as serious issues having significant adverse environmental impacts.

Personal and household consumption patterns and levels also exert pressure on the environment. This is manifest in the burgeoning solid waste problem resulting from, not only the quantity of waste generated, but also the constituent materials, the latter having shown an increase in non-biodegradable components such as aluminum cans and plastic packaging over the last decade.

The economy is based primarily on petroleum, petrochemical production and processing and on manufacturing. Since environmental monitoring and management systems are embryonic, emission and effluent standards not fully developed and legislation inadequate or not enforced, pollutants from these industries have become pervasive and are threats to public health. Agriculture, forestry and fisheries together contribute modestly to Gross Domestic Product (GDP), but have significant impacts on the environment. Tourism, though a relatively underdeveloped sector, is being targeted for expansion and it is imperative that proper environmental guidelines and safeguards be put in place as this sector develops.

3.2 Demographic and Socio-Economic Characteristics

There have been significant changes in the demographic characteristics of the population of Trinidad and Tobago over the years, resulting in evident alterations to the biophysical environment, particularly in areas of high population density. In this context the following current demographic characteristics and trends will be considered:

(i) population and population growth

(ii) structure and composition

(iii) density and distribution, and

(iv) education and health.

3.2.1 Population and Population Growth

The population of Trinidad and Tobago was estimated at 1,269,000 in 1996, with 50.4% male and 49.6% female. Family planning programmes, the availability of birth control measures, efforts to limit family size and the increase in the numbers of women seeking higher levels of education and pursuing careers have been responsible for a slight decrease in fertility rates and therefore also of the population growth rate over the last twenty years (Figure 3-1). Despite this decrease in population growth rate, the population size has rapidly increased. Population projections indicate that at a growth rate of 1.2% the population is expected to grow to 1.78 million by 2025. This represents an addition of about 15,500 persons to the population annually (Figure 3-2).

3.2.2 Structure and Composition

In 1996, approximately 29% of the population was under the age of 15 years. The age groups, ‘15 to 24 years’, ‘25 to 64 years’ and ‘65 years and over’ accounted for 18.3%, 46.5% and 6.2% of the population respectively Figure 3-3 compares the 1990 trend with a projection to 2025. Population structure and composition have been greatly shaped by trends in fertility rates and life expectancy. With the continued decline in fertility rates and longer life expectancy it is anticipated that the proportion of the population under the age of 24 years will decrease.

FIGURE 3-3

The population is comprised mainly of two ethnic groups. Persons of African and East Indian descent each account for approximately 40% of the total population.

3.2.3 Distribution and Density

In 1990, the population density of Trinidad and Tobago was 237 persons per square kilometres. The population is concentrated in urban areas in north west Trinidad and in San Fernando and

approximately 90% of the population live along the west coastal area and the foothills of the Northern Range. Population densities are greatest in the urban centres of Port of Spain (4,601 persons per square kilometres), as indicated in Map 3-1. San Fernando (3,572 persons per square kilometres) and Arima (2,861 persons per square kilometres). Between the 1960’s and 1990’s there was a noticeable migration from these urban areas to the suburban areas such as Diego Martin, St. Ann's and Tacarigua. Approximately 36% of the total population resides along the East-West Corridor and other areas of former County St. George. In addition, population has been increasing in Chaguanas at a significant rate since the mid 1970’s. Most of the population of Tobago is concentrated in the southwest part of the island.

3.2.4 Education and Health

Between 1970 and 1990, there was a steady but significant increase in the educational attainment levels of the population. This was demonstrated by the decline in the proportion of persons whose highest level of educational attainment was at the primary level and an increase in the percentage of those at the secondary and tertiary levels. During the period, women in particular, made marked progress especially at the tertiary level, where their enrollment at the University of the West Indies exceeds that of men.

With regard to health indicators life expectancy has increased. Infant mortality rate has decreased generally, but interestingly has risen drastically in the Arima area. Crude mortality rates have increased in areas of high population density, namely Port of Spain, San Fernando and Arima. This is attributable mainly to cancer, diabetes, heart and cardio-vascular diseases - the high incidence of which is associated with lifestyles in developed countries. The increased incidence of cancer, however, is also an indicator of environmental problems as well as changes in life style and increased life expectancy.

The number of cases of gastro-enteritis and tuberculosis (incidence of which suggests poor sanitary and environmental conditions) increased by 69% and 38% respectively during the period 1981 to 1992. There was also a rise in the incidence of food-borne illnesses.

3.3 Poverty

A major challenge which the country must confront in its quest for sustainable development is the phenomenon of growing poverty. The evidence abounds that where inadequacy or lack of income excludes persons from access to markets which provide their basic needs, alternative sources or means are sought usually through the exploitation of renewable natural resources to satisfy the basic needs for food, water and shelter. This frequently leads to environmental degradation because of the overriding short-term perspective. Evidence of that link in Trinidad and Tobago is most clearly demonstrated by the growth in squatting settlements. Historical patterns of inaccessibility to affordable land for significant sections of the population may have exacerbated the problem of squatting.

3.3.1 General Trends

Since the 1980’s, Trinidad and Tobago has experienced a general increase in poverty from 3.5% in 1981/82 to 14.8% in 1988. Studies, based on 1992 data, indicate that present levels of poverty are much higher, between 21% (based on World Bank's (1995) definition of the poverty level) and 38% as calculated by the Ministry of Social Development in 1996.

3.3.2 A Profile of the Poor.

The characteristics of the poor population are similar, for both Trinidad and Tobago. Roughly half the poor is ‘extremely poor’ or indigent - that is, they cannot afford the cost of a minimum low-cost food basket. Generally, as expected, employment rates and education levels are lower for the poor. Moreover, poor households are larger and support more children. Few poor persons are professionals. The major occupational groups which poor persons occupy are craft, machine operators and other elementary occupations. Levels of poverty are higher in households which are:

(i) headed by females;

i. headed by persons who are described as mixed or are of African descent;

iii. headed by persons who have had up to Junior Secondary schooling, less or none at all; or

iv. whose heads are unemployed, have never worked or

are less than 24 years of age.

Although there are more poor households in rural areas, the incidence of poverty in urban areas is slightly higher and more severe. Almost half the poor population resides in the former County St. George (43.5%), the most densely populated, urbanized and the fastest growing county. The extremely poor population is fairly evenly distributed between urban and rural areas.

3.4 Patterns of consumption

3.4.1 Natural Resources

Consumption here refers to the transformation of materials and energy less of which will be available for future use whether renewable or not. Consumption patterns impact on biophysical systems and through these impacts may threaten the health and well-being of humans and other living organisms by the effects of contaminants on land, in air and in water. The increased consumption of petroleum products conversion of forested land to food crop, rice and sugar production and residential development are all trends in consumption which contribute to environmental degradation.

3.4.2 Plastics, Paper And Glass Recycling

Between 1991 and 1996, a total of some 47,325 tonnes of polyethylene resins, used in the manufacture of plastic bags, were imported into the country. There has been a general increase in all plastic consumer goods over the last five years. Plastics constitute a large percentage of all waste collected and disposed. It is estimated that households generated 64,000 tonnes of plastic waste in 1996. Although its chemical stability limits the threat of toxicity, high usage and its non-biodegradable nature pose a serious problem for solid waste disposal.

In recent times, recycling of paper and glass has become a profitable business venture. In addition, there is a small amount of recycling of plastic, iron and steel, copper and aluminum. Initiatives are being pursued to promote recycling programmes in schools. The potential for increased recycling is appreciable. Collection, however, presents a serious challenge since in Trinidad and Tobago there is virtually no systematic sorting of solid waste,

particularly at the domestic level. This is one of the early steps that needs to be taken in regulating solid waste handling in the country.

3. Waste Disposal

Increase in population, rapid urbanisation and industrialisation and changes in the patterns and levels of personal and household consumption have generated an increase in the quality and quantity of solid waste and consequently created the need for additional disposal sites and new approaches to waste management. A daily average of 936 tonnes of solid waste is disposed of at the major landfill sites in Trinidad and Tobago. Of particular concern is the absence of a properly managed system for the handling of hazardous wastes. The urgency of this cannot be overemphasized, notwithstanding an initiative now being pursued through the Ministry of Planning and Development.

3.4.4 Tourism and Recreation

Tourism is a relatively underdeveloped sector of the economy of Trinidad and Tobago. Its contribution to GDP, employment and exports is currently small but growing rapidly as it becomes the focus of more deliberate policy and programme intervention on the part of the government. The nature of the tourism product (and consequently the spatial concentration) varies between Tobago, where it is based on the coastal environment particularly in the south and south west, and Trinidad, where the focus is on cultural diversity and terrestrial resource attributes.

The coastal zone, forests and rivers are also important for recreational purposes. Many of these resources are intensively used by the population and are despoiled by littering and dumping of waste. Emerging mandates for the management of these resources are adding to the problems already experienced.

3.5 Environmental Effects of Demography and Socio-Economics

The overall growth in population has serious implications for the demand for natural resources with the most basic being arable land, water and land for housing. Urbanization has consumed the most readily available flat land in certain areas, particularly in the northwest, and along the East-West Corridor in Trinidad. In northwest Trinidad, over the years, formal and informal human settlement and agricultural activities have expanded upland, often in areas with a slope gradient higher than 30 degrees. In the Diego Martin watershed, for example, where urbanization has resulted in the use of a significant proportion of upland areas for housing, clearing of the forest cover and inadequate land grading for housing have increased the amount and rate of water run-off, erosion, soil loss and siltation of waterways, sometimes leading to downstream flooding and infrastructural damage. Occasionally too, there is loss of human life. Containment of discharge in developed areas has necessitated extensive canalization requiring boulders and aggregate.

The occurrence of bush fires is another serious problem. The fires, often deliberately set to clear land for agriculture or to dispose of household waste, have caused deforestation, air pollution and in some instances loss of property. Negative impacts on perennial streams and ground water supply are evident in areas of severe deforestation in Trinidad and to a lesser extent in Tobago.

The proliferation of informal housing settlements is however not limited to any one geographic location. These spontaneous settlements are distributed throughout the country, particularly around the urban centres. It is estimated that 20% of the population lived in irregular settlements in 1985 and that this increased to 25% in 1990.

There is, therefore, limited or absent infrastructure for water supplies, waste and sewage disposal, and in most cases, access to good social services, especially health care and education, is poor. These infrastructural inadequacies have been linked to the incidence of infectious illnesses such as skin rashes and ringworm.

In Trinidad and Tobago, a tradition or an ethic of promoting proper natural resource use has not yet been developed and nurtured at the level of the individual citizen. A culture of pollution is in evidence as improper garbage disposal, both from recreation sites and homes, have caused almost irreversible damage to some rivers and water courses. Additionally, informal and illegal dumpsites dot the landscape, in urban and rural areas alike, particularly on hillsides. This activity is pervasive encompassing all social and economic strata. Some industries as well appear to have developed based on this culture of pollution. Enforcement of litter and pollution laws is also inadequate.

4.0 LAND

4.1 Introduction

The term "land" in this report includes the combined physical and biological features of the earth's surface; that is, topography, terrain, physiography and natural resources such as soils, minerals, and a wide range of ecosystems. Trinidad and Tobago is particularly well endowed with natural resources when compared with islands of similar size elsewhere in the tropics. It possesses a wide range of soils distributed over its relatively small area and formed from five main groups of geological parent materials: igneous rock, metamorphic rock, sedimentary rock, alluvial and colluvial deposits and volcanic formation. These provide a variety of materials, which include limestones, clays, sands and gravels. A total of 120 different soil types have been recorded for Trinidad and 42 for Tobago. The associated range of ecosystems includes varied forest types, savannahs, wetlands and mudflats.

4.2 Land Area

Trinidad’s land mass is approximately 4,820 square kilometres with average length of 88 kilometres and average width of 59 kilometres. That of Tobago is approximately 303 square kilometres with an average length of 43 kilometres and maximum width of 12.5 kilometres.

4.3 Land capability

Categorisation of land by capability criteria is an approach adopted to determine the value of land for a particular use. While a system has been developed for assessing the capability of land for agricultural production in the Caribbean (and utilized in Trinidad and Tobago), none has been done for other types of land use. The system for agriculture has its basis in a design for mechanized agricultural production and soil conservation for determining the maximum intensity of land use in relation to erosion risks and sustained productivity. It considers relief, climate and the physical, chemical and biological properties of soil. On the basis of this classification system, locations having the largest number of alternative uses, under a given system of management, are placed in Class 1 while those with the least number are assigned to Class VII.

In Trinidad, Class V land commands the largest area of approximately 119,723 hectares while the Class I category covers the smallest area of approximately 2,145 hectares. 90% of lands in the Northern Range fall within Classes VI and VII which are lands that should be left under indigenous growth or forest.

4.4 Hydrocarbons

Trinidad and Tobago has an abundance of hydrocarbon resources relative to its area and population size. The resources of the southern-most area of Trinidad are best known and formed the basis of the country’s petroleum economy up to the 1980s. In this area two classes of hydrocarbons occur in commercial quantities - asphalt and crude oil (Map 4 - 1).

4.4.1 Asphalt

The 46 hectare Pitch Lake at La Brea is one of the well-known deposits of natural asphalt in the world. It was first used locally for road surfacing in 1815. The present depth of the lake is estimated at 87metres and at current extraction rates, it is expected to last another 400 years.

4.4.2 Crude Oil

Although the first known oil well in Trinidad was drilled in 1866, commercial oil production only commenced in 1908. Up to the early 1950’s production was confined to reservoirs under the land area. (Exploitation of fields in the Gulf of Paria began in the 1950’s and

the fields off the east coast were discovered in 1968). Today, programmes for secondary recovery from land operations have been initiated to extract formerly uneconomic deposits. At current rates of production known reserves of petroleum are expected to last to 2017.

4.5 Inorganic minerals

There are no known economic deposits of metallic minerals in Trinidad and Tobago. Other than the hydrocarbons, only non-metallic minerals are of economic value. The more important among these include limestone, sands and gravels, clay, porcellanite and tar/oil sands. Minor minerals include gypsum, soft coal and manjack.

4.5.1 Limestone

There are three main types of limestone found in Trinidad and Tobago. The Laventille formation is found only at Laventille, Point Gourde, and some of the offshore islands in the area. It is the only material in Trinidad suitable for calcining.

The Rio Seco or "blue" recrystallized limestone formations occur throughout the Northern Range from the Santa Cruz Valley eastward. These limestones are hard and dense and are well suited as road aggregates and building material. Rubble "yellow" reefal limestone occurs in the Central Range. This yellow limestone which is utilized for the manufacture of Portland cement, is a prime mineral asset.

4.5.2 Sand and Gravel deposits

Extensive deltaic deposits of the "Melajo" and "Guanapo" gravels occur from Wallerfield through Valencia to Matura in the eastern Northern Basin. The quartzitic sands also found throughout this area include a valuable deposit of silica sand at Matura used for the manufacture of glass. Additionally, deposits of fine-grained plastering sand occur where the aquifers at the southern margin of the Northern Basin outcrop, and at scattered localities elsewhere. Unlike Trinidad, Tobago has no alluvial deposits of sand. Some of the sand used for the construction industry is obtained by sand

mining on beaches and in river beds, particularly the Richmond and Goldsborough beaches and the Goldsborough River.

4.5.3 Clay Deposits

Clay deposits are concentrated in the Northern Basin. They are used for the production of structural ceramic. The main use is in the production of fired hollow clay blocks. The extraction of clay and production of these blocks are carried out at Longdenville in west-central Trinidad.

4.5.4 Porcellanite

An unusual formation of naturally burnt clays with pozzolanic properties, which can be used in the manufacture of Portland Cement, occurs between Granville and Buenos Aires in the southwestern peninsula of Trinidad.

4.5.5 Tar/Oil sands

Deposits of tar or oil sands, which are used as road surfacing material, occur in the Southern Basin, mainly in the area south of La Brea. These deposits are associated with hydrocarbons found throughout this area, mud volcanoes and natural oil seepages.

4.6 Impacts of Land Use on the Environment

Land use in Trinidad and Tobago illustrates a complex pattern. Notwithstanding this, four major uses are evident, namely: forest, agriculture, mining and human settlements, either pure or in combination with other uses. A thirty-year comparison of land use between the 1960s and 1996 indicates that the most significant change which took place over the period is that forests and agricultural lands have declined, pure stands of forests having been replaced by broken forests, grasslands, settlements and other built development. A major concern is the loss of forests from steep slopes, watershed protection areas and water production areas as a result of quarrying activity, farming, forest fires and squatting.

Land under agriculture has declined primarily because of abandonment of agricultural estates, encroachment of settlements and a decline in the number of active farmers.

4.6.1 Agriculture

Inappropriate agricultural practices on all categories of slope, particularly very steep slopes, have resulted in severe environmental problems. The main issues and problems are squatting, slash and burn practice, soil mismanagement and agrochemical abuse.

Squatting for agriculture is widespread in the country. The main areas affected are the Southern Watershed Reserve (sugarcane cultivation), the Northern Range (cultivation of a wide variety of short-term crops), the Nariva Swamp (cultivation of a variety of crops) and the Courland Watershed in Tobago (cultivation of short-term crops). Squatting is especially prevalent on State lands.

Slash and burn or shifting cultivation is also widely practised. This practice is mainly influenced by land tenure and is especially prevalent amongst squatters on State and private lands or where there is a short-term lease e.g. in the valleys of Santa Cruz and Maracas in Trinidad; and Hope, Mason Hall and Mt. Marie in Tobago, the latter affecting the Hillsborough West River.

Conventional soil conservation is either lacking or poorly effected. Soil management as practised by many of the farmers using the slash and burn method is due to lack of knowledge, cost and the feeling that some methods may take ‘valuable land’ out of production. Farmers in the Central Range plough downhill to till the soil rather than across the slope, since it is felt that this method is ‘easier’ on the machine.

A wide range of chemicals is employed and frequently used inappropriately. Pesticide and fertilizer use in a recent study showed that nitrate (which is very mobile) and ammonium ions can move to a depth of 45 centimetres in a sandy loam soil within one week after nitrogen fertilizer application. The records indicate that on average 1,500,000 kilogramme of pesticides are imported for use in the agriculture sector annually. Some of these pesticides persist in the soil, reaching toxic levels, which may limit soil productivity and fertility. One of the most frequently used herbicides in Trinidad and Tobago, paraquat, binds strongly to clay in soils and may persist for up to thirteen years in some soils. There is therefore a real risk of contamination of surface and ground waters.

4.6.2 Human Settlements

Both formally approved land settlement schemes and informal squatter settlements contribute to environmental problems in Trinidad and Tobago.

A substantial level of squatter settlements occur and these contribute to erosion of land on hillslopes, poor drainage and flooding, inadequate garbage disposal and collection practices, inappropriate sewage treatment and disposal, increased forest fires on hillslopes and poor aesthetics.

Many of the formally approved land settlement schemes do not follow soil-engineering specifications to prevent or reduce soil erosion. Drainage channels often cannot accommodate the increased runoff from the settlements, especially those on the steeper slopes (with gradients higher than 30o). The maintenance of infrastructure, particularly sewage treatment plants, has had a very poor track record. Over the years, package sewage treatment plants required for housing developments have been poorly maintained with no individual, company, agency or institution being legally responsible while the public at large is exposed to odours and raw or inadequately treated sewage from these malfunctioning plants.

Buried and open landfill sites put stress on the environment. The managed sites at Beetham, Guanapo, Forres Park in Trinidad and Studley Park in Tobago, only partially address the environmental concerns. There is, for example, inadequate control of seepage as well as unauthorized burning at these sites.

Most of the existing solid waste dump sites are unauthorized and are often located in areas that are difficult to access for remediation e.g. at the bottom of the precipice of a steep hillside or in a gorge where the waste does not only cause unsightliness and emit odours, but inevitably leads to blockage of the water course.

It is almost impossible to institute the level of surveillance required to deal with illegal dumping which therefore causes extreme difficulty in apprehending violators. Part of the remedy for this and many of the other environmental ills must no doubt be sought in public education.

4.6.3 Mining

1. Beach Sands.

The extraction of beach sand from coastal areas and riverbeds of Tobago has in the past been unregulated. Recently attempts have been made to reduce extraction. Some sand has been produced collaterally with rock quarrying but the product is not widely accepted. Continued concern is expressed at beach sand mining particularly the negative impact on coastal activities and real estate. Alternative approaches to sourcing of sand for construction purposes are still being reviewed.

4.6.3.2 Land-based Petroleum

Petroleum mining has been the dominant influence on the economic development of Trinidad and Tobago during the twentieth century. At the beginning of 1995, proven reserves of crude oil were 218 million barrels, giving a reserve life of approximately 20 years at current production rates.

The petroleum and petrochemical industries contribute substantially to the overall development of the country. However, the operation of production wells and refinery facilities pollute the land resources through the effluents and solid wastes they generate from daily activities and some accidental seepages. Past activities carried out when explicit environmental management concerns were not evident together with natural seepages contribute to environmental problems.

Land-based petroleum activities are concentrated in the south of Trinidad. With the recent discovery of petroleum in the centre of

Trinidad the possibility exists for an extension of such problems into these areas if exploitation commences. Some of the land-based pollution problems derive from seasonal inundation of the flood plains with overflows from rivers containing refinery effluents and crude oil components. Evidence of this is seen on lands adjoining the Godineau, south Oropouche and Pilote rivers.

Abandoned drilling sites scattered throughout the south of Trinidad - La Brea, Palo Seco, Fyzabad - were part of the crude oil production fields of the past. The technique used then to cap wells was unsustainable and, with time, many abandoned wells started seeping as evidenced in the Trinity Hills and at the proposed La Brea Industrial Estate.

The solid and semi-solid wastes from petroleum refining contain oil, heavy metals and other potentially toxic substances. Recent initiatives have been taken to establish waste treatment systems based on bio-remediation - a process using naturally occurring micro-organisms to degrade harmful chemicals into non-toxic compounds.

The use of petroleum products also contribute to environmental problems, the greatest concern being with the disposal of used vehicle oils into drains, rivers and streams which degrade surrounding lands.

4.6.3.3 Quarrying

Quarrying predates petroleum mining in the history of Trinidad and Tobago but its development closely parallels the development of the oil industry. There are over 50 quarries in Trinidad occupying approximately 2,300 hectares of land, 37 of which are located on State lands. Of the 50 quarries, fourteen are abandoned or closed. The types of materials extracted are varied and include gravel, sand, sharp sand, plastering sand, oil sand, pitrun, limestone aggregate, blue limestone aggregate and pottery clay.

The problems resulting from quarrying activity include loss of habitat (and consequently of flora and fauna), water pollution, air and noise pollution and poor aesthetics. As described earlier, the quarry materials exploited occur in different parts of the Northern Range, Northern Basin, Central Range and Southern Basin. The negative effects on the environment are consequently associated with their distribution. Since most of the quarries occupy State land it should be easier to regulate quarrying activity and overcome environmental problems. There has been no single body however,

with overall responsibility for the industry, nor are there adequate environmental protection clauses, proper administrative support, enforcement of lease terms and legislation to minimize these problems. At present, though, the Ministry of Energy and Energy Industries is actively pursuing the formulation of new legislation and strategies to address these inadequacies.

5.0 FRESHWATER

5.1 Introduction

Trinidad and Tobago’s climate is typical of the wet tropics with two pronounced seasons, wet and dry. This seasonality is determined by the annual north to south migrations of the inter-tropical convergence zone (ITCZ). This is an organized system with which is associated heavy showers that contribute the major proportion of total annual rainfall. Rainfall quantities and distribution have profound effects on availability of water resources and consequently on human, social and economic development, and land management. Periodically, dry seasons may be severe placing stresses on potable water supplies and favouring forest fires.

5.2 Surface water

5.2.1 Watersheds

Annual rainfall is estimated at 9,000 million cubic metres 7,800 million cubic metres are lost by evapo-transpiration. Rainfall is unevenly distributed ranging from highs of about 3,500 mm in mountainous regions to lows of about 1,300 mm on the offshore islands of the northwestern peninsula and the southwestern peninsula (Map 5-1). The three mountain ranges in Trinidad form divides which separate drainages to the north, east, south and west. The largest watersheds are those flowing to the west into the

Gulf of Paria and to the east into the Atlantic Ocean. The main rivers in the former are the Caroni and the South Oropouche, and in the latter the North Oropouche, Navet and Ortoire. Although draining substantially smaller areas, the Yarra, Marianne, Paria, Matelot, Shark and Grand Riviere Rivers flow to the north from the highest rainfall areas in the Northern Range. All are perennial, and all are potentially important sources of good quality water. Of the several rivers draining to the south from the Southern Range, only three are perennial, the Erin, Moruga and Pilote rivers (Map 5-2).

The Main Ridge in Tobago forms a divide separating windward and leeward facing watersheds. Rivers in Tobago are generally smaller than those in Trinidad and those draining the Main Ridge are perennial in their upper courses.

5.2.2 Standing Bodies of Freshwater

There are no natural permanent standing bodies of freshwater in either Trinidad or Tobago. There are nevertheless in Trinidad extensive areas of freshwater which appear seasonally in wetlands, particularly in major wetlands such as those at Nariva, North Oropouche, Caroni, South Oropouche, Rousillac and Los Blanquizales. These generally retreat during the dry season and some occasionally dry out completely resulting in fish kills. Where topography permits, there may be permanent standing water at river mouths such as is found at the mouths of the Marianne and Yarra Rivers in Trinidad and the Courland River in Tobago. There are four relatively large artificial lakes established for accumulation and storage of surface waters. These include in Trinidad, the Hollis, Navet and Caroni Arena reservoirs and in Tobago, the Hillsborough Reservoir. Numerous small freshwater ponds for aquaculture and use in industry are also scattered around the country.

5.3 Ground Water

There are significant sources of groundwater available and utilized in Trinidad, especially in northern Trinidad. The more important aquifers lead from the southern side of the Northern Range into the gravel deposits in the floors of valleys and in the Caroni plain. Many of these are successfully exploited. There are many perennial springs in Northern Range valleys and a few scattered artesian upflows on the Caroni plain as, for example, in Orange Grove and Santa Rosa. Ground water reservoirs are also to be found in coarse sand beds along the flanks of the Central Range and several of these are currently exploited. There are also a few scattered perennial artesian outflows in and around the Central Range as

well as fine sand beds in south Trinidad, which have been exploited. Minor aquifers exist in the southwestern part of Tobago but these have not been exploited over the years, as are those in Trinidad. Persistent but minor upwelling of freshwater occurs in the western reef at Buccoo Reef.

5.4 Freshwater Demand

Current demand for domestic water is estimated at 630,000 cubic metres per day expected to rise to 663,000 cubic metres per day by the year 2000. Current demand for industrial/agricultural water is estimated to be 249,000 cubic metres per day and expected to rise to 285,000 cubic metres per day by the year 2000. To meet these demands production will have to be significantly higher owing to leakage within the distribution system, currently at over 40% but projected to be reduced to 25% by March 1999. A 25 year old study suggested a safe total yield of fresh water of about 1,430,000 cubic metres per day - 1,100,000 cubic metres per day to be obtained from surface waters and 330,000 cubic metres per day from groundwater. In addition, water is required for irrigation of approximately 1,200 hectares of land for some five months of the year. It is clear therefore that demands are approaching safe yields and that steps will have to be taken to improve the management of watersheds, reduce leakage in the water distribution system, find additional surface sources and consider recycling of domestic and industrial wastewaters.

5.5 Watershed status and water quality.

The condition of watersheds and their freshwater resources is extremely varied. Many of the Northern Range rivers, especially those draining to the north in the eastern part of the Northern range are pristine, not prone to flooding even though arising in high rainfall areas, and support a rich biota. In contrast, many south flowing rivers of the Northern Range, especially those in the western part of the range, reflect the serious deforestation which has taken place over the past two centuries. Discharge after heavy rain is rapid, causing flooding in valleys and plain, and the necessity in built areas, to canalize rivers at considerable capital cost, as for example in the Maraval and Diego Martin Valleys, is increasing. Combined storm inflows from adjacent watersheds in both Northern and Central Ranges cause serious annual flooding and damage in heavily populated low lying areas. This results in costly flood control measures being undertaken from time to time, particularly embankments and river mouth dredging.

As expected, one critical effect of watershed deforestation is reduction of infiltration to aquifers due to faster runoff. Where aquifers are being tapped in deforested valleys such as for example in the Santa Cruz Valley, recharge may be less than extraction rate, as has been shown in one recent study. In other valleys perennial streams may simply disappear underground, upstream of rural boreholes, during the dry season. Within recent times, the rate of removal of trees from upland forested areas has been increasing and the effects of this will no doubt be felt in the very short term.

5.6 Effects of agriculture and urbanization

While upland streams may be pristine, lowland streams, especially those in agricultural and built-up areas are polluted to varying degrees, and some may at times be devoid of higher life forms. Agricultural pollutants include fertilizers, insecticides, herbicides, fungicides and farm effluents which contain animal wastes and offal. Greywater from households enters storm drainage, which discharge into streams. Greywater includes an extremely wide range of substances used domestically, for example, solvents, pesticides, paints, lubricating oils, household cleaning materials and detergents, fertilizers and domestic wastes such as laundry and bath water, kitchen wastes and outflow from septic tanks and pit latrines. In addition seepage from dump sites and landfills may enter streams. Quarrying and hillside farming also contribute to significant amounts of suspended materials in many streams.

Trinidad, in particular, has a serious and chronic problem with the illegal dumping of solid wastes into lowland streams in addition to substances which enter streams in suspension or in solution. Household appliances and furniture, containers, derelict vehicles, agricultural wastes and offal, and domestic garbage are commonly dumped at bridges and culverts, frequently disrupting stream flow and contributing to flooding. The widespread use of plastic films and containers leads to the ubiquitous presence of these materials in waterways and coastal waters.

Although the lower courses of many rivers draining to the north, the east and the south in Trinidad and all in Tobago are in relatively unpolluted states, those draining into the Gulf of Paria are generally severely polluted. The Caroni drains heavily developed built and agricultural areas and is consequently a receiver of a wide range of pollutants. Most of the rivers and streams receiving from the urban areas within the Caroni River Basin are polluted with a variety of wastes from domestic refuse and sewage, and agricultural chemicals.

(Appendix Ι – Tables Ι - A to Ι - D).

5.7 Effects of Industrial Activity

Industrial/commercial activity is extremely varied and as there are no enforced effluent standards, virtually anything may be found in the receiving streams and waterways. These may include wastes from the food and beverage industries which increase Biological Oxygen Demand (BOD) and create anoxic conditions; or wastes from manufacturing and packaging activities, such as solvents, petroleum products, dyes and industrial chemicals. Heavy industry may from time to time spill hydrocarbons and manufactured chemicals. Solid wastes, including catalysts, bulk chemicals, heavy metals and pesticides on site may be leached to streams and waterways.

For decades the Guaracara River has been chronically polluted with oil wastes and spills from the refinery, while the Guapo River has suffered from well leakages. Similarly, the Cipero River has been polluted seasonally in crop time with wastes from sugar production. The Couva River has suffered from effluents from the sugar factory and in the last decade from the effluents of the Point Lisas Industrial Estate as well. Some of the pollution effects which have been reported and which may reflect industrial pollution, include lesions, cancerous tumours and cataracts in juvenile fishes, as well as destruction of sea grass beds and coral reefs.

5.8 Effects of Domestic Sewage

Of critical importance in the country is the general problem of treatment and disposal of domestic sewage. In rural areas pit latrines are still widely used. Although some urban areas are served by state-run sewerage systems, suburban residential areas are generally served either by individual septic tank systems in older developments, or package treatment plants in newer developments, a requirement of the Water and Sewerage Authority (WASA). There are essentially four central sewered areas in Trinidad viz. western Port of Spain, (Bayshore, Diego Martin, Western Main Road, St. James and Maraval); east of Port of Spain (including Barataria, San Juan, Mt. Hope and Arima); districts in the South (including San Fernando, Pleasantville and Marabella); and Tucker Valley in Chaguaramas. There are over 140 package sewage treatment plants (STPs) throughout Trinidad and over one dozen in Tobago.

Malfunctioning systems are extremely common and it is not unusual to see upwellings of raw sewage in public places. Map 5-3 shows the functional and non-functional sewage treatment plants as recorded in 1991. Most of the packaged plants were to have been taken over by WASA after completion of the development but to date the Authority has generally been unable to do this. At present most of these are non-functional and deliver raw sewage to watercourses and the sea. Up to 1991, for instance, 21% of the STPs in Trinidad were non-functional while in Tobago, 81% of STPs were either non-operational or poorly maintained. The plants at Buccoo and Bon Accord have been non-functional for the past decade and deliver raw sewage to and cause undesirable effects in the marine community. Chaguaramas is similarly contaminated.

5.9. Effects of Domestic Greywater

One critical problem not widely appreciated in the country is that associated with the disposal of domestic greywater, consisting mainly of kitchen, bath and laundry water. For example, during the dry season, the lower courses of streams may cease to flow altogether because of the build-up of scums and solid matter. In the absence of stream flow, anoxia develops from increased BOD and results in fish kills of gill breathing fish and invertebrates, decay of which further increases BOD. Build up of faecal coliform bacteria and other pathogens places users of such waters at risk of serious disease.

Domestic greywater is generally disposed into the storm drainage system where it enters streams. It accounts for almost 80% of BOD, over 65% of suspended solids, approximately 30% of total nitrogen and over 85% of total phosphorus, of total domestic wastewater. Good practice requires that all domestic wastewater, both grey and black be discharged to on-site or central treatment facilities, a practice widely accepted in the developed world. In the wet season water courses are flushed of pollutants and fish and invertebrate populations replenished from cleaner upstream sources. This flushing, however, is not without further effect as the pollutants are transported to coastal areas where they may affect marine biota and continue to be a hazard to persons using coastal waters.

6.0 COASTAL AND MARINE ENVIRONMENT

6.1 Introduction

The location of Trinidad and Tobago on the continental shelf of South America and immediately adjacent to the outflow of the Orinoco River determines to a great extent the nature and form of its coastal and marine environment. Its location on the continental shelf explains why much of its exclusive economic zone lies in shallow enough depths to permit exploitation of petroleum, natural gas and other seabed resources, while outflow of the Orinoco delivers land-derived nutrients and sediments to the shelf which support significant fisheries resources.

6.2 Bathymetry

The bathymetry of the Caribbean area is particularly well documented and is available in navigational charts of the British Admiralty and United States Navy. The general bathymetry of offshore and nearshore waters of Trinidad is also comparatively well documented. This is not to say that it is not necessary to continue detailed hydrographic surveys. Map 6 - 1 illustrates Trinidad and Tobago’s bathymetry in relation to its exclusive economic zone. Instability of nearshore conditions leading to erosion and siltation produces changes in bathymetry, while errors made prior to availability of electronic sounding and satellite positioning continue to need correction.

6.2.1 Gulf Of Paria

The Gulf of Paria is probably the most lacking in topographic irregularities. It is a shallow semi-enclosed sedimentary basin with an average depth of 20m and maximum depths in the centre of about 35m rising gradually to the coastlines of western Trinidad and eastern Venezuela. While mostly featureless, the seabed adjacent to the islands off the north-western peninsula displays a range of bottom types and some varied topography. Some steep-sided troughs are found with depths exceeding 200m in the Bocas passages. Sea bottom consists mainly of mud but there are scattered patches of shell debris.

6.2.2 North and East Coasts of Trinidad

The sea bed to the north of Trinidad shelves gradually with the 200m contour being some 60 km offshore. Nearshore sea bottom may be firm mud to sand, but offshore the sea bottom is mainly mud. The sea bed to the east of Trinidad and between Trinidad and Tobago is extremely varied in type and topography. On the east, it dips more gently downward from the coast towards the edge of the continental shelf approximately 100 km away, than on the north coast. Prominent features include the Manzanilla Bank running east to Darien Rock, the Drew Shallows between Toco and Tobago, and the Emerald Shoals and Delaware Bank east of Toco. These are all hard bottom banks supporting algal growth and coral reefs.

6.2.3 Columbus Channel

In contrast, the Columbus Channel separating the south coast of Trinidad from the mainland is a comparatively shallow current-worn channel with depths of about 25m and with varied bottom types ranging from mud to mudstone. In the navigable area that exists throughout the length of the Columbus Channel, mid-channel depths reach 77m. The seabed slopes gently downward from both the Trinidad and Venezuelan coasts.

6.2.4 Tobago

Topography at the north eastern part of Tobago is precipitous with the 200 m contour being within 7km of the coast line. The bathymetry off the south and north coasts of Tobago resemble that off the east and north coasts of Trinidad respectively. With the exception of Drew Bank off southwest Tobago, there are no significant bathymetric features.

6.3 Main Circulation Patterns

The circulation around Trinidad and Tobago is very complex. Most of the knowledge so far acquired is of horizontal circulation with only little knowledge of circulation within the water column. The main patterns are depicted in Map 6 - 2.

The dominant current influence in Trinidad and Tobago is the northern branch of the South Equatorial Current, the Guiana Current. This consists of a broad stream of oceanic water flowing along the north eastern coast of South America. To this stream is added the variable outflow of several rivers. Owing to its proximity, the Orinoco River is the major influence in Trinidad, particularly in the Gulf of Paria. As the Guiana Current approaches Trinidad and Tobago it divides into two streams, with the inner stream passing into the Columbus Channel in a predominantly westerly flow and then into the Gulf of Paria, while the outer passes up along the east coast of Trinidad and through the Galleons Passage into the Caribbean Sea. Residence time of the Gulf of Paria stream is about ten days if travelling within the mid-Gulf current stream, longer, if closer to shore. The two streams unite north of the Bocas to form the Antillean Current which flows into the Caribbean Sea. The streams move at velocities of up to two knots in the open Atlantic and up to 1.5 knots in the Gulf of Paria. Nearshore, as for example at the north eastern tip of Tobago, and on the Drew Shallows, velocities may be even higher. The passage of the Guiana Current/Orinoco River discharge through the Columbus Channel has a powerful erosional effect on the south coast of Trinidad. There is distinct evidence that the Orinoco River influences both the

southern and northern coasts of Tobago, but the field data is inadequate to precisely describe these features.

6.4 Tide and Wave Regime

6.4.1 Tides

The tidal regime is a semidiurnal one with periods of approximately 12.5 hours. While in the wider Caribbean Sea and adjacent Atlantic Ocean tidal range is approximately 10 cm, Trinidad and Tobago experiences higher tidal ranges. This is because the islands are situated on the continental shelf. At high spring tides the maximum range is 1.2 m with some slight variation from north to south. There is also some variation of timing of highs and lows at different parts of the coast.

6.4.2 Waves

Trinidad and Tobago is subject to wind driven waves, generally from the east but there is some seasonal variation associated with changes in the trade winds. Open water swell is normally about two meters, but irregular swell may be experienced at any time being generated by storm activity such as hurricane or extreme winter storm. This wave regime is typical for this latitude.

Waves approaching the islands are generally from the east, shifting to the northeast during the months of December and January. During most of the wet season waves move generally from the southeast. Between November and March which coincides with the period of winter storm activity in the North Atlantic Ocean, waves are generally higher.

On the east coasts of both Trinidad and Tobago, sea conditions are difficult at all times. From January to May conditions become difficult along the north coast of Trinidad and on the leeward coast of Tobago where swell may cause damage to the upper layers of coral reefs. The Gulf of Paria is sheltered with generally very low wave energy levels. The land mass of Trinidad shelters the eastern side of the Gulf which consequently does not experience significant swell except during the winter storm activity in the Atlantic when some northerly swells make their way through the Dragon's Mouth and large swells are reported in the Gulf.

6.5 Water Quality

Water quality in Trinidad and Tobago is impacted by activities both on land and in the marine areas. Most of the contaminants investigated focused on the macro-pollutants such as hydrocarbons and heavy metals with little information regarding other pollutants.

6.5.1 Pollutants

In Trinidad, evidence of petroleum hydrocarbon contamination exists in all coastal waters from natural oil seeps or petroleum mining operations. On the south and north coasts as in the waters around Tobago, contamination is believed to result from shipping activities, ballast discharge and oil spills from tanker traffic. In the coastal waters of the Gulf of Paria there are varying degrees of contamination from petroleum hydrocarbons and heavy metals. The higher concentrations of petroleum hydrocarbon (200 to >500µ g/g dry wt. Chrysene equiv.) are evident in the vicinity of runoff from drilling or refinery operations. The concentrations of heavy metals are even higher in the wet season, suggesting that during this time runoff from land is a greater source of heavy metal contamination than offshore fields. On the east coast of Trinidad which has a more recent history of oil exploration and production than the west, most of the oil-related activities are offshore and it is, therefore, not surprising that there is little evidence of petroleum hydrocarbon contamination from land-based sources.

6.5.2 Salinity.

Water quality is much influenced by the Orinoco River which displays marked seasonality of discharge as indicated by surface salinities in the wet (Map 6-3) and dry (Map 6-4) seasons. Peak discharge takes place between August and October but shows some variability in timing as well as in volume. In most years at these times salinities in the Columbus Channel and in the nearshore waters at Icacos and Cedros fall to approximately one tenth, and in the Gulf of Paria to about one half that of oceanic seawater. Along the east coast there is also considerable dilution

and mixing. At Galera salinities may fall to three quarters that of oceanic seawater. The effects in Tobago are not as severe but at Crown Point salinity may fall by one or two parts per thousand.

Associated with this seasonal dilution of nearshore waters from riverine discharge are stratification in the water column and a significant increase in turbidity due to suspended sediments, both organic and inorganic, some of which originated several hundreds of kilometers upriver. This drastically reduces light penetration and in extreme instances light may disappear at the comparatively shallow depth of 35m. Occasionally, organic flocculations may completely coat the substratum in sheltered places and cause dieback of coral communities, as happened at Buccoo Reef in the early 1970s.

A notable feature of Orinoco discharge is floating vegetation torn from along the river banks far inland. This phenomenon is thought to be responsible for colonization of the southwestern peninsula by both plants and animals.

6.5.3 Temperature

The temperature regime is extremely stable with average sea surface temperatures ranging from 26.5oC (dry season) to 28oC (wet season). Nearshore and in sheltered places temperatures may be higher.

6.6 Sediments

Surface sediments indicate high levels of contamination with hydrocarbons on the west coast of Trinidad, probably due to contaminants from land-based operations transported via the Guapo, Vance, Oropouche and Guaracara rivers. Bioavailable metals have been generally found to be below the concentrations necessary to evoke toxic responses in marine benthic organisms. In contrast, barium levels on the east coast of Trinidad are relatively high due to drilling activities. The windward beaches of Tobago exhibit high tar levels.

6.7 Coastal Form

There has been considerable perturbation of much of the coast of both Trinidad and Tobago, associated with settlement, agricultural enterprise and general economic development. While parts of individual coastlines have remained intact owing to topography or soil type there has been extensive change to vegetation, coastal form and outline, and nearshore bathymetry.

The Gulf of Paria coastline is generally of low elevation and between Port of Spain and San Fernando consists mostly of un-consolidated sediments. Southwards from San Fernando the coast is more varied and consists of a series of low cliffs broken in places by mangroves and beaches. Prominent headlands of more resistant material are to be found at Brighton, Point Fortin and Cedros Point. Westwards from Port of Spain the coast is precipitous in places and broken by small mangrove swamps which have been mostly reclaimed. Nowhere along the Gulf of Paria coastline is there nearshore water naturally deep enough for ocean-going shipping close to centres of human settlement and economic activity. The Gulf of Paria is navigable from north to south, though the presence of uncharted offshore oil installations poses some challenge.

The North Coast, as visually spectacular as it is, is the least varied of the coast lines of Trinidad, and comparable at best with much of the coast of Tobago. It consists mainly of a series of cliffs and headlands interspersed with small beaches. Where soft rock strata occur erosion has created deeply indented bays, as at Maracas and Las Cuevas in the west. To the east the topography is less precipitous and the headland and beaches are smaller and more numerous.

Trinidad's East Coast is extremely varied with three stretches of low coast separated by prominent headlands at Manzanilla Point and Radix Point. Much of this coastline consists of beaches and the central stretch, the Cocal or Manzanilla Beach is typically a barrier beach behind which east flowing rivers have ponded the extensive Nariva freshwater swamp. To the northeast the coastline is higher with cliffs and small beaches.

The South Coast is less varied. To the east the foothills of the Trinity Hills fall abruptly to the sea but to the West the topography is less precipitous and there are extensive beaches, many of which are cliff-faced. Because of the strong and sustained westerly flow in the Columbus Channel, the coastline is under severe erosional pressure, compounded by the nature of the mostly unconsolidated sediments to be found along the coastline.

Tobago’s coastline is very similar to that of Trinidad's North Coast except in the south west. The south west consists largely of a fossil coral platform of about 20 metres depth.

6.8 Coastal Development

Most of the settlement and economic activity in the country over the past two centuries have been along the coast of the Gulf of Paria and in southwestern Tobago and consequently the most extensive changes to be seen here are associated with population centres. Except for mangroves, most of the coastal vegetation of the Gulf of Paria has disappeared, giving way to crops such as sugarcane and coconuts. The rest of the coast line has given way to the full range of housing, farming, industry, public services, transport, land reclamation, solid waste disposal and recreation. Changes along the other coasts have been less severe. The least affected areas have been generally inaccessible, precipitous coastline stretches along the North Coast of Trinidad and around Tobago. Much of the north coast and the east coast of Trinidad has, however, been exploited for agricultural purposes, cocoa and coffee in the north and coconuts in the east. The eastern part of the South Coast, excluding the developments at Guayaguayare, remain generally intact, but agricultural development comparable with that along the North Coast persists to the west between Moruga and Icacos. Southwestern Tobago has been extensively perturbed with human settlement, the mainly agricultural nature of the early economy and the more recent development of tourism.

6.9 Marine Resource Exploitation

6.9.1 Petroleum and Natural Gas

In terms of GDP, petroleum and more recently natural gas have been the most important non-living resources extracted from marine areas during the past four decades, mirroring the decline of land-based petroleum which has been exploited for almost a century. Exploration activity continued offshore during the last five years and is expected to expand over the next five years, with the principal focus in the east coast marine area (Map 6-5). Additional exploration is expected in the north coast marine area. Since 1992 activity within the sector has grown as new investors and existing operators have been taking advantage of the new incentives provided through reform of the tax regime. Exploratory drilling has

more than doubled since 1992 due to the considerable volume of seismic data acquired.

Reserves of marine crude at January 1995 were 10 trillion cubic feet giving a reserve life of approximately 9 years at current rates of production. At present there are 14 producing oil and gas fields offshore. Crude oil production in 1995 averaged 100,674 barrels per day valued at approximately US $590 million for the year.

At December 1995 proven reserves of natural gas were 18.78 trillion cubic feet, giving a reserve life of over 45 years at current rates of production. There are at present 10 fields producing gas in commercial quantities. In 1995 production of natural gas was 560 million standard cubic feet per day (MMscfd) giving an annual value of US $194 million. This production level was commensurate with an increase in the consumption level. With the commissioning of new methanol and ammonia plants in 1996 both these levels have increased further.

Pollution of the marine environment by petroleum and petroleum products is a widespread and important international concern as major events can have devastating effects on marine organisms, particularly seabirds and shellfish, and systems, especially coral reefs, rocky shores and beaches. Fortunately, the country has been spared a major spillage from land-based facilities, producing wells and tankers. There has, however, been persistent pollution of nearshore waters at Pointe-a-Pierre and Guapo, associated with refinery operations. On the other hand in the Mayaro/Guayaguayare oil producing areas, both on land and undersea, there are natural seepages which find their way into the marine environment.

6.9.2 Fisheries

Trinidad and Tobago is situated on the continental shelf of South America and consequently has extensive areas of shallow sea amenable to exploitation of fish and invertebrate stocks. In addition productivity is generally higher owing to nutrient enrichment from South American rivers. The main areas of exploitation are the Gulf of Paria, the Columbus Channel and the North Coast. The East

Coast resources are exploited mainly by larger vessels, many of which are of foreign registration (Map 6-6).

Although relatively small in comparison with other sectors of the economy, the fishing industry is of considerable importance in coastal settlements, especially those in the Gulf of Paria. Over the years coastal stocks of fish and crustaceans have sustained artisanal, semi-industrial and industrial exploitation. The most important artisanal fishery is that for carite, kingfish and sharks, but a smaller scale artisanal fishery exists for marine molluscs and crustaceans. Semi-industrial multi-gear fishery targets snappers, groupers, kingfish, dolphin fish and sharks on the north, south and east coasts of Trinidad. Industrial and semi-industrial shrimp trawlers operate off the north, south and west coasts of Trinidad and an industrial longlining fleet exploits the tuna and swordfish resources of the east coast. A recreational fishery operating off the north and west coasts of Trinidad targets both pelagics (carite, kingfish, cavalli, wahoo, tuna, billfish) and demersals (snappers, groupers, sharks, salmon and croaker).

In Tobago, the two main fisheries are the flying fish fishery and the fish pot fishery which targets mainly snappers and groupers. Sea cockroach/pachro, queen conch, whelk and lobsters are exploited at the artisanal level. Lobster and snappers are occasionally exported to the hotel industry in Barbados and other Caribbean islands.

The north coast shelf is influenced by the inshore upwelling system associated with the Caribbean Current and is therefore relatively highly productive. The South Coast/Columbus Channel encompasses the "Joint Fishing Zone", an area shared between Trinidad and Venezuela and is heavily influenced by seasonal discharges from the Orinoco River. The inshore parts of the east coast shelf are also affected by the Orinoco River regime while offshore is influenced by the Guiana current.

The marine finfish fisheries of Trinidad and Tobago are ‘open-access’ fisheries permitting anyone to fish anywhere at anytime, a facility inconsistent with effective conservation and management of fish stocks. This has led to conflict amongst the various sectors of the fishing industry, and with foreign governments and fishing vessels.

The fisheries sector contributed 0.3% to the GNP in 1996 with estimated annual landings of 7,000 to 10,000 tonnes valued at TT $45m to TT $ 65 million for artisanal fishery. In 1992 shrimp fishery accounted for about 41% of total fish exports and in 1994, shrimp fishery alone was estimated to be worth over

TT $ 21 million.

It is now apparent on anecdotal evidence, and on some reliable scientific evidence, that overfishing may have become a problem. This development has exacerbated the long-standing problems between Trinidad and Tobago and Venezuela concerning fishing in each other's waters. At present there is no active management of stocks of fish. Other factors affecting the marine finfish fishery include lack of surveillance and enforcement capability for existing trawler regulations and other methods; and the significant quantities of by-catch discards particularly in the shrimp trawl fishery.

6.9.3 Other Coastal/Marine Uses

Parts of the nearshore environment in Trinidad have been reclaimed at different times over the past two centuries in and around the capital city. As noted earlier there is no natural deep water adjacent to large population centres and it has been necessary to construct deep water harbours over the years. Some of these have been by dredging works, as at Port of Spain, Point Lisas and Scarborough, and others by jetty to deep water as at Pointe-a-Pierre, Brighton and Point Fortin. Dredged harbours in the Gulf of Paria require periodic dredging owing to continued heavy sedimentation. Minor land reclamations have been a regular feature of coastal development in the Gulf of Paria. These have been associated with harbour and waterfront development, but more recently with housing development, as at Westmoorings and Cocorite.

The marine environment is used regularly in inter-island transport of freight and people, as well as between land-based facilities and offshore oil and gas wells.

One of the most difficult activities to quantify involving use of the marine environment is its use in recreation.

6.10 Effects of Human Settlement and Economic Development

Domestic wastewater management, referred to elsewhere in this report, continues to be a serious and chronic problem. Discharged wastewater finds its way into the marine environment where it can have negative public health effects, largely through its bacterial content. Solid wastes are managed by sanitary land filling with minimal recycling. There is a serious potential problem at the Beetham dump, situated close to the sea where seepage may be transported to the coast via the adjoining wetland. There is at present no toxic waste disposal site in the country and any toxic waste irresponsibly dumped on land is likely to find its way into the sea, via runoff, where it may have adverse effects on marine biota.

Agricultural and industrial pollution are constant features of the economic development of the country. In the first half of the century agricultural pollution was largely associated with the sugar industry and the main areas affected were the Caroni and Cipero rivers, coastal mangroves and the nearshore environment. More recently there has been indirect evidence of the buildup of industrial pollution pressures associated with a wide range of industrial activities, ranging from the petrochemical industry to light manufacturing. The appearance of lesions, deformities and tumours in marine fish, and dieback of coral and seagrass communities in the Gulf of Paria may be evidence of the effect of these pollutants on the biota.

7.0 AIR AND NOISE

7.1 Introduction

Air and noise pollution is significant in most areas of Trinidad and Tobago especially dominated by the built environment, particularly industry, transport and housing especially along the western coast and foothills of the northern range of Trinidad. Recent studies have shown that in Trinidad and Tobago carbon monoxide, nitrogen oxides and suspended particles are large contributors to air pollution. Vehicle emissions are a major contributor of nitrogen oxides. Seasonally across most of the country, there may be air pollution problems associated with bush fires and the sugar cane harvest in the dry season or with upper atmospheric transport of dust from Africa, commonly referred to as Sahara dust. Various negative effects on human health and well being and on the natural environment have become evident within recent times.

There are wider issues of atmospheric pollution which potentially impact on Trinidad and Tobago. These are the production of green house gases particularly carbon dioxide production and ozone depleting substances and their possible effect on global warming and sea level rise. The former continues to be a highly contentious issue as few of the G7 countries have met the targets set at the 1992 Rio summit on the environment under the Framework Convention on Climate Change to which Trinidad and Tobago is a signatory. The international treaty on reduction of the use of ozone depleting substances, the Montreal Protocol on Substances that Deplete the Ozone Layer, to which Trinidad and Tobago is also a signatory, has on recent evidence, led to a measurable repair to the ozone layer over Antarctica.

7.2 Air pollution

Air pollution problems are varied and may involve gases, aerosols and particulates, some of which may be inert and innocuous and others irritating or toxic. In addition to nitrogen oxides and carbon monoxide, these include carbon dioxide, ammonia, volatile organic compounds (a wide range of solvents), chlorine and lead, as well as limestone and other quarry dust, and noxious odours. Some air

pollution problems may be acute and of short duration, while others may be persistent. There are special air pollution problems associated with both heavy and light industry. Total air pollution loadings for the past five years demonstrate an increase by approximately 9% each year (Figure 7-1) with a 3% decrease in 1993. There was an estimated 40% increase in 1995.

FIGURE 7-1

Motor vehicle ownership is about one vehicle per six persons and the majority are older than five years. Leaded gasoline and high sulphur diesel are the principal energy sources used for motor transport. Use of such fuels coupled with poor maintenance of vehicles contribute to serious atmospheric and roadside air pollution. The problem of motor vehicle pollution while widespread along highways, is particularly acute along the Eastern Main Road and the Priority Bus Route, which pass through densely populated settlements, and in the heavily travelled centres of Port of Spain, San Fernando, Arima, Chaguanas and other commercial areas of smaller towns. The principal contaminants are particulate lead, nitrogen oxides, sulphur dioxide, unburned fuel, burnt lubricating oil

and soot. A very recent study of air quality at major road junctions has indicated unacceptable levels of carbon monoxide, hydrogen sulphide, benzene and toluene during the morning rush hour.

There are numerous and varied point sources of air pollution. Heavy industry involved in production of energy, steel and petrochemicals is centered at Point Lisas and operations there, although managed to minimize air pollution, produce the full range of pollutants. Accidental spillages of ammonia have in the past caused human fatality. Power generation there and at other centres in Port of Spain and Penal also contribute to the annual air pollution load.

While concentration of heavy industry in one locality makes it more readily practicable to manage air pollution, dispersed location of light manufacturing and service industries through industrial estates and residential centres presents a very difficult problem. The problem is extremely serious as light manufacturing and services use a wide range of volatile organic compounds and toxic gases such as chlorine. There have in the recent past been spillages of both gas chlorine and sulphur dioxide in residential areas, fortunately without human fatality.

7.3 Impacts of Air Pollution on Human Health and the Environment.

7.3.1 Toxic Air Contaminants

Toxic air contaminants are hazardous to human health, plants and animals and tend to persist in the environment for long periods of time. They are released from a variety of sources and processes and comprise a large number of compounds including heavy metals (lead, mercury), respirable mineral fibres (e.g. asbestos), toxic inorganic chemicals (e.g. chlorine), hazardous volatile organic compounds (e.g. benzene) and halogenated organic compounds (e.g. dioxins). Unfortunately, all of these classes of toxins are present within the atmosphere of Trinidad and Tobago.

Major sources of air-borne toxins in Trinidad identified in studies undertaken during 1995 and 1996 include large point sources such as fossil-fuelled power and other industrial plants involved either in smelting or manufacturing operations. These are located mainly in central and south Trinidad and include plants manufacturing iron and steel, ammonia, urea, methanol, ammonium sulphate, and sulphuric acid; and also include operations of asphalt plants and petroleum refineries. Small diverse sources are pesticide operations, motor vehicles, dry-cleaning facilities and spray painting operations.

Certain persistent toxic substances accumulate over several generations in living organisms and have been associated with damage to the immune system of humans. Dysfunction, reproductive defects, developmental and neuro-behavioural abnormalities and many cancers may also be the result of exposure to these substances.

Pesticide emissions from excessive usage directly affect the agricultural communities using them and settlements located downwind of these communities. Risks to human health and safety also result from inappropriate treatment of exhaust from the numerous spray painting operations in the furniture and car refurbishing industries throughout both islands and from dry cleaning establishments. These activities discharge heavy loads of toxins into the atmosphere on a daily basis.

7.3.2 Common (Prevalent) Air Contaminants.

A number of air contaminants are prevalent which cause or increase the incidence of respiratory diseases. These gases do not persist in the atmosphere as do the toxic air contaminants but, because of the volumes discharged periodically into the environment during some industrial, agricultural or manufacturing processes, elevated levels have been known to persist in areas of Trinidad.

The following air contaminants are of special concern to Trinidad and Tobago:

Sulphur dioxide (SO2), a pungent, colourless gas over 90% of which is generated from the combustion and refining of oil and gas in Trinidad, increases the incidence of coughs, colds, asthma, bronchitis, emphysema, and other respiratory diseases. Sulphur dioxide has also been identified as a contributor to non-respiratory diseases such as skin allergies and reproductive problems. Although persons living in areas of Central and South Trinidad around plants of the oil and gas industry have reported appreciable reductions in the smell of SO2 and other emissions into their environments over the past 10-15 years, actual data indicates that the discharge load into the atmosphere has increased significantly between 1991 and 1995.

Carbon monoxide (CO), a colourless, odourless, highly poisonous gas produced by the burning of substances containing carbon is mainly generated from motor vehicles, forest and bush fires and industrial activity. High levels of CO can impair perception and thinking, slow reflexes and result in unconsciousness and death. Growth and mental development of the foetus can be threatened if it is inhaled by pregnant women. Studies have shown a ten fold increase in CO emissions in Trinidad and Tobago between 1991 and 1995 attributable to the burning of agricultural and forest lands which are responsible for 90% of the air pollution loads in the agriculture, forestry and fishing sector in the country. Petroleum refining accounts for 68% of the load in the manufacturing sector, while iron and steel accounts for 26% and fertilizer manufacturing 6% in that same sector. Electricity generation also contributes significantly to atmospheric pollution in the country emitting over 4,800 tonnes per year of CO.

Oxides of Nitrogen (NOx), emitted principally from fuel combustion in internal combustion engines, industrial boilers, electricity utility boilers and engines, and other miscellaneous equipment contribute to health problems, acid rain formation and haze. Agricultural and forest fires and charcoal production also contribute significant loads of this pollutant in Trinidad and Tobago. Within the manufacturing sector, fertilizer production accounts for 69% of pollutants emitted, cement production 15% and petroleum refining 12%. Electricity generation produces approximately 17,000 tonnes per year of nitrous oxides into the country's atmosphere.

Volatile Organic Compounds (VOCs), consists of a large and diverse group of substances which evaporate into the atmosphere at room temperature and are generally used as solvents in the formulation or manufacturing of consumer products. These have been linked to a wide range of health concerns. Because of the widespread use of solvents in the home, in industry and in the business and commercial sectors, an assumption can be made that overall levels of VOCs in the immediate human environment in homes, offices and other spaces in Trinidad and Tobago may be at unacceptably dangerous levels to citizens health and well-being. VOCs are part of almost all materials and products, ranging from construction materials, furnishings, combustion fuels and pesticides, to hundreds of everyday consumer products such as deodorants, paints, lacquers, polishes, waxes, nail polish etc.

VOCs contribute to the formation of ground-level ozone and acidic compounds in the atmosphere. Data available for Trinidad and Tobago shows that over 21% of air pollution loads come from the use of consumer solvents. In the manufacturing sector, fertilizer production accounts for 65% of air pollution loads and petroleum refining 21%. Electricity generation also produces over 1,755 tonnes per year into the country's atmosphere. Increases in the motor vehicle fuel consumption levels have resulted in increased levels of VOCs to the atmosphere from storage tanks and from the operations of service stations throughout both islands. From 1991 to 1995, emissions of VOCs have increased from 2,757 tonnes per year to 3,179 tonnes per year - an increase of 15%.

Particulates consisting of solid and liquid particles, which remain suspended in air, can reduce visibility and cause respiratory health problems by imbedding themselves in the most sensitive parts of human lungs, the alveoli. Total suspended particulates include smoke, fumes, dust, and fly ash ranging in size from 0.1 to 100.0 micrometres and major sources in Trinidad relate to transportation, mining operations, thermal power generation, deforestation and processing of ores.

In recent years, the combination of smoke from forest fires, domestic waste fires and open burning of waste at disposal sites during the dry season, and Sahara dust, has magnified the

negative impacts on health and environmental aesthetics, particularly of atmospheric visibility. Factory emissions have also been sources of concern in residential areas bordering industrial developments eg. Diamond Vale, Macoya, Point Lisas and O’mera Industrial Estates. Certain organic and heavy metal particulate matter can increase the risk of cancer while lead can affect the circulatory, reproductive and nervous system. It may also impair hearing in children. Particles of flaking paint or masonry from weather worn buildings and other construction sites throughout both islands also enter the atmosphere as pollutants.

Quarrying of stone, sand and clay in Trinidad and Tobago has also been a major source of atmospheric contaminants and estimates show a 63% increase between 1991 and 1995 with figures for 1995 of the order of 38,500 tonnes.

Other major emitters of particulate matter in Trinidad and Tobago come from iron and steel manufacturing (37%), cement (21%), grain and feed mills (16%), structural clay products (7%) and petroleum refining (5%). Electricity generation accounts for the production of 504 tonnes per year.

Ground Level Ozone (O3). Ozone is produced naturally from oxygen molecules in the atmosphere and from hydrocarbons from vehicle engine exhausts and industrial processes reacting with nitrogen oxides and volatile organic compounds in the atmosphere. It persists in the environment as ground-level ozone. Ground-level ozone can damage crops, irritate the eyes and the mucous membranes, reduce resistance to diseases, and aggravate asthma and other respiratory ailments. However, in the upper atmosphere it protects life on the earth by absorbing most of the sun's damaging ultraviolet radiation. High ozone concentrations tend to occur under conditions of bright sunlight, high temperature and a stationary air mass. Ground-level ozone concentrations are strongly influenced by meteorology.

7.3.3 Materials and Methods in and around Homes and Workplaces

While it is not the intention of this report to focus on the effects of indoor air quality on human well-being, this cannot be omitted since it is an area of increasing concern in Trinidad and Tobago. As indicated earlier, many of the materials and methods used in

building construction and furnishings, home appliances, cleaning and office supplies, maintenance of air conditioning systems and in various types of office and manufacturing equipment, all contribute varying amounts of pollution in and around homes and workplaces throughout the country. Some are very common locally as are asbestos ceiling tiles and roofing materials. The pervasiveness of these materials is demonstrated hereunder:

o Asbestos - in thermal insulation on pipes, heat lagging linings on boilers, ceiling tiles, and roofing materials;

o Biological Agents - that is fungi, bacteria and viruses from beddings, pets, carpets, furniture, air conditioners, wet and damp ceilings;

o Carbon monoxide and nitrogen oxide - from tobacco smoke, gas stoves and ovens, kerosene burners and nitrogen oxide;

o Formaldehyde - from pressed wood products containing urea, formaldehyde, glues, textiles, tobacco smoke. Significant usage in Trinidad and Tobago of plywood in dwelling houses and for furniture contributes to the discharge of low levels of emissions for prolonged periods of time;

o Lead -from vehicle engine exhaust and lead-based paints; o Ozone - from electrical appliances e.g. photocopiers; o Particulates - from tobacco smoke, house/office dust, Sahara dust; o Pesticides - from lawn and garden products, household pesticides; o Violatile Organic Compounds - from paints, aerosol sprays,

cleaners, disinfectants, wood preservatives, stored fuel, vehicle supplies, tobacco smoke.

Most homes and work environments in Trinidad and Tobago are exposed to varying degrees of these emissions and contaminants. Unfortunately, insufficient data exists for taking regulatory actions where levels have been deemed as unsafe. Regular tests of public buildings in North America have revealed many "sick buildings" and because of the strong enforcement of laws there, owners are compelled to take action in the interest of public health and safety. It can safely be assumed that numerous sick buildings also occur in Trinidad and Tobago but because similar regulatory mechanisms are not yet in place or are not enforced, public welfare is seriously compromised.

Other significant sources of air pollution which have the potential to impact severely upon human health are lead pollution, ozone depleting substances, used increasingly in Trinidad and Tobago as the country becomes more industrialized, and emissions from the transportation sector. Treatment of these issues is included in Appendix Ι Ι .

7.4 Noise pollution

Because noise dissipates rapidly with distance the phenomenon is generally localized. Many will consider noise more nuisance than hazard, a part of modern society, while to others noise is necessary for enjoyment of life. Excessive noise nevertheless may cause stress disorder and permanent hearing loss. Some noise sources may be irregular while others may be continuous if sustained over long periods. Frequencies of the sound causing vibrations vary from the barely audible low frequency sounds through the full range of human hearing and beyond, and sound sources have characteristic spectra of frequencies.

The principal sources of noise include all manner of heavy machinery, aircraft and motor vehicles, carnival, fetes, sporting events, musical and cultural events, and church worship. Power generation in a residential area in Port of Spain, Wrightson Road, is continuous and this coupled with heavy daytime traffic has degraded the amenity quality of this area. Traffic along the Eastern Main Road and the Priority Bus Route has similarly degraded air quality and sound levels. Aircraft noise is mostly a transient phenomenon, except for those living in or working in close proximity to Piarco and Crown Point airports and smaller landing strips for light aircraft. Noise associated with the intermittent or continuous operation of machinery is extremely varied and those at greatest risk are the operators and persons in the immediate vicinity. The Factories Act covers to a limited extent, management of the problem in premises, but the Occupational Health and Safety Bill which is before Parliament, when passed will extend considerable protection to persons working in noisy industrial environments, as well as those in the vicinity.

Cultural expression in the form of carnival, fetes or church service continues to be a major irritant in residential areas, particularly to those not wishing to participate in activities. Such activities while not necessarily causing hearing loss, can cause extreme distress in sensitive individuals. Remedies are available in law under the Summary Offences Act but are seldom employed. Recent amendment to the Dance Halls and Clubs Act have been passed to strengthen management of excessive noise in residential areas. Map 7-1 shows settlement areas in relation to sources of air and noise pollution and Table 7-1 illustrates relative loudness of noise from different sources.

TABLE 7-1

SOUND LEVELS (dB) AND RELATIVE LOUDNESS OF TYPICAL

NOISE SOURCES IN INDOOR AND OUTDOOR ENVIRONMENTS

dB(A) OVERALL LEVEL

COMMUNITY NOISE LEVELS (OUTDOORS)

HOME AND INDUSTRY NOISE LEVELS

SUBJECTIVE LOUDNESS

(RELATIVE TO 70 dB)

120 Uncomfortably loud

Military jet aircraft take-off from aircraft carrier with afterburner at 50ft…130dB

Oxygen torch 121 dB

32 times as loud

110 Turbo-fan aircraft at take-off power at 200ft…118dB

Riveting machine 110dB

16 times as loud

100 Very loud Boeing 707 or DC-8 aircraft at one nautical mile (6080 ft) before landing…106dB

Jet fly over at 1000ft…103dB

Bell J-2A helicopter at 100 ft…100dB

8 times as loud

90 Boeing 737 or DC-9 aircraft at one nautical mile (6080 ft) before landing …97dB

Power mower…90dB

Motorcycle

Newspaper press 97dB

4 times as loud

(25ft). 90 dB

dB(A) OVERALL LEVEL

COMMUNITY NOISE LEVELS (OUTDOORS)

HOME AND INDUSTRY NOISE LEVELS

SUBJECTIVE LOUDNESS

(RELATIVE TO 70 dB)

80 Car wash at 20ft…89dB

Propeller plane fly over at 1000ft…88dB

Diesel truck 40 mph at 50 ft…84dB

Diesel train 45 mph at 100ft…83dB

70 Moderately loud

High urban ambient sound…80dB

Passenger car 65mph at 25ft…77dB

Freeway at 50 ft from

Living room music…76dB

Radio or TV audio. Vacuum cleaner…70dB

70dB(A)

pavement edge…76dB

60 Airconditioning unit at 100ft…60dB

Cash register at 10ft…65-70 dB

Electric typewriter at 10 ft…64dB

Dishwasher (rinse cycle) 10ft…60dB

Conversation…60dB

½ as loud

50 Quiet Large transformers at 100ft…50dB

¼ as loud

40 Bird calls…44dB

Lowest limit of urban ambient sound…44dB

10 Just audible

7.5 State of Knowledge

Generally, information on air and noise pollution in Trinidad and Tobago has been obtained from occasional surveys done in response to specific or urgent problems. Although some reliable and systematic data are collected on specific parameters by agencies such as the Water Resources Agency of WASA and the Meteorological Services Division, basic data on a wider range of parameters need to be collected consistently and routinely at all major sites that are or are likely to be sources of pollution, and at non-point sources within the ambient environment.

7.6 Management Strategies.

Although there are many uncertainties in determining the state of the environment as it relates to air and noise quality in Trinidad and Tobago, it is evident that development and the pressures of urban growth are resulting in increasing stress on human health and the environment. The quality of the environment is unlikely to be sustained under current management practices. Strategies for monitoring air and noise pollution and for mitigating their impacts on the environment are varied. The final choice of methodology for Trinidad and Tobago would have to be determined and influenced by financial and human resource constraints.

Current management practices must be changed to facilitate routine monitoring of the condition of ecosystems and to develop clear objectives for anticipating the environmental stresses created by growth and development. There is a need to adopt a rational strategy for sustainable development which explicitly recognizes the interdependencies and trade-offs between development and long-term environmental sustainability. This approach is particularly germane to addressing the range of national development activities which is likely to exacerbate the already serious conditions related to air and noise pollution in the country.

8.0 BIOLOGICAL DIVERSITY

8.1 Introduction

Unlike the Caribbean islands to the north which are mostly volcanic and arising from deep water, Trinidad and Tobago is situated on the South American continental shelf and in close proximity to the mainland. The Northern Range is an extension of the Coast Range

of Venezuela and is part of the eastern branch of the Andean Mountain System. Both islands are directly influenced by seasonal discharge from South American rivers, particularly the Orinoco River, but the influence is a graded one and more pronounced in Trinidad, especially in the southwest and the Gulf of Paria. During the months of July to December, discharge of freshwater from the Orinoco delta decreases the salinity of coastal waters and increases the quantities of sediments. As a consequence, there is a distinct gradation of communities and ecosystems from freshwater to oceanic extending from Icacos in southwest Trinidad to St. Giles in the northeast of Tobago.

Published knowledge of the biota of Trinidad and Tobago is extensive and dates back over 150 years. The flora is particularly well documented. The Flora of Trinidad and Tobago has been serially published by Government since the early 1920s. The flora is now almost completely published and only the grasses and ferns remain to be published. Attention is yet to be paid to lower plants, marine fungi and some groups of marine algae. Some groups of animals, for example the vertebrates, are particularly well documented but larger groups such as insects are only partially documented and arachnids very poorly documented. Documentation of marine groups is more recent and consequently less comprehensive, but marine algae and some key invertebrate groups are comparatively well known.

While there is some knowledge of many individual taxonomic groups and some communities, detailed studies on specific ecosystems are few. In the terrestrial environment there have been comprehensive evaluations of moor forests, the Aripo savannahs, palm forests, major wetlands and a few stream systems. In the marine environment there have been fewer studies and these include some coral reefs in Tobago and Trinidad and sheltered mud bottom areas in the Gulf of Paria.

8.2 Species Numbers and Diversity

Trinidad and Tobago's biota is rich in numbers of species, is typically South American and mainly a relict of what was present when the separation of the islands from the mainland took place. In addition, there are many exotic plant species as well as a few exotic animal species which are now well established parts of the biota. Some species which are considered indigenous may in fact be exotics, introduced by the first settlers, the Amerindians. A number of species, both plant and animal may be locally rare. It is

only possible to make crude overall estimates of numbers of species falling somewhere between 10,000 and 15,000.

Differences in size between Trinidad and Tobago, as well as differences in topography, soil and climate, account for the greater relative richness of biota and ecosystems in Trinidad. Although at one time several species were listed as being island endemic species, more recent research has demonstrated that many of these are in fact also found on the adjacent mainland. Current knowledge of evolutionary processes also suggests that the time elapsing since separation is insufficient to permit formation of new species. There is some evidence of the presence of geographical races.

8.3 Flora

The flora of Trinidad and Tobago consists of approximately 2,500 species in about 175 families. In terms of numbers of species the largest families are the ferns and their allies, with approximately 310 species; the grasses, legumes and orchids, each with about 200 species; and the sedges, madders, melastomes, composites and euphorbs each with about 90 species. Table 8-1 shows some of the larger plant families. There is strong circumstantial evidence of continuing natural colonization, and consequent enrichment of the indigenous biota, of the south western peninsula of Trinidad from the Orinoco Delta. Both plant and animal species colonists have been recorded on the south coast adjacent to the major river discharges. Natural movement of species across barriers is of particular interest to biogeographers and evolutionary biologists.

TABLE 8-1

LARGE PLANT FAMILIES

Large families in terms of species numbers in Trinidad and Tobago (approximately 55% of the total number of vascular plants):

FAMILY GENERA SPECIES

Ferns & allies 66 (51)* 310 (214)*

Grasses 74 214

Legumes 75 202

Orchids 68 190

Sedges 22 111

Rubiaceae 48 97

Melastomes 22 95

Composites 45 86

Euphorbs 27 82

* Ferns only

In addition to the native flora there are many exotic species in Trinidad and Tobago. There is some uncertainty as to actual numbers but many tree crop and timber species may be found in highly perturbed areas. There are also numerous exotic grass and various ornamental species, some of which are to be found throughout the country, even in remote areas. The total number of exotic species may be about 300.

8.3.1 Terrestrial Plant Communities

Although the process of settlement and social development of Trinidad and Tobago has severely altered native plant communities and their associated biota, the process has not been as devastating as in other islands to the north of Trinidad and Tobago. In Trinidad and Tobago it is still possible to see the full range of plant communities existing from pre-Columbian times. This is not to say that these are not under constant pressure. Indeed, there has been significant reduction and perturbation of areas of natural vegetation during the past five decades.

Several distinct communities are recognized. At lower elevations there are evergreen seasonal forests typical of high rainfall areas; semi evergreen seasonal forests found in average rainfall; deciduous seasonal forests in low rainfall areas and dry evergreen forests which are coastal adaptations to high winds and salt spray. At higher elevations may be found montane forest types and cloud forest or elfin woodland. At low elevations and where there is impeded drainage there are a range of forest and plant communities including swamp forest, palm forest, marsh forest, savannah, herbaceous swamp and mangroves typical of saline conditions (Map 8 - 1).

8.3.2 Marine Plant Communities

In the marine environment the principal plant communities to be found are the phytoplankton, seagrass beds and marine algal communities. Being confined to the water column which is in constant flow through the area, phytoplankton communities are generally independent of the land masses. Sea grass communities are usually found in shallow sheltered waters on firm sandy bottoms. Sessile algal communities are to be found mainly on hard substratum often in exposed high energy conditions, and many species are adapted to depths greater than those associated with sea grasses. Sessile algal communities often include sponges and corals.

8.3.3 Exploitation of Flora

Only a comparatively small number of native plant species are directly exploited. Approximately 50 timber species are exploited but only about a fifth of these are Class I species, as declared in the schedule to the Forests Act (Table 8 - 2).

TABLE 8-2

TIMBER SPECIES

Local Name Species Family

CLASS 1

Acoma

Balata

Balsam

Cedar

Cypre

Locust

Mahogany*

Poui

Roble

Samaan*

Teak*

CLASS 11

Angelin

Crappo

Fiddlewood

Fustic

Galba

Guatacare

Laurier black

Laurier canelle

Sideroxylon quadriloculare

Manilkara bidentate

Copaifera officinalis

Cedrela odorata

Cordia alliodora

Hymenaea courbaril

Swietenia macrophylla

Tabebuia sp.

Platymiscium trinitatis

Samanea saman

Tectona grandis

Andira inermis

Carapa guianensis

Vitex spp.

Chlorophora tinctoria

Calophyllum lucidum

Eschweilera subglandulosa

Sapotaceae

Sapoteceae

Leguminosae

Meliaceae

Boraginaceae

Leguminosae

Meliaceae

Bignoniaceae

Leguminosae

Leguminosae

Verbenaceae

Leguminosae

Meliaceae

Verbenaceae

Moraceae

Guttiferae

Lecythidaceae

Lauraceae

Laurier cypre

Mora

Olivier White

Pine*

Podocarp

Purpleheart

Serrette

Tapana

Toporite

Yoke

Nectandra mortiniansis

Aniba panurensis

Ocotea oblonga

Mora excelsa

Terminalia amazonia

Pinus caribaea

Podocarpus coriaceus

Peltogyne porphyrocardia

Bursonima coriacea

Hieronyma caribaea

Hernandia sorora

Astronium obliquum

Lauraceae

Lauraceae

Leguminosae

Combretaceae

Pinaceae

Coniferae

Leguminosae

Malpighiaceae

Euphorbiaceae

Hernandiaceae

Anacardiaceae

Three exotic species, teak, mahogany and Caribbean pine have become important elements of the local timber industry, with teak and pine forming relatively extensive monocultures. Pine has generally been planted to restore quick cover to areas burnt by wild fires. Teak plantations have generated revenue mainly from the sale of thinnings and mature logs. The former practice of removing natural forests to create teak plantations has been discontinued.

Plants are exploited for a variety of other uses. Tree ferns, for example, are harvested for use as orchid growing medium, while different palm stems and other tree species are employed in basket making. Some species are harvested as foliage species, particularly aroids and ground pines. Others are used in gardens as ornamentals. One species, Ryania, is harvested and exported for production of an insecticide, Ryanex. There are few species of global importance in horticulture, the Double Chaconia (Warszewiczia coccinea), a mutant form originating in Trinidad, being significant. Some bee orchids and bromeliads are exported. Many native species are employed in infusions, both of leaves and bark for folk remedies, some of these being in fact dangerous. Mangrove wood is no longer used as fuel but its bark is still

employed in tanning. Except for a few fruit and a marine alga, very few native species are used as food (Table 8 - 3).

TABLE 8-3

SOME NON-TIMBER EXPLOITED PLANT SPECIES

USE LOCAL NAME SPECIES

Beverage making Sea moss Gracilaria spp.

Orchid growing material Tree fern Cyathea spp.

Cnemidaria spp.

Stem used in basket making

Tirite Ischnosiphon arouma

Petiole used in basket making

Moriche Mauritia flexuosa

Basket making - Various Bignoniaceae and Cycanthaceae

Horticulture, export Orchids e.g.

Butterfly

Cedros bee

Yellow bee

Oncidium papilio

Oncidium lanceanum

Oncidium ampliatum

Stems exported for production of Ryanex (insecticide)

Ryania Ryania speciosa

Aphrodisiac Bois bande (bark) Parinari campestris

Roupala montana

Richeria grandis

Tanning of leather Mangrove (bark) Rhizophora mangle

During the past two decades there has been significant expansion of the exploitation of natural forest communities in ecotourism and scientific study in the Northern Range, and a trend in the past few years to use other areas.

8.4 Fauna

Published knowledge of the fauna of Trinidad and Tobago is extensive and certainly more voluminous than that of the flora. This is simply because of the fact that animal species generally outnumber plant species in most ecosystems. One group of terrestrial animals, the vertebrates, which is smaller in number than either insects or arachnids, numbers almost 600 species and if to this is added marine fish, reptiles and mammals, the total number exceeds 1,000 species. Unlike the case of the flora, publication of accounts of faunal groups is widely scattered, of uneven quality and unsupported by direct Government action. In addition, there are immense gaps in knowledge, with some groups being virtually ignored.

There are about 45 freshwater fish, 30 amphibians, 85 reptiles, slightly more than 400 birds and 95 mammals recorded for Trinidad. The numbers of species recorded for Tobago is significantly smaller owing to smaller size of that island, while there are some Antillean species found there not found in Trinidad. Of the bird records, many are regular migrants, several are dubious or rare sightings but as many as 250 species actually breed in Trinidad and Tobago.

Of the terrestrial invertebrates the insects are best known. The well documented groups include butterflies, doctor butterflies,

dragonflies, caddis flies, water bugs, termites, ants and wasps, mosquitoes, sandflies, some beetles and bugs. It is quite impossible to estimate numbers but the butterflies, doctor butterflies and moths alone probably exceed 1,500 species. In contrast, arachnids and roundworms which are numerous in many terrestrial systems are extremely poorly documented. The rest of the terrestrial fauna is equally poorly known but includes some flatworms, roundworms, earthworms, molluscs, crustaceans and millipedes. On the basis of what is known from better documented areas in the neotropics it is possible to project a total terrestrial fauna of something in excess of 10,000 species.

The coastal waters of Trinidad and Tobago support a range of fish species both pelagic and demersal finfish as well as shellfish. In addition, sea turtle nesting populations are found on several beaches in Trinidad and a few in Tobago. The marine fauna is not particularly well documented. There has been no recent treatment of the marine fishes of Trinidad although much can be extrapolated from reports on the icthyofauna of the Caribbean region. The invertebrate groups documented include sponges, corals, horny corals, marine worms, some gastropods, crabs, other crustaceans and obscure minor groups. Again, as in the case of the fishes, much information can be assumed from the literature on the wider Caribbean biogeographical province to assist in local management activities and to determine research priorities.

8.4.1 Faunal Distribution

Although much of the terrestrial fauna, especially the invertebrate microfauna, is widely distributed throughout the country, the vertebrate macrofauna displays preferences for certain well defined habitats. The avifauna, for example, displays distinctive assemblages associated with elevated forests, savannas, cleared areas, human habitation, public dumps, tree crops, wetlands, coastal areas and the open sea. Similarly, freshwater and estuarine fishes, amphibians and reptiles display assemblages. The bulk of the mammalian fauna consists of bats and rodents, the distribution of the former being determined by roosting and feeding habits and the latter by dietary and habitat requirements. The game mammals are mostly creatures of the forests, but the agouti may be seen in cleared and built areas. Although there are several caves in the country, especially in the northern and central ranges of Trinidad, most of the cave biota consists of species associated with the adjacent forest and there are no obligate cave species, except for the blind cave fish of the Oropouche cave.

Distinctive marine communities are to be found associated with substratum types. Most of the sea bottom of the waters under the jurisdiction of the country consists of mud. Nearshore there may be sandy bottom, beaches, rocky shores and coral and algal beds. Although there is some variability, community type may reflect other factors such as illumination, energy and water quality. Coral reefs generally display greatest diversity. Many fish species may be found common to more than one type of sea bottom. Distinctive communities are also to be found in the water column.

8.4.2 Exploitation of Fauna

Relatively small numbers of the fauna are directly exploited as food species. Many marine species are important food species, as for example several fish, shrimp, crabs and molluscs. Some freshwater fish, molluscs and crustaceans are also exploited as food. Some mammals, bird species, and the common iguana are hunted but do not constitute a major food source. These include deer, lappe, tatu and agouti, manicou, wild hog and ducks and "plovers". Many mammal and bird species, even protected species, are opportunistically killed on the hunt.

Many vertebrate species are utilized other than as food as evidenced by the thriving trade in birds, particularly finches. Indeed some species of finch have become extremely rare because of over-collection. Also, several bat species are now routinely employed as laboratory animals in the United States and are sourced from Trinidad. Caimans are harvested for manufacture of curios or kept as pets (Table 8 - 4).

TABLE 8-4

SOME EXPLOITED ANIMAL SPECIES

USE LOCAL NAME SPECIES

Laboratory animals, reproductive biology research

Bats

Fish bat

Vampire

Carollia perspicillata

Molossus ater

Molossus major

Noctilio leporinus

Desmodus rotundus

Recreation (hunting) Wild meat Several species

Pet trade Song birds (finches) Sporophila imtermedia

Sporophila nigricolli

Sporophila minuta

Oryzoborus crassirostris

Oryzoborus angolensis

Pet trade Parrot Pionus menstrus

Amazona amazonica

Curios, meat Alligator Caiman crocodilus

Meat, pet trade Iguana, guana Iguana iguana

8.5 Benthic communities

The shallow water sublittoral of Trinidad and Tobago displays the full range of benthic communities to be found in the Caribbean biogeographical province. The distribution of these community

types is determined partly by local bathymetry and substratum type, but the dominant influences are determined by the effects of the Orinoco River on salinity and turbidity. There are varied coral reef communities in Tobago where the effects of the Orinoco River are less severe. Along the eastern part of the Northern Range and offshore, east of the East Coast, there are also hard bottom coral and algal communities. In deeper water, again as may be expected, the sea bottom is mainly mud.

8.6 Key and Charismatic Species and Ecosystems

Although there are probably few island endemic species in Trinidad and Tobago, there are several key and charismatic species of note. Key species often give advanced warning of problems which may adversely affect human society. Dying monkeys indicate an outbreak of sylvan yellow fever which may quickly move to urban areas. The absence of gill breathing freshwater fishes in a stream gives a warning of anoxia resulting from organic pollution. Many species of higher vertebrates have charismatic appeal and their conservation can be highly effective tools in giving focus to environmental education and awareness from very early ages. Manatees, ocelots, marine turtles, some butterflies such as the emperor, showy orchids such as the Cedros bee and the butterfly orchid, and tree ferns are typically charismatic. Common species such as humming birds and the scarlet ibis may also have charismatic appeal, simply for their beauty and display. Species such as the leatherback turtle have international charismatic appeal (Table 8-5).

TABLE 8-5 - KEY AND CHARISMATIC SPECIES

COMMON NAME SCIENTIFIC NAME FEATURES

Ocelot Felis pardalis c Forests – rare

Manatee Trichecus manatus c Nariva – small breeding herd

Howler monkey Aloutta seniculus k Sentinel species for yellow

fever virus

Otter Lutra longicaudis c Rivers in north east Trinidad – rare

Scarlet ibis Eudocimus ruber c The national bird

Humming birds {Several species} c Flight, feeding and colours

Bay headed tanager Tanagra gyrola c High altitude montane forest

Speckled tanager Tanagra guttata c High altitude montane forest

Swallow tanager Tersina viridis c High altitude montane forest

Red-bellied macaw Ara manilata k Nariva swamp – palm forest

Pawi Pipile pipile k+c Island race of piping guan – forests – rare

Diablotin or Oilbird Streatornis caripensis

c+k Cave roosting – Aripo, Oropouche and a few other caves in the Northern Range

Red-billed tropic bird Phaeton aethereus c Breeding colony in Little Tobago & St. Giles

Mot mot Momotus momota c Common in Tobago but unusual in Trinidad

Toucan Rhamphastos vitellinus

c Forest – usual form

Anaconda (Houilla) Euectes murinus k Nariva – largest snake in western hemisphere

Mapipire zanana Lachesis muta k Largest pit viper – rare

Leatherback turtle Dermochelys coriacea

c Largest marine turtle – significant breeding sites in north east Trinidad

Surinam toad Pipa pipa Only obligate water dwelling frog – direct development of eggs in brood pouches

Golden tree frog Phyllodytes auratus k+c El Tucuche possibly island

endemic species

Mountain chicken Leptodactylus bolivianus

k Mayaro forest – largest frog in Trinidad

Freshwater sardines {Several genera/ species}

k Gill breathing and highly sensitive to aquatic pollution

Cascadu Hoplosternum littorale

c Edible – deeply ingrained in folklore

Blind cave fish Rhamdia quelen k Eyeless form of river catfish, Oropouche cave

Emperor butterfly Morpho peleides c Size, habits and beauty

COMMON NAME SCIENTIFIC NAME FEATURES

Black coral Antipathes atlantica k Deep water – used in jewellery

Tree fern Cyathea spp. Cnemidaria spp.

k+c Largest ferns in Trinidad and Tobago – used in orchid culture – over collected.

Wild pine Aechmea dichlamydea

Vriesia splendens Guzmania lingulata

c Epiphytic – forests – of horticultural interest because of floral form and beauty.

Ground orchids Cyrtopodium parviflorum Cyrtopodium punctatum

Pogonia rosea

k+c Showy but rare orchids – much over-collected.

Cedros bee Oncidium lanceanum

c Cedros – showy fragrant orchid

Butterfly orchid Oncidium papilio c Forests – unusual floral form and flowering habits

Bladderwort Utricularia spp. k Aripo savannah – carnivorous

Sundew Drosera capillaris k Aripo savannah – insectivorous

Double Chaconia Warszewiczia cocinea

CV David Au Young

c Island mutant form

Cedros balisier Heliconia marginata k Wetlands – Cedros area

Mora Mora excelsa k+c Hardwood occurring in pure stands in north east Trinidad

c = Charismatic

k = Key

Trinidad and Tobago enjoys a wide range of ecosystems typical of location and physical characteristics. Some of these systems are key in the same sense as key species in that they have charismatic appeal, while others are atypical or much reduced. Coral reefs and wetlands are both key charismatic, while others such as cloud forest, savannah or river gorge are charismatic because they are unusual (Table 8-6).

TABLE 8-6 - KEY ECOSYSTEMS

ECOSYSTEM CHARACTERISTICS LOCATION

Cloud forest High rainfall/humidity/cloud – Stunted trees – many mosses and lichens

Summit of El Tucuche and Cerro del Aripo

Xerophytic forests Low rainfall/extended dry season/deciduous trees and cacti

Chacachacare

Herbaceous swamp Semipermanent inundation – specialized flora

Nariva Swamp

Savannah Poor drainage/nutrient poor – specialized flora

Aripo – The Aripo savannah is the only remaining undisturbed savannah in Trinidad

Mangrove swamp Tidally inundated – specialized and much reduced flora

Caroni, South Oropouche, Los Blanquizales, North Oropouche

River gorge Water worn channels in bedrock

Guanapo gorge, Madamas gorge

Fringing coral reefs Emergent reef crest with lagoon

Buccoo, Salybia

Offshore islands Isolated with breeding sea birds

St. Giles, Little Tobago, Soldado

Rocky shore Resistant bedrock exposed by strong wave and current action – algal covered with many herbivores

North eastern Trinidad, Bocas area, Tobago.

Caves Cavities in rocky strata – total darkness – bats and invertebrates

Aripo, Oropouche, Tamana.

8.7 Effects of Development on Biological Diversity.

Human population growth has had and continues to have profound effects on the natural environment. In addition to the simple need for space for settlement, industrialization and agriculture which reduce areas of natural environment, the principal causal factors include:

(i) squatting;

(ii) shifting cultivation;

(iii) recurrent fires;

(iv) illegal hunting and unrealistic game laws;

(v) irregular forestry practices and illegal logging;

(vi) un-planned building and quarrying;

(vii) illegal dumping and disposal of wastes; and

(viii) irresponsible dumping of toxic materials.

One frequently unappreciated effect of human settlement is collateral development of agricultural and forest ecosystems, some of which have degrees of diversity to rival natural systems and some of which support unusual assemblages of organisms.

Some of these factors have contributed to severe perturbations in the marine environment especially nearshore, in reclamation of coastal sites and establishment of industry. One effect of human population growth is the considerable pressure on marine fish stocks. Available evidence indicates depletion particularly of demersal species, especially croaker, salmon and sharks.

8.8 Management of biological resources

8.8.1 Institutional Issues

8.8.2

Management of the biological resources of the country is through a patchwork of legislation, much of it archaic, and a system in which responsibilities are spread over different agencies. Some protection is given to natural areas through the Forestry Act and the Marine Areas (Preservation and Enhancement) Act. In the former forest reserves, game sanctuaries and prohibited areas are designated and terms and conditions for exploitation of timber and wild fauna defined. In the latter, Buccoo Marine Park is delimited. Wildlife is given some degree of protection under the Conservation of Wildlife Act. The Chaguaramas Development Act gives to the Chaguaramas Development Authority powers to prohibit hunting within the area. Fish resources are given some protection under the Fisheries Act.

A chronic problem is the general and widely accepted lack of enforcement of legislation, a phenomenon not confined to conservation of biological diversity. Squatting and illegal logging in forest reserves continue while hunting takes place in and out of hunting seasons in wildlife sanctuaries, including Chaguaramas and Bush Bush, and mesh regulations for fishing nets are ignored. In general enforcement capacity is severely limited by lack of human and financial resources. Systematic and focused education on Environment within the school curriculum is limited as are sustained public education and awareness campaigns on environmental issues. Draft legislation on National Parks and Wildlife, and on Fisheries have been prepared recently for public comment before submission to Parliament.

8.8.2 Status of Species

Widespread concern continues to be expressed for the decline in numbers of some species and extinction of others. As natural areas are converted to human settlement and species hunted, it is inevitable that many species will become less common, and this becomes particularly evident in the case of the larger game species which require more space for maintenance of viable populations. Manatee, for example, were previously known in both the south Oropouche and Caroni drainages, but only a small herd remains extant in Nariva. While many species maintain a tenuous existence in Trinidad and Tobago, there are few actual confirmed extinctions. The scarlet macaw and the blue and yellow, both widely distributed in the neotropics are probably now locally extinct. Both species may however have been exotics introduced by Amerindians several millennia ago. Several of the non-game mammals are now evidently confined to remote areas. It is possible also that one species of river catfish may be locally extinct. Several plant species, particularly those requiring special habitats have also become uncommon. On the other hand it must be noted that the biota of Trinidad and Tobago is essentially South American and local extinction of a few species will not be a catastrophic loss to global diversity for wide ranging species. The significance of such extinction will be at the national level where the overall genetic pool

would be reduced and altered and its benefit to the nation eliminated.

The terms ‘at risk’, ‘threatened’, endangered and ‘rare’ adopted from international sources such as the World Conservation Union (IUCN), are now commonly employed in technical reports and the media. What is required is for Trinidad and Tobago to embark on an assessment of the status of its species for more accurate categorization. For example, all marine turtles are considered endangered, yet the hawksbill is common in local waters and not as widely exploited as in the past. In contrast, another reptile, the bushmaster or mapipire zanana, is usually destroyed on sight, as are all snakes. This snake is now rarely seen and must be highly endangered in Trinidad, and is legally listed as vermin.

8.8.3 Data Collection and Information Management

Conservation and management of biological diversity assumes scientific knowledge of the diversity of species, their assemblages and inter-relationships in communities, and the relationship of these to the natural environments supporting them. Scientific study of the biota of Trinidad and Tobago continues to be under-supported and directed largely through individual initiative. Much of the knowledge of the flora has originated from specialists working in metropolitan centres on material collected locally. Much of the knowledge of the fauna has also been determined in this way although some noted contributions have come from resident naturalists. In contrast to the orderly development of the flora over the past seventy years, studies on the fauna have been biased toward vertebrates and insects without a national plan. The recent approval of funds for Trinidad and Tobago to prepare a National Biodiversity Strategy and Action Plan (NBSAP) as part of its implementation of the Convention on Biological Diversity will no doubt improve this situation within the next two years. Hopefully, this will contribute significantly to harmonization and structuring of research programmes on biological diversity in Trinidad and Tobago.

9.0 Imperatives for Action

The earlier chapters of this report demonstrate that the social and economic development processes which have been taking place in Trinidad and Tobago during the past few decades have not been without pronounced negative effects on the natural environment. Accelerated development in the past two decades has extended and intensified many of the negative effects. In the built environment the most striking effects are to be seen in widespread pollution of water and air and are associated with haphazard dumping of solid and toxic wastes, unplanned housing and commercial settlement and development, and mismanaged industrial activity. These have led generally to poor air quality and degradation of the receiving environments of the lower courses of rivers and the nearshore coastal waters.

There has been extensive deforestation in critical watersheds, associated with shifting cultivation, hillside agriculture, inappropriate and illegal logging, and sand and gravel extraction. These activities cause siltation in watercourses and lead to flooding. Experience elsewhere in the developed world has shown that reversal of the effects of degradation invariably costs more then prevention of the degradation. The key problem has been both one of enforcement of law and preventative measures as well as commitment of resources, both financial and human, to solutions to problems.

The preamble to the Environmental Management Act of 1995 states that the Government of Trinidad and Tobago is committed to the goal of sustainable development which seeks to balance protection and maintenance of the natural environment and its resources with economic development for the welfare of present and future generations. The studies on which this report is based have revealed a diverse range of environmental problems, not unlike those experienced elsewhere in both the developed and developing world. The key issue now is development of a national overall strategy for economic and social development which recognizes interdependencies of stable environment and ordered development, at the same time as recognizing the necessity of trade-offs between them.

One desired approach to development of this strategy is to place the negative effects of development in a hierarchical order, reflecting the relative importance of such effects to immediate health and welfare of citizens. Such a hierarchical order clearly leads to assignment of priority. At the same time, if the interdependencies are well understood, issues or problems that might not seem to be directly related to health are readily captured in the strategy net. For example, availability of quality potable water

is clearly vital to health while at the same time, maintenance of major watersheds is essential to production of potable water. It follows naturally that production of potable water meeting the highest standard must necessarily require maintenance of the highest standards of watershed management.

Given the accumulated damage over the past few decades and bearing in mind the importance of funding, one of the most difficult policy decisions will be dedication of resources to the very high cost activities of remediation and protection. It is impossible to make accurate estimates of costs in many cases but one estimate for cleaning up the environmental damage caused by the State- owned oil company Petrotrin and its predecessors was calculated at TT $1 billion over a period of 10 years. At the same time prevention of further damage to the remaining natural areas and watersheds must also be addressed. Some protection of natural environment is already available but the central issue is enforcement and the costs of enforcement. Preventive approaches to protection may become available through sustained public education, raising of public awareness and the active participation of individuals, groups and organisations in addressing environment and development issues. Minimal investment, it must be noted, yields minimal effect.

The several initiatives taken by Government, regarding vehicle emissions, including the phaseout of lead in gasoline must be noted. These however, can only be part of the mix of environmental management tools essential to ensuring the welfare of citizens now and in the future.

The basic studies utilized in the preparation of the report identify specific areas where action is needed to arrest negative effect or which require rehabilitation. The report also identifies the need to obtain basic and additional data and information to facilitate continuing evolution of action–oriented policies, and to permit the country to meet its obligations to its neighbours and the international community. The major needs are:

o adoption of standards for air and water quality, solid waste management, handling and disposal of hazardous and toxic materials and wastes

o adoption of a balanced programme of enforcement of these standards with public education

o establishment of appropriate and well-maintained facilities for the safe treatment and disposal of all types of waste, in particular, sewage and toxic and hazardous waste

o adoption of a programme of incentives (including fiscal) for environmental maintenance and upgrading

o establishment of a comprehensive and coordinated national environmental monitoring system

o initiation of a progressive programme of environmental remediation of areas adversely affected by Petrotrin, Caroni (1975) Limited and major industrial estates

o development and adoption of a comprehensive programme of preventative and rehabilitative measures for watersheds

o establishment and investment in a comprehensive system of parks and protected areas

o development of a structured programme of data collection on biological species and ecosystems to improve the existing body of knowledge

o progressive review and harmonization of environmental legislation

o a legislative programme to produce special legislation necessary for international commitments

Historically, administrations in Trinidad and Tobago have given low priority to environmental issues. Indeed, the State itself has been responsible for much of the environmental degradation and inefficient use of natural resources through its policies and programmes. While it is true that even from colonial times some attempts have been made to regulate physical development and to conserve the natural environment and its renewable resources, allocation of financial and human resources to the tasks has not kept pace with needs. Coupled with this is the deep-seated problem of lack of enforcement of existing legislation. It is therefore imperative that a larger percentage of the core annual budget be utilized for environmental management.

BIBLIOGRAPHY

Caribbean Industrial Research Institute. The State of the Environment Report with Respect to Air and Noise. Trinidad and Tobago: 1997.

Environmental Management Authority. State of the Environment Report. Trinidad and Tobago: 1995.

Institute of Marine Affairs. Environmental Management Authority Environmental Data and Information Project: Physical Oceanography, Water and Sediment Chemistry, Fisheries and Coastal Dynamics. Trinidad and Tobago: 1997

Kairi Consultants Limited. Environmental Management Authority Environmental Project. Land. Trinidad and Tobago: 1997.

Kairi Consultants Limited. Environmental Management Authority Environmental Project. Socio-economics. Trinidad and Tobago: 1997

Kenny, Julian; Comeau, Paul and Katwaru, Leslie Anne. Environmental Management Authority Data and Information Project: A Survey of Biological Diversity, Trinidad and Tobago. Trinidad and Tobago: 1997.

Toppin-Allahar, Christine. Basic Environmental Studies (IDB): Technical Report on Institutional Strengthening and Legal Infrastructure. Trinidad and Tobago: 1992.

Trinidad and Tobago. Ministry of the Environment and National Service. National Report on Environment and Development, Trinidad and Tobago: 1992.

APPENDICES

APPENDIX Ι

SOURCES AND LEVELS OF AQUATIC POLLUTION

Studies carried out over the last two decades on water pollution by several organisations and individuals provide information on the sources and range of pollution in various river systems as described in Tables Ι – A; Ι - B; and Ι - C. Table Ι - D indicates the functional status of sewage treatment plants in Trinidad and Tobago in 1991.

APPENDIX Ι . - A: EXISTING AND POTENTIAL SOURCES OF POLLUTION

IN THE CARONI RIVER BASIN

River Systems Domestic Refuse1

Domestic Sewage 2

Industrial Effluents3

Farm Wastes4

Agricultural Chemicals5

Momuripo v v g v g v g v

San Juan v ei v aegi v aeghi v g v

St. Joseph v ei v aegi v aeghi v g v

Guayapo v ei v egi v gi v g v

Tacarigua v e v egi v ghi v g v

Arouca v v egi v gi v g v

Oropuna v v egi v gi v g v

Mausica v b v bcdegi v bcdefgi v bcdefg v d

Carapo/Manacal v bei v bcdegi v bcdefgi v bcdefg v cd

Arena v - - v g v

Tumpuna v b - - v g v

Arima v b v bcdegi v bcdefghi v bcdefg v

Guanapo v be v beg v h v beg v

El Mamo v b v be v h v beg v

Aripo v b v beg v h v beg v

Cumuto v b v e - v eg v

Madame Espagnole v v g v g v g v

Cunupia v v g v g v g v

Caroni v be v abcdegi v abcdeghi v abcdeg v cdj

• - existing and potential pollution as identified in the literature from field measurements and

observations

- - no confirmed reports

1 - includes garbage, trade refuse and seepages from solid waste disposal sites

2 - includes seepage from cesspools and pit privates

3 - includes quarrying wash waters

4 - includes wastewater from animal processing plant/abattoirs

5 - includes runoff from the use of fertilizers and pesticides

a - Siung-Chang, et al., 1987 b - Wessex Water, 1988 c - CARDI/CARIRI/UWI/WASA, 1979

d - Seaforth and Jones, 1978 e - Gov. of T&T, 1976 f - Millette and Humphreys, 1979

g - Rajkumar et al., 1992 a&b h - Gov. of T&T, 1993 i - Delcan, 1994 j - Sampath, 1982

APPENDIX Ι . - B: PHYSICAL AND BIOLOGICAL RANGES OBTAINED in the caroni river basin

Riverine Stations

Suspended Solids mg/L

Total Dissolved

Solids mg/L Biological

Oxygen Demand mg/L

Salmonella per/100ml

Total Coliforms per/100 ml

Faecal Coliforms per/100ml

San Juan -

-

-

-

-

-

-

49-123a

0.5-11I

-

-

-

e1.2x103-

1.5x104

-

7.0X106

3.0X107

-

-

1.2x104-

9.0x106

St. Joseph -

-

-

-

-

-

-

47-112a

7-60I

-

-

-

e3.2x104-

4.5x105

-

8.0x104-

3.0x107

-

-

5.0x103

1.0x107

Guayapo - - 5-20I - 1.2x104-

2.0x107

8.0x103

3.0x106

Tacarigua - - 1-7I - 0.5x104-

8.0x105

1.0x103-

2.0x105

Arouca - - 8-50I - 9.0x105-

8.0x107

5.0x105-

5.0x106

Oropuna - - 3-30I - 6.0x105-

5.0x107

1.2x104-

4.0x106

Mausica 6-360b

10-22d

-

179-251c

-

-

-

-

143-233

-

7-440

0.5-2.2

-

4.9-19

10-20I

-

-

e6.0x103

-

-

1.7x104

-

3.0x106

-

3.0x105-

5.0x106

3.6x103

-

-

-

1.0x105-

4.0x106

Carapo/ Manacal

-

146-343c

7-60d

3-1879b

-

108-273

-

-

5-7e

6.6-32

0.6-5.0

2-826

0-2.0x103

-

-

-

2.5x105-

2.6x106

-

-

-

-

-

5.1x103

- - - - 5.0x104- -

Tumpuna -

21-29b

110-210e

-

-

3

-

-

-

1.3x103

-

<31

Arima 486-743c

-

76-96d

5-14b

133-155

-

-

-

5.4-9.4

2-7e

0.8-1.3

3-9

-

0-3.0x103

-

-

-

1.4x105-

6.8x105

-

3.4x103

-

-

-

670

Guanapo -

3-80b

-

-

3-5e

2-6

0-5.0x103

-

5.2x105-

8.3x105

1.5x105

-

2.2x103

El Mamo -

5-6b

-

-

6-7e

2-3

0-1.2x104

-

9.7x104-

7.1x105

2.5x104

-

4.6x103

Aripo -

8-26b

-

-

5-9e

1-2

0-2.5x104

-

8.6x104-

6.3x105

1.6x103

-

1.1x103

Cumuto - - 8e 1.3x104 5.0x106 -

Caroni 10-104b

-

510-598c

-

59-274d

-

-

110-300e

125-159

-

-

-

4-10

4-102

7.5-8.4

8-157a

0.1-1.5

1-7I

-

2x103-

3.6x103

-

-

-

3.1x104

3.9x105

500-8.9x106

-

-

-

1.2x105-

1.0x106

2.4x103-

2.5x105

-

-

-

-

1.0x103-5x104

a - Siung-Chang, et al., 1987 b - Wessex Water, 1988 c - CARDI/CARIRI/UWI/WASA, 1979

d - Seaforth and Jones, 1978 e - Government of T&T, 1976 I - Delcan, 1994

APPENDIX Ι . - C: physicochemical ranges obtained in the caroni river basin

Riverine Stations

Temperature oC

Dissolved Oxygen

mg/L

Salinity %o

Conductivity µmhos/cm

pH Annual Mean

Discharge m3/s

San Juan 26.0-26.5a 1.25-2.1

0.2-7.9I

0

-

50-440

-

7.0-9.1

7.6-8.6

0.7-0.9f

-

St. Joseph 25.3-26.5a

-

0.9-7.3

5.0-7.5I

0

-

434-590

-

6.7-7.9

7.5-8.6

0.4f

-

Guayapo 24.3-28.2I 1.7-6.5 - 300-470 7.7-8.2 -

Tacarigua 22.6-28.2I 4.0-7.5 - - 7.5-8.2 0.4-0.7f

Arouca 25.2-29.3I 0.2-8.0 - 211-360 7.4-8.0 -

Oropuna 26.4-28.5I 2.0-7.1 - 189-320 6.7-9.8 -

Mausica -

-

-

27.7-28.6I

1.1-6.8b

2.6-5.2c

2.0-5.0d

5.2-7.3

-

-

-

-

-

207-409

-

174

5.9-7.6

7.0-7.7

6.3-7.1

7.6-7.9

-

-

-

-

Carapo/ Manacal

-

-

-

-

29.0-33.6I

2.0-7.3b

7.8-7.9e

0.6-3.1c

0.2-5.7d

4.7

-

-

-

-

-

-

103-254

112-442

-

-

7.2-7.5

6.4-7.2

6.8-7.7

6.5-6.8

-

-

-

-

-

-

Tumpuna -

-

4.7-6.2e

7.1-7.5b

-

-

222-320

-

7.4

7.3-7.6

-

-

Arima -

-

-

27.2I

7.8-7.9e

4.7-6.6c

6.9-7.6d

-

-

-

-

-

230-240

157-225

-

-

7.6-8.2

7.4-7.7

7.5-7.6

-

-

-

-

-

Guanapo -

-

7.8-7.9e

6.3-7.4b

-

-

193-196

-

7.6-7.7

7.3-7.5

1.2-1.6f

-

El Mamo -

-

7.8-7.9e

3.7-7.1b

-

-

120-169

-

6.8-7.1

7.2-7.4

0.3-0.5f

-

Aripo -

-

7.8-7.9e

6.3-7.0b

-

-

143-270

-

7.2-7.8

7.3-7.4

-

-

Cumuto - 7.8-7.9e - 124 7.0 -

Caroni -

-

-

26.0-29.3a

-

-

4.6-7.6b

0.0-7.9e

5.1-5.9c

0.8-6.7

4.4-7.0d

2.4-5.2I

-

-

-

-

0-9.0

-

-

122-269

146-221

297-9000

-

-

7.0-7.4

6.8-7.8

7.5

5.8-7.1

6.7-7.4

7.3-7.6

8.7-15.3f

-

-

-

-

-

a - Siung-Chang, et al., 1987 b - Wessex Water, 1988 c - CARDI/CARIRI/UWI/WASA, 1979

d - Seaforth and Jones, 1978 e - Government of T&T, 1976 f - Water Resources Agency, 1989

I - Delcan, 1994

APPENDIX Ι - D: FUNCTIONAL & NON FUNCTIONAL SEWAGE TREATMENT PLANTS IN TRINIDAD AND TOBAGO.

County Ward Functional Non-Functional Unclassified

1. St. George a

b

c

d

e

f

Diego Martin

St. Anns

Blanchisseuse

Tacarigua

Arima

San Rafael

6

8

--

10

4

--

--

2

--

10

2

--

1

3

--

13

15

--

Sub-Total 28 14 32

2. St. Andrew/

St. David

a

b

c

d

e

f

Toco

Valencia

Matura

Manzanilla

Tamana

Turure

1

--

1

1

--

1

--

--

--

3

--

--

--

--

--

2

--

1

Sub-Total 4 3 3

3. Caroni a

b

c

d

Cunupia

Chaguanas

Couva

Montserrat

1

2

3

1

--

6

4

1

3

15

2

--

Sub-Total 6 11 20

4. Nariva/Mayaro a

b

c

d

Charuma

Cocal

Trincity

Guayaguayare

--

--

--

--

--

--

--

--

--

1

--

3

Sub-Total 0 0 4

5. Victoria a

b

c

Pointe-a-Pierre

Naparima

Savanna Grande

--

5

1

--

1

--

1

5

--

d

e

Ortoire

Moruga

--

--

--

--

--

1

Sub-Total 6 1 7

6. St. Patrick a

b

c

d

Cedros

La Brea

Siparia

Erin

--

--

3

--

--

--

--

--

--

4

--

--

Sub-Total 3 -- 4

TOTAL Trinidad 47 29 70

Tobago

Parish Functional Non-Functional

St. Patrick 2 7

St. Andrew - 5

St. David - -

St. George - -

St. Mary 1 -

St. Paul - 1

St. John - -

Total in Tobago 3 13

Note: No Data available

Sources: Tota, A. Water and Sewerage Authority, St. Joseph, Trinidad. Per. Comm. 1991.

Ministry of Health, Barataria, Trinidad. Per. Comm. 1991.

WHO/PAHO, CEHI, St. Lucia. Per. Comm. 1991.

APPENDIX Ι .Ι .

AIR POLLUTION

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