gvi mexico punta gruesa september-december 2011 and 2008-2011 summary report

7/31/2019 GVI Mexico Punta Gruesa September-December 2011 and 2008-2011 Summary Report

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Global Vision International2011 Report Series No. 004

GVI Mexico

Punta Gruesa Marine Expedition

Mahahual

Quarterly Report 114

September - December 2011


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Global Vision International2011 Report Series No. 004

GVI Mexico, Punta Gruesa Expedition Report 114

Submitted in whole to

GVIAmigo de Sian KaanComisin Nacional de reas Naturales Protegidas (CONANP)

Produced by

Esther Hantman Field staffMaura Schonwald-Field staff

Lluvia Soto Country DirectorAnd

Bryan Becker Base Manager Debbie Thompson VolunteerBen Booth Field Staff Jamie Krawciw VolunteerLaura Mchugh Field Staff Meredith Cavanagh Volunteer

Ariadna Armas Field Staff Matt Peyton VolunteerTila Williams Field Staff Kriss Saunders Volunteer

Patrick Brydon Scholar Thomas Mitchel VolunteerRachael Ross Scholar Catherine Rossilin VolunteerKelly Rensing Volunteer Peter Hollekim Volunteer

Breanna Thompson Volunteer Peter Osbourne VolunteerPeter Waite Burton Volunteer Heather Exley Volunteer

Dave Shepard Volunteer Evan Raymond Volunteer

Mischa Williamson Volunteer Elizabeth Dawber VolunteerMicheal Grall Volunteer Rebecca Fox VolunteerJana Dlouha Volunteer Ixchel Garcia NSPCaroline Ble Volunteer Rosie Sheba Volunteer

Neils Prinssen Volunteer Simon Brownlie Volunteer

Edited by

Esther Hantman

Lluvia Soto

Daniel Ponce-Taylor

GVI Mexico, Punta Gruesa

Email:[email protected] page:http://www.gvi.co.uk andhttp://www.gviusa.com
mailto:[email protected]:[email protected]:[email protected]://www.gvi.co.uk/http://www.gvi.co.uk/http://www.gvi.co.uk/http://www.gviusa.com/http://www.gviusa.com/http://www.gviusa.com/http://www.gviusa.com/http://www.gvi.co.uk/mailto:[email protected]


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GVI 2011 ii

Executive Summary

The 16th, and last, ten-week phase of the Punta Gruesa, Mexico, GVI expedition has now

been completed. Due to a revision of its national objectives and reassessment of theavailable resources, it has been decided that the activities on this location will not be

continued after December 2011. This report will serve as a summary of the activities

completed at Punta Gruesa. Further detailed analysis of the data collected during this time

will be carried out and submitted to peer-reviewed journals for its publication. During the

duration of the program, GVI maintained working relationships with local communities

through both English classes and local community events. The programme continued to

work towards the gathering of important environmental scientific data whilst working with

local, national and international partners. The following projects were run during the wholeduration of the programme, as well as on the last quarter (September- December 2011):

Coral reef monitoring of strategic sites along the coast.

Training of volunteers in the MBRS methodology including fish, hard coral, and

algae identification.

Continuing the MBRS Synoptic Monitoring Programme (SMP) for the selected sites

within the Mahahual region to provide regional decision makers with up to date

information on the ecological condition of the reef. Providing English lessons and environmental education opportunities for the local

community.

Further developing the current Marine Education programme for the children of

Mahahual that works alongside the standard curriculum.

Adding new reported coral and fish species to the on growing species list compiled

during the duration of the program. This list will serve as a comprehensive guide

for the region.

Weekly beach cleans within the area, monitoring waste composition and trends. Daily bird monitoring and incidental sightings programme.


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iii

Table of Contents

Executive Summary ............................................................................................................. iiList of Figures.......................................................................................................................4List of Tables ........................................................................................................................41. Introduction .................................................................................................................52. Synoptic Monitoring Programme ................................................................................7

2.1 Introduction ...........................................................................................................72.2 Aims ......................................................................................................................92.3 Methodology..........................................................................................................92.4 Results ................................................................................................................112.5 Discussion ...........................................................................................................24

3. Community programme .................................................................................................293.1 Introduction .........................................................................................................293.2 Aims ....................................................................................................................293.3 Activities and Achievements ...............................................................................293.4 Review ................................................................................................................30

4. Incidental Sightings........................................................................................................324.1 Introduction .........................................................................................................324.2 Aims ....................................................................................................................324.3 Methodology........................................................................................................324.4 Results ................................................................................................................334.5 Discussion ...........................................................................................................35

5. Marine Litter Monitoring Programme. ............................................................................375.1 Introduction .........................................................................................................375.2 Aims ....................................................................................................................375.3 Methodology........................................................................................................375.4 Results ................................................................................................................385.5 Discussion ...........................................................................................................39

6. Bird Monitoring Programme...........................................................................................41

6.1 Introduction .........................................................................................................416.2 Aims ....................................................................................................................416.3 Methodology........................................................................................................426.4 Results ................................................................................................................426.5 Discussion ...........................................................................................................45

7. Seagrass Monitoring Programme..................................................................................477.1 Introduction .........................................................................................................477.2 Aims ....................................................................................................................477.3 Methodology........................................................................................................477.4 Results ................................................................................................................487.5 Discussion ...........................................................................................................49

8. Summary ........................................................................................................................50

9. References .....................................................................................................................5210. Appendices ..................................................................................................................54

Appendix I SMP Methodology Outlines .................................................................54Appendix II - Adult Fish Indicator Species List .........................................................58Appendix III - Juvenile Fish Indicator Species List...................................................59Appendix IV - Coral Species List ..............................................................................60Appendix V - Fish Species List .................................................................................61Appendix VI a - Bird Species List .............................................................................66


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4

Appendix VI b - Bird Species List .............................................................................67

List of Figures

Figure 2-3-1 The Dive Sites of Punta Gruesa

Figure 2-4-1 Percentage Cover of Hermatypic Coral and Macroalgae by phase.

Figure 2-4-2 Percentage Cover of Hermatypic Coral on each site by phase.

Figure 2-4-3 Benthic composition breakdown.

Figure 2-4-4 Most common coral seen per phase

Figure 2-4-5 Disease occurrence by phase.

Figure 2-4-6 Predation occurrence by phase.

Figure 2-4-7 Percentage of colonies bleached from 2008 to 2011.

Figure 2-4-8. Bleaching Occurrence 081-114

Figure 2-4-9 Adult fish recorded per transect across phases

Figure 2-4-10 Total adult fish biomass per phase

Figure 2-4-11 Average Percentage Abundance of Adult Fish by Family: Phases 081-104

Figure 2-4-12 Changes in adult fish family percentage abundance

Figure 2-4-13 Percentage abundance per family from January 2008 to December 2011.

Figure 2-4-14 Percentage abundance of juvenile fish families by phase

Figure 4-4-1 Total number of incidental sightings recorded by phase

Figure 4-4-2 Number of lionfish sightings per phase from June 2009 until December 2011.

Figure 5-4-1 Average Weight of Litter Collected per Week by Phase (Kg)

Figure 5-4-2 Breakdown of rubbish collected since 092 to 114 in kg.

Figure 6-4-1 Most common bird species or families recorded during phase 114

Figure 6-4-2 Species observed from 092 to 114

List of Tables

Table 2-3-1 Name, Site ID, Depth and GPS points of the monitoring sites

Table 2-4-1 Coral colonies monitored by CC at Punta Gruesa

Table 2-4-2 Number of transects and adult fish recorded per phase.

Table 2-4-3 Number of transects/juvenile fish recorded per phase

Table 4-4-1 Breakdown of species recorded in 114

Table 6-4-1 Most common species recorded since 092 to 114.

Table 7-3-1 GPS positions for sea grass transects


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1. Introduction

The Yucatan Peninsula is fringed by the Mesoamerican Barrier Reef System (MBRS), the

second largest barrier reef system in the world, extending over four countries. Starting

from Isla Contoy at the North of the Yucatan Peninsula it stretches down the Eastern coast

of Mexico down to Honduras via Belize and Guatemala.

The project at Punta Gruesa, in collaboration with a sister base in Pez Maya located inside

the Sian Kaan Biosphere Reserve, assisted our project partners, Amigos de Sian Kaan

(ASK) and Comisin Nacional de reas Naturales Protegidas (CONANP) in obtaining

baseline data along the coast of Quintana Roo through marine surveys. This data allows

ASK to focus on the areas needing immediate environmental regulation depending on

susceptibility and therefore, implement management protection plans as and whenrequired.

Such a project is especially significant in current times of rapid development along the

small fishing village coast of the Mahahual area due to the tourism industry generated by

the cruise ship pier that was built near the town in 2002.

The project at Punta Gruesa will not continue running, therefore this is the last report

produced. During the time the programme was running the methodologies continued to beimproved and focused as experience was gained and improvement to data quality was

continuous. This report collates and summarizes all the data collected from January 2008

until December 2011. The following research/monitoring programmes were carried out

during the last four years:

The MBRS Synoptic Monitoring Programme

Community Work Programme

Incidental Sightings

Marine Littering Monitoring Programme

Bird Monitoring Programme

Seagrass Monitoring Programme


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Note: The monitoring periods throughout the year are defined, within this report, as

phases. Each year is divided into 4 phases or quarters. Each quarter receives a numerical

code, comprised of the last two digits of the year (i.e. 09 for 2009) and the number of the

quarter during that specific year (i.e. 2 for the 2 nd quarter of the 2009). For example 093

represents the 3rd quarter or phase of 2009.


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2. Synoptic Monitoring Programme

2.1 Introduction

The Synoptic Monitoring Programme looks to evaluate the overall health of the reef bylooking at three main areas: Benthic cover, fish populations and physical parameters.

Benthic Cover

Caribbean reefs were once dominated by hard coral, with huge Acropora palmatastands

on the reef crests and Acropora cervicornisand Montastraea annularisdominating the fore

reef. Today, many reefs in the Caribbean have been overrun by macro algae during a

phase shift which is thought to have been brought about by numerous factors including a

decrease in herbivory from fishing and other pressures, eutrophication from land-basedactivities and disease (McClanahan & Muthiga, 1998).

Benthic transects record the abundance of all benthic species as well as looking at coral

health. The presence of corals on the reef is in itself an indicator of health, not only

because of the reefs current state, but also for its importance to fish populations (Spalding

& Jarvis, 2002). Coral health is not only impacted by increased nutrients and algal growth,

but by other factors, both naturally occurring and anthropogenically introduced. A report

produced by the United Nations Environment Programme World Conservation MonitoringCentre (UNEP-WCMC) in 2004 stated that nearly 66% of Caribbean reefs are at risk from

anthropogenic activities, with over 40% of reefs at high to very high risk (UNEP-WCMC,

2006).

Through monitoring the abundances of hard corals, algae and various other key benthic

species, as well as numbers ofDiademaurchin encountered, we aim to determine not only

the current health of the local reefs but also to track any shifts in phase state over time.

Fish Populations

Fish surveys are focused on specific species that play an important role in the ecology of

the reef as herbivores, carnivores, commercially important fish or those likely to be

affected by human activities (AGRRA, 2000).


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For more in depth rationale of the importance of each of the key fish families please see

previous GVI Mahahual/Punta Gruesa reports, they can be found and downloaded in our

blog: www.gvimexico.blospot.com

All reef fish play an important role in maintaining the health and balance of a reefcommunity. Fishing typically removes larger predatory fish from the reef, which not only

alters the size structure of the reef fish communities, but with the reduction in predation

pressure, the abundance of fish further down the food chain is now determined through

competition for resources (AGRRA, 2000).

Although each fish is important, the removal of herbivores can have a considerable impact

on the health of the reef, particularly in an algal dominated state, which without their

presence has little chance of returning to coral dominance. Through the monitoring ofthese fish and by estimating their size, the current condition of the reef at each site can be

assessed, any trends or changes can be tracked and improvements or deteriorations

determined.

The monitoring of juvenile fish concentrates on a few specific species. The presence and

number of larvae at different sites can be used as an indication of potential future

population size and diversity. Due to the extensive distribution of larvae, however,

numbers cannot be used to determine the spawning potential of a specific reef. Theremoval of fish from a population as a result of fishing, however, may influence spawning

potential and affect larval recruitment on far away reefs. The removal of juvenile predators

through fishing may also alter the number of recruits surviving to spawn themselves

(AGRRA, 2000).

Together with the information collected about adult fish a balanced picture of the reef fish

communities at different sites can be obtained.

Physical Parameters

For the optimum health and growth of coral communities certain factors need to remain

relatively stable. Measurements of turbidity, water temperature, salinity, cloud cover, and

sea state are taken during survey dives. Temperature increases or decreases can

negatively influence coral health and survival. As different species have different optimum


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temperature ranges, changes can also influence species richness. Corals also require

clear waters to allow for optimal photosynthesis. The turbidity of the water can be

influenced by weather, storms or high winds stirring up the sediment, or anthropogenic

activities such as deforestation and coastal construction. Increased turbidity reduces light

levels and can result in stress to the coral. Any increase in coral stress levels can result inthem becoming susceptible to disease or result in a bleaching event.

2.2 Aims

The projects at Punta Gruesa and Pez Maya aim to identify coral and fish species with a

long term, continuous dataset allowing changes in the ecosystem to be identified. The

projects also aim to ascertain areas of high species diversity and abundance. The data is

then supplied to the project partners who can use the data to support management plansfor the area.

2.3 Methodology

The methods employed for the underwater visual census work are those outlined in the

MBRS manual (Almada-Villela et al., 2003), but to summarize, GVI use three separate

methods for buddy pairs:

Buddy method 1: Surveys of corals, algae and other sessile organisms

Buddy method 2: Belt transect counts for coral reef fish

Buddy Method 3: Coral Rover and Fish Rover diver

The separate buddy pair systems are outlined in detail in Appendix I.

The 9 sites that are monitored as part of the MBRS programme at GVI Punta Gruesa,

detailed below, were chosen through discussions with ASK, the Programa de Manejo

Integrado de Recursos Costeros (MIRC, a subsidiary of UQROO) and discussions with

local fishermen.

These sites make up a coastal range of 6.5km in the immediate vicinity of Punta Gruesa

(See Figure 2-3-1 below) and were monitored every 3 months to give a long term

evaluation of the reef health.


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Figure 2-3-1 The Dive Sites of Punta Gruesa


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Table 2-3-1 Name, Site ID, Depth and GPS points of the monitoring sites.

GPS points are listed here in the WGS84 datum.

The position format is hddd mm ss.s

The eight sites at 10m are situated on the reef crest with one deeper site Los Gorditos,

which offers a wide sample area with spur and groove formations.

2.4 Results

From January 2008 to December 2011, a total of 550 coral transects and 900 fish

transects were done.

Benthic Data

One of the main focuses of the coral monitoring was the coral coverage against the algae

cover. The reefs around the area showed an average coral cover of 10.46% and 66.34%

of macroalgae. The coral cover has maintained relatively stable since January 2008 when

the survey began, it ranged from 7.6% (phase 083) up to 13.1% (phase 112). The

macroalgae cover ranged from 60.8% (phase 104) to 72.9% (phase 103). In a year by

year comparison, it had been observed that the lowest average cover of macroalgae was

during the fourth quarter (September-December) of each year with the exception of the

this last quarter (October-December 2011).

Site Name Site ID Depth Latitude Longitude

Los Bollos LB10 10m 190221.8 0873354.8

Las Joyas LJ10 10m 190153.0 0873407.6Los Milagros LM10 10m 190136.7 0873415.9Costa Norte CN10 10m 190131.0 0873416.5Las Delicias LD10 10m 190124.7 0873420.2

Las Palapas LP10 10m 190155.8 0873405.1Flor de Can FDC10 10m 190204.4 0873403.8

Sol Naciente SN10 10m 190036.0 0873433.0Los Gorditos LG25 25m 185937.6 0873451.9


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Figure 2-4-1 Percentage Cover of Hermatypic Coral and Macroalgae by phase.

The site with the highest coral cover percentage was LJ with an average of 14.84%. This

site registered the maximum coverage since the survey began with 21.17% on phase 094

(Sept Dec 2009). LJ was also the site with the lowest macro algae cover registered. The

site with the lowest coral cover was LD with an average of 7.21%. Across the phases LD

and FDC were the sites with the lowest numbers recorded. LD was the site that had the

highest values on macro algae coverage. Due to weather conditions, not all the sites were

monitored every phase, therefore there is some information missing for some of the

phases, as can be observed in Figure 2-4-2.


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Figure 2-4-2 Percentage Cover of Hermatypic Coral on each site by phase.

The four main components of the benthos were macroalgae (66.34%), followed by

corallinales (coralline algae) with 14.72% coverage, hermatypic coral with 10.46% and

sponges with 3.62% coverage.

Figure 2-4-3 Benthic composition breakdown.

The most common coral registered was Agaricia agaricites with a total of 1972 colonies

which represents 28.23% of the corals recorded. The second most common was

Siderastrea sidereawith 1737 colonies representing 26.28%. The most uncommon coral


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was Isophyllia sinuosa with only one colony recorded since the survey began in Pta

Gruesa.

Figure 2-4-4 Most common coral seen per phase

During the time the project was running, a total of 9714 colonies were monitored as part of

the coral communities survey, in a total of 550 transects.

Table 2-4-1 Coral colonies monitored by CC at Punta Gruesa

Phase Transects Colonies

081 21 410082 32 558

083 35 523084 34 517

091 39 542

092 30 554

093 45 767

094 45 831

101 45 684

102 35 632

103 44 771

104 35 679

111 20 396

112 45 971

113 20 479114 25 400

Of the total of 9714 monitored colonies, 506 colonies presented some kind of disease

accounting for the 5.20%. The most common disease was Dark spot followed by the Red

Band disease. There was a steady increase in disease occurrence until the final of 2010.

Since the start of 2011 the occurrence of coral disease has seen a decrease, but not


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reaching the low levels of 2008. Incidence of disease was recorded over a wide variety of

coral genus. Agaricia, Dichocoenia, Diploria, Helioceris, Meandrina, Montastraea,

Siderastrea and Stephanocoenia were all affected, and in some genus, Montastraea in

particular, multiple species showed multiple diseases to be present.

Figure 2-4-5 Disease occurrence by phase(BBD-Black band disease; DS-Dark spot; YBD-Yellow blotchdisease; RBD-Red band disease; WP-White plage).

Predation, of some sort, was present in 576 colonies accounting for the 5.9% of the

colonies studied. The most common type of predation was sponge predation which

affected 525 colonies, followed by gorgonian predation, which affected 79. The type of

predation that has the lowest number of records was fire worm predation.

Figure 2-4-6 Predation occurrence by phase.


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Since the survey began in 2008, 2953 coral colonies presented some kind of bleaching,

accounting for a 30.39% of the total recorded colonies. A yearly pattern was observed

whereby the number of beached colonies increased towards the last quarter of every year

with the exception of 2010 when the major bleaching event was during the third quarter of

the year. Phase 094 (October-December 2009) had the highest number of bleachedcolonies since the survey began; while phase 112 (March-June 2011) had the lowest.

Figure 2-4-7 Percentage of colonies bleached from 2008 to 2011.

Siderastrea sidereais the most common coral where bleaching was observed, often found

to be pale bleached and has therefore been separated from the other corals so as not to

bias the results and obscure any bleaching patterns in other corals. There was a dramatic

decrease in the bleaching occurrence in Siderastrea sidereacolonies during Phase 104

that continued to decrease towards the end of 2011 (phase 114), which has the lowest

records of bleaching for this species.


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There was also a decrease in bleaching occurrence in other coral species although to a

lesser extent.

Figure 2-4-8. Bleaching Occurrence 081-114


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Fish Populations

From January 2008 to December 2011 a total of 13,148 adult fish were registered on a

total of 900 transects. The phase with the highest number of individuals recorded was 112

and the phase with the lowest record was 084 despite the fact that it was not the phasewith the lowest number of transects undertaken.

Table 2-4-2 Number of transects and adult fish recorded per phase .

Phase Transects per

phase

Total target adult

fish in phase

Av. fish per

transect

No. of species

081 30 391 13.03 31

082 54 649 12.02 33

083 49 280 5.71 27

084 40 321 8.03 28

091 39 328 8.41 29092 48 843 17.56 36

093 72 809 11.24 38

094 72 1282 17.81 38

101 72 1264 17.56 40

102 56 1050 18.75 31

103 72 792 11.00 33

104 64 879 13.73 30

111 40 360 9.0 28

112 72 1453 20.18 35

113 64 1436 22.44 33

114 56 1011 18.05 34

Figure 2-4-9 Adult fish recorded per transect across phases


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Adult fish biomass is estimated using a weighting system for each size category and

species (Froese & Pauly, 2006, figures obtained from table constructed by A. Cameron).

Total biomass of all target adult fish species in 104 was calculated to be 4.59 kg 100 m -2

(Figure 2-4-14). This brings the average biomass for our study area to 3.87 kg 100 m-2

from January 2008 to December 2011.

Figure 2-4-10 Total adult fish biomass per phase (the black line is the average biomass, 3.87 kg 100m2)

Following previous trends, the Haemulidae was the most commonly recorded family over

all phases, with 50.86% of the total number observed. The second most abundant family

was the Acanthuridae with 20.99%. Sphyraenidae (Great Barracuda) are rarely recordedin transects in any phase, although they have been observed outside of transects (see

Incidental Sightings section).

Figure 2-4-11 Average Percentage Abundance of Adult Fish by Family: Phases 081-104


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In previous phases it was noted that the two dominant families, Haemulidae and

Acanthuridae, appeared to be showing a link in abundance: where one increased the other

decreased and vice versa. This pattern continued to be observed this last monitoring

quarter. The percentage abundances of Pomacanthidae and Pomacentridae increasedand decreased in sync with each other between Phases 082 and 102, then again from 111

to 114 (Fig 2-4-12).

Balistidae and Monacanthidae are grouped together. The percentage abundance of this

collective group declined dramatically between 081-091 but since then numbers increased

slightly and remained relatively stable until 2011 when they showed a big increase on the

first quarter to then have a great decrease for the following months .


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Figure 2-4-12 Changes in adult fish family percentage abundance

A total of 12,611 juveniles were recorded in the 900 transects completed. Across the four

years of data collection, juvenile numbers seem to be higher in the second and third

phases of the year and lowest during the firs t phase of the year.


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Table 2-4-3 Number of transects/juvenile fish recorded per phase

Phase Transects perphase

Total juvenile fish inphase

Av. Juvenile fishper transect

081 30 302 10.07

082 54 815 15.09

083 49 606 12.37

084 40 308 7.70

091 39 224 5.74

092 48 862 17.96

093 72 2150 29.86

094 72 570 7.92

101 72 437 6.07

102 56 1211 21.63

103 72 1145 15.90

104 64 495 7.73

111 40 174 4.35112 72 901 12.51

113 64 1932 30.19

114 56 479 8.43

Stegastes partitus is, on average, the most abundant juvenile species recorded and

numbers are lowest during the fourth phase each year, however, the next three most

abundant species all tend to be lowest in numbers during the first phase each year. The

four lowest abundances forHalichoeres garnotiand forSparisoma aurofrenatumwere all

from the first phases of the year, and three of the four lowest abundances of Stegastes

partitus were also in the first phase of the year. This could explain the annual cyclical

pattern observed in juvenile fish abundance.

A total of six juvenile fish families were recorded on transects from January 2008 to

December 2011. The most abundant family was Labridae, which made up 50.91% of

recorded juveniles.


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Figure 2-4-13 Percentage abundance per family from January 2008 to December 2011.

There appears to be some link in percentage abundance between Labridae and

Pomacentridae juveniles, with one decreasing as the other increases. Scaridae

abundance is quite variable; their numbers seem to peak during the fourth phase of each

year. Acanthuridae, Chaetodontidae and Grammatidae juvenile numbers on the reef

remain low across all phases.

Figure 2-4-14 Percentage abundance of juvenile fish families by phase


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2.5 Discussion

Benthic data

Coral cover on reefs across the Caribbean has decreased dramatically over the past three

decades from about 50% to 10% cover (Gardner et al., 2003). Although the coral cover at

Punta Gruesa is lower than it has been in the past, it is in line with other values reported

for this region. The average percentage coral cover over all monitored years was 10.46%.


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This percentage of coral cover is slightly below the regional average of 11% but it is above

the Mexico Yucatan average of 7.5% (Wilkinson, 2008).

The macroalgae cover is dramatically higher (66.34%) than the regional average of 18%

and the Mexico Yucatan average of 14.9% (Wilkinson, 2008). AGRRA (2005) states that

the average macroalgae cover for the Mesoamerican Reef is 25% and the Caribbean

average is 34%. There is a certain degree of variation between these figures but,

regardless of which is correct, the values calculated at Punta Gruesa are consistently

significantly higher. Rogers & Miller (2006) found that when new substrate was made

available in one Caribbean site following a severe hurricane, algae colonized the newly

available substrate and, once established, slowed or prevented new coral colonization.

Hurricane Dean was a powerful Category 5 Hurricane that made land fall in Mahahual in

August 2007 (Franklin, 2008), so it is possible that this may be the reason for the highmacroalgae cover in this region.

The three lowest average values of macroalgae cover at Punta Gruesa all occur during the

fourth phase of each year with the exception of the last monitored phase (October-

December 2011). Dawes et al. (1974) carried out studies on three species of macroalgae

(Eucheuma sp.) in Florida and found that they exhibited peak rates of growth in the spring

and lower rates of growth in the summer/fall. These lower summer growth rates were due

to high temperatures, increased light intensities and a decrease in available nutrients. The

monitoring during the fourth phase of each year occurred after these low rates of growth

and before peak growth rates in spring and so could explain the observed pattern.

Over all the phases, 30.93% of the colonies monitored were recorded as suffering from

some sort of bleaching. Bleaching in 2010 peaked in the Phase 103, slightly earlier than in

2008, 2009 and 2011 when it peaked in the fourth phase. Studies have recorded that

temperature increases of 1C above average for a sustained period (i.e. a month) can

cause mass bleaching (Hoegh-Guldberg, 1999). This can also be amplified by calm seas,

allowing more photosynthetically active radiation to penetrate the surface waters

(Sheppard et al., 2009). This would roughly explain the annual pattern that has been

observed here since 2008. NOAA (2010) observed that, since March 2010, monthly sea-

surface temperature averaged over the whole of the main cyclone development region

(which includes the Caribbean Sea and tropical Atlantic Ocean) have been at record


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Gruesa is calculated using target fish species only, whereas the figures given above could

have included additional species as it was not specified in the bibliography.

In the report for Phase 101 it was mentioned that surveyor error in sizing estimates may

have biased the data for 094. Although training is rigorous and volunteers must showconsistently high accuracy in identification and sizing estimates prior to beginning

monitoring, there will always be some degree of human error in data collection, particularly

in size estimates done by eye. Studies suggest that visual sizing by non-specialist divers

will achieve 80% accuracy by the third trial (Darwall & Dulvy, 1996), and that this is not

significantly different from observations by experienced observers. Without recourse to

expensive recording equipment, error in this area is as minimised as practically possible.

In previous phases it was noted that the two dominant families, Haemulidae andAcanthuridae, appeared to be showing an inverse link in abundance: where one increased

the other decreased and vice versa. This pattern continued every phase. As these families

occupy differing niches within the coral reef ecosystem, it is unlikely that populations

should have a direct effect on one another. Acanthuridae feed throughout the day on a

wide variety of plants on the reef (DeLoach, 1999), while most Haemulidae are carnivores

feeding nocturnally on crustaceans in the sand flats and seagrass beds (Humann &

DeLoach, 2008). This habitat preference may explain why both species are less frequently

recorded on the deeper site LG than at the shallower reef crest sites with easier access tofeeding grounds (see previous reports from Punta Gruesa available on:

www.gvimexico.blogspot.com).

The percentage abundances of Pomacanthidae and Pomacentridae (represented only by

the yellowtail damselfish, Microspathadon chrysurus) increased and decreased in sync

with each other between Phases 082 and 102 but this pattern has not continued since

then. These two families also occupy different niches within the coral reef ecosystem so;

once again, it is unlikely that their populations should have a direct effect on each other.Pomacanthidae are sponge-eating species. The tissue from a wide variety of sponges

making up 95% of the food consumed by species in the genus Holacanthus, and 70% in

the genus Pomacanthus. Microspathadon chrysurus, however, farm and defend

permanent territories of filamentous algae that surround their centrally-located hiding holes

(DeLoach, 1999).


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Throughout the four years of data collection, juvenile numbers have exhibited a cyclic

pattern, with abundance being greatest in the second and third phases of the year and

lowest during the first phase of the year. This pattern is mostly driven by abundance of

Stegastes partitus (Bicolor damselfish), Thalassoma bifasciatum (Bluehead wrasse),Sparisoma aurofrenatum (Redband parrotfish) and Halichoeres garnoti (Yellowhead

wrasse) all of which are recorded in great numbers each year at Punta Gruesa and all of

which are highest in numbers during the second and third phases. These results can be

explained by spawning cycles. Although many species settle randomly throughout the

year, recruitment reaches its peak in the summer(DeLoach, 1999).

The most abundant juvenile family recorded was Labridae, which made up 50.91% of

juveniles over all phases. This is partly due to the fact that there are six different species

within this family that are recorded, but is also due to the very high numbers of

Thalassoma bifasciatumand Halichoeres garnoti.

There appears to be some link in percentage abundance between Labridae and

Pomacentridae juveniles, with one decreasing as the other increases. This may be the

result of spawning cycles. Scaridae abundance is quite variable; their numbers seem to

peak during the fourth phase of each year.GVI Mexico team will continue to analyze the

data to try to identify the patterns as well as their correlation.


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3. Community programme

3.1 Introduction

GVI is committed to working with the local communities, aiming and assisting in thesustainable development of Mahahual. For that, we centred our activities in two main

aspects: English and Environmental Education.

GVI hoped to provide locals in Mahahual with the tools to develop the area beneficially for

local inhabitants, local professions and needs, whilst protecting it for the future.

Consequently, during both the child and adult education programs, wherever possible an

environmental theme was included within the structure of the lessons.

3.2 Aims

The aims of the community programme in Punta Gruesa were:

1. To raise awareness about the importance of the ecosystems that surround their

area, providing them with information about it and organizing activities to reinforce

the knowledge given.

2. To provide locals with English lessons that will help them to develop a skill that is

necessary for them in order to be able to communicate with the growing tourist

visitors that come to the area.

3. To participate in the different activities that are organized by the locals and provide

help if it is needed.

3.3 Activities and Achievements

A wide range of activities were done during the time GVI Mexico worked in Mahahual area

since 2004, having as the main activities the English lessons and the Environmental

Education. The expedition moved to a different location on 2008, Punta Gruesa, but

continued to work with the local community of Mahahual.

Once a week the volunteers prepared lessons to be delivered to different groups of

students from primary school children, teenagers and adults. Games, interactive activities

and songs are some of the tools they used to reinforce the knowledge. After the lesson

volunteers and staff had feedback sessions to debrief and comment on the lessons

developments and achievement of its initial objectives.


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The lessons were delivered at different times, morning and evenings, and they were

rescheduled depending on the number of attendees. On the last period of the programme,

the evening lessons were the most successful due to the working times of the majority of

the adult students, who are mainly taxi drivers, builders, waiters, masseuses and salespeople, and for the school students who voluntarily attend because they wanted (or their

parents wanted them) to spend extra time working on their English, without interrupting the

normal flow of the school day, or sharing those classes with uninterested students.

Attendances varied through the years having groups of 1 up to 75 students. There were

different locations, from schools, hotels and even restaurants in Mahahual, Las Casitas

and El Uvero.

The Environmental Education was a key component of the community work done duringthe time GVI Mexico worked in the area. There was a variety of activities done, from

lessons and games to the organization of different festivities like Project Awares Dive into

Earth Day, where the volunteers and staff took teenagers snorkelling and diving to know

more about the reef ecosystems. There was a regular participation in every beach and reef

clean organized by the community as well as mangrove clean and lionfish fishing event.

Other activities outside Mahahual where GVI Punta Gruesa also participated were the

Turtle camp in Xcacel, where the volunteers spent nights patrolling the beaches looking forturtles nestings, and the Turtle Festival organized by different NGOs to celebrate the

ending of the nesting season.

3.4 Review

The community programme was very successful during the 4 years that GVI was based at

Punta Gruesa. Volunteers and staff delivered English lesson to more than 250 students of

different ages and levels of knowledge. The lessons were of great importance as they

helped the local community to develop the necessary skills to work in the tourist industry,

which is one of the main activities in the area.

The Environmental Education programmes gave the opportunity to the locals to know

more about the different habitats that surround Mahahual and the importance of each of


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them. The lessons were given to both children and adults and had a variety of games,

songs and activities according to the audience.

GVI Punta Gruesa continued to participate in other activities organized by the people in

Mahahual like the Project Awares Dive into Earth Day, Lionfish hunting competitions,Jatsa Ha Festival, Mahahuals carnival, Beach and Reef cleans, etc, where volunteers,

staff and the local community had the opportunity to interact and learn from each other.

The community programme and the work done by the volunteers will be missed in town.


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4. Incidental Sightings

4.1 Introduction

GVI Punta Gruesa implemented an incidental sightings program since January 2008,

following on from the previous Mahahual bases data since 2004. This is due to the high

number of turtles and other mega fauna species seen on dives in the area. Species that

make up the incidental sightings list are:

Sharks and Rays

Eels

Turtles

Marine Mammals

Great Barracuda

Lionfish

These groups are identified to species level where possible and added to the data

collected by the Ocean Biogeographic Information Systems Spatial Ecological Analysis of

Mega vertebrate Populations (OBIS-SEAMAP) database. An interactive online archive for

marine mammal, seabird and turtle data, OBIS-SEAMAP aims to improve understanding

of the distribution and ecology of marine mega fauna by quantifying global patterns of

biodiversity, undertaking comparative studies, and monitoring the status of and impacts on

threatened species.

4.2 Aims

The aim of the project was to record all mega fauna sightings in the vicinity of Punta

Gruesa and to keep track of the population numbers and spread of lionfish.

4.3 MethodologyEach time an incidental sighting species was seen on a dive or snorkel it was identified,

and the date, time, location, depth it was seen at, and size were all recorded. The

volunteers were provided with a Mega fauna presentation during science training, which

aids in identification of shark, ray and turtle species. All the completed dives were logged

by GVI, showing the total effort for each phase in comparison with the species recorded.


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For the first time during phase 093, July - September 2009, GVI Punta Gruesa began

recording lionfish sightings. Over the past decade the Pacific Lionfish (Pterois volitansand

P. miles) has established itself along the Atlantic coast as a result of multiple releases

(intentional or otherwise) from private aquaria. This invasive species lacking in naturalpredators, has adapted well to the warm waters of the Caribbean, and is currently

spreading its geographical range along the Mesoamerican coastline.

4.4 Results

During this phase a total of 279 incidental sightings were recorded (not including lionfish or

great barracuda) across 266 trips out to the reef. This equates to a unit effort of 1.04

sightings per boat. These figures also include anything spotted during snorkel trips to the

lagoon but the total number of snorkel trips that were made is unknown.

Figure 4-4-1 Total number of incidental sightings recorded by phase

Three species of elasmobranchs were registered with the southern stingray as the most

common one. While the spotted moray eel was the most common species registered of

the three species registered on the moray eels group.


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Only two species of dolphins were recorded and three species of marine turtles.

Table 4-4-1 Breakdown of species recorded in 114

Elasmobranchs

Species

No.

IndividualsNurse sharks (Ginglymostoma cirratum) 1

Southern stingray (Dasyatis americana) 82

Spotted eagle ray (Aetobatus narinari) 14

Unidentified rays 13

Moray eels

Green moray (Gymnothorax funebris) 12

Spotted moray (Gymnothorax moringa) 18

Golden tail moray (Gymnothorax miliaris) 3

Unidentified eels 6

Marine turtles

Loggerhead (Caretta caretta) 9

Hawksbill (Eretmochelys imbricate) 15Green (Chelonia mydas) 3

Unidentified 10

Marine mammals

Atlantic spotted dolphin (Stenella frontalis) 17

Bottlenose dolphin (Tursiops truncatus) 12

Unidentified 65

Lionfish Pterios sp. 161

Great barracuda Sphyraena barracuda 186

Total 626

186 great barracuda were recorded, including six sightings at the site LC (Las Cavernas)

of groups of 11-23 individuals swimming together. They ranged in size from 0.5-1.5m in

length.

161 lionfish were recorded during phase 114. They ranged in size from 1-40cm but were

most common in the over 26cm category (44 individuals). 18 of these were killed and

another four wounded in an attempt to control lionfish numbers on the reef.

From June 2009 to December 2011, a total of 1380 lionfish were registered.


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Figure 4-4-2 Number of lionfish sightings per phase from June 2009 until December 2011.

4.5 Discussion

A total of 279 incidental sightings were recorded this last phase. Figure 4.1 shows that the

number of incidentals drops every other year in the fourth phase and reaches a peak in the

fourth phase of the following year.

The most common species recorded this last phase was the southern stingray (Dasyatis

Americana), which is consistent with data from previous phases.Southern stingrays have

been the most common elasmobranchs recorded every phase since monitoring began

here at the start of 2008, with the exception of phase 083 (July-September 2008). They

tend to spend a lot of time partially buried in the sand, just off the reef wall. They are often

very conspicuous from the dive sites, which may partially explain the high numbers

recorded. Also, when carrying out monitoring and training dives we repeatedly visit the

same sites so it is possible that we may count the same rays more than once.

There were 15 hawksbill turtles were sighted this phase which is the highest number since

phase 093 (June-September 2009). A total of 37 turtles were recorded in total which is the

highest number recorded since monitoring began here at the start of 2008.

There were 186 great barracuda sightings during this phase. This is the highest number

recorded at Punta Gruesa. 113 of the barracuda recorded were at the site LC (Las

Cavernas) accounting for a large number of the overall sightings. Barracuda were seen at

this site in schools with numbers ranging from 11 to 23 per quarter. Repeated visits to this


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site could also explain the high numbers. This behaviour is unusual as barracuda are

usually solitary. The numbers of barracuda were also high in 2009, 134 were sighted in

phase 092 (April-June 2009) with schools being recorded of up to 20, sightings dropped in

2010 with only 32 sightings during the whole year.

The number of dolphins (93) seen this phase is the highest number since phase 101

(January-April 2010). This number is significantly higher than the average recorded over

all other phases of 38 dolphins.

161 lionfish were recorded during this phase. This is lower than numbers recorded in the

last two phases. Previous data has shown a steady increase in the population of lionfish in

phase 092 (April-June 2009) 3 lionfish were recorded. The increase in Pterois volitansand

P. milessightings poses a potentially large problem for the reefs at Punta Gruesa as theyare known to be voracious predators. This problem will only worsen unless more efforts

are made to keep the population in check. In the last year numbers have been stable with

around 1 sighting per site visit with the exception of this phase where only 0.6 were

sighted per site visit. The reason for the decrease in numbers is unknown it could be

because lionfish sightings were not recorded, it could also be due the fact that lionfish

killing competitions have been taking place regularly in the nearby town Mahahual, which

would be a very positive sign for the reefs long term sustainability..

According to Morris et al(2010), only 27% of the population needs to be removed monthlyfor the population to decrease. The last phase 11.2% of the lionfish that were recorded

were killed which will hopefully go some way in helping to control the population.


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5. Marine Litter Monitoring Programme.

5.1 Introduction

Punta Gruesas location on the Yucatan Peninsula means that it faces the CaribbeanCurrent. This is a circular current that combined with the Loop current and the Yucatan

current, transports a significant amount of water Northwest ward through the Caribbean

Sea. The main source is from the equatorial Atlantic Ocean via the North Equatorial,

North Brazil and Guiana Currents. Due to the volume of water that is transported and both

the nature and origin of the said currents, it is possible that the litter being found is from

quite far afield. This could be compounded by the high shipping pressures, in particular

the cruise ships that pass through to Mahahual on a regular basis on average carrying

approx. 2-3,000 passengers. Other factors also include outflows from rivers and stormdrains etc. If this is the most common source for the marine debris then it is likely that

weather changes, which have an impact on both tide lines and sea turbulence, will have a

direct and noticeable effect on the amount of rubbish washed up.

Phase 092, April June 2009, saw the beginning of the marine litter collection program at

Punta Gruesa. Marine litter is prevalent along the Caribbean coast and is not only

unsightly but a health hazard to marine life and humans alike. In order to collect more data

on this issue a beach clean program was conducted every phase. This is part of aworldwide program and is just one method of investigation to discover where marine litter

originates from and which materials are most common.

5.2 Aims

This project had three main aims:

Quantified data and photographic evidence as to the extent of marine litter.

Conservation of terrestrial and marine fauna threatened by litter.

Improvement of beach aesthetics.

5.3 Methodology

Marine litter was collected weekly on a 200m stretch of beach north of base. The transect

was cleared one week prior to the commencement of the monitoring program, in order that

only a weekly amount of debris is recorded. Materials were collected from the tide mark to

the vegetation line to eliminate waste created by inland terrestrial sources.


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The waste was separated, weighed and recorded by the categories below:

Fabric

Glass

Plastic

Polystyrene

Metal

Natural material (modified)

Medical waste

Rubber

Rope

Other

5.4 Results

A total of 100.94kg of marine litter was collected this phase across eight beach cleans.

Plastic accounted for 27.4% of the total weight collected. Even though Polystyrene was

one of the smallest categories in terms of weight, in reality it was one of the mostnumerous items and accounts for a large proportion of litter on the transect.

Figure 5-4-1 shows the breakdown of the average litter collected per week since the

survey began in phase 092 (April-June 2009).

Average Rubbish Collected per Week

0

5

10

15

20

092 093 094 101 102 103 104 111 112 113 114

Phase

Weight(kg)

Other

Polystyrene

Medical Waste

Metal

Rope

Natural Material

Rubber

Fabric

Glass

Plastic

Figure 5-4-1 Average Weight of Litter Collected per Week by Phase (Kg)

Since the survey began a total of 847.6kg of rubbish was collected from the beach, 50% of

that was registered as plastic.


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Figure 5-4-2 Breakdown of rubbish collected since 092 to 114 in kg.

5.5 Discussion

As has been the case for the majority of monitors, plastics have again constituted thelargest volume of all the categories this phase. This could be due to its light weight

making it easy to transport and its robustness against degradation. The fact that the level

of plastic found is consistently high from phase to phase is a worrying trend as when

plastics such as Polythene, found in plastic bags, breakdown they form small plastic

particles that can contaminate the food web and be passed on through the trophic levels.

Plastic debris can act like a sponge for toxic chemicals soaking up compounds such as

PCBs and DDE (a product from the breakdown of DDT). Once these are ingested into the

food chain the high concentrations will be spread from organism to organism until thelevels become fatal.

Even though the data shows a large volume of rubbish being collected from a relatively

small section of beach, it may be that the results do not do justice to the actual problem at

hand. This is due to the seagrass bed situated alongside the monitoring area. As

discussed above it is possible that during times of increased wind and wave action the

volume of rubbish collected should show a marked increase. However this could be being

masked by the large quantity of Thalassia testudinum that also gets washed up in thesemore extreme conditions burying the rubbish and hiding it from sight. In some areas the

mound of dead blades can be as much as 75cm deep.


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This phase 28.1kg of waste was categorised as other, which includes materials such as

oil, coal or two materials which were found together which therefore meant they couldnt

be counted separately.


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6. Bird Monitoring Programme

6.1 Introduction

With regard to avi-fauna, Mexico, Central and South America can be divided into threedistinct regions separated by mountain ranges: the Pacific slope, the Interior and the

Atlantic slope. These regions can be further divided into other sub-zones, based on a

variety of habitats.

The Yucatan Peninsula lies on the Atlantic slope and is geographically very different from

the rest of Mexico: it is a low-level limestone shelf on the east coast extending north into

the Caribbean. The vegetation ranges from rainforest in the south to arid scrub

environments in the north. The coastlines are predominantly sandy beaches but alsoinclude extensive networks of mangroves and lagoons, providing a wide variety of habitats

capable of supporting large resident populations of birds.

Due to the strategic location of the Yucatan peninsula, its population of resident breeders

is significantly enlarged by seasonal migrants. There are four different types of migratory

birds: winter visitors migrate south from North America during the winter (August to May);

summer residents live and breed in Mexico but migrate to South America for the winter

months; transient migrants are birds that breed in North America and migrate to SouthAmerica in the winter but stop or pass through Mexico; and pelagic visitors, birds that live

offshore but stop or pass through the region.

Punta Gruesa is located near the town of Mahahual close to the Mexico/Belize border

between a network of mangrove lagoons and the Caribbean Sea. The local area contains

three key ecosystems; wetland, forest and marine environments.

6.2 Aims

Develop a species list for the area

Record the abundance and diversity of bird species. Long-term bird data gathered

over a sustained period could highlight trends not noticeable to short-term surveys.


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Educate the volunteers in bird identification techniques, expanding on their general

identification skills. The birding project also provides a good opportunity to obtain a

better understanding of area diversity and the ecosystem as a whole.

6.3 MethodologyBird monitoring surveys were conducted using a simple methodology based on the bird

monitoring program at Pez Maya. A member of staff accompanied by volunteers monitor

the transects daily between 6 and 8am. There were four transects - Beach south, Beach

north, Road south and Road north. These transects were selected to cover a range of

habitats, including coastline, mangroves, secondary growth and scrub. The transects were

completed in approximately 30 minutes. To reduce duplication of data, recordings were

taken in one direction only which also helps to avoid double-counting where individuals are

very active or numerous. Birds were identified using binoculars, cameras and a range ofidentification books. Identification of calls was also possible for a limited number of

species for experienced observers. If the individual species could not be identified then

birds were recorded to family level.

Each survey recorded the following information; locations, date, start time, end time, name

of recorders and number of each species seen. Wind and cloud cover had also been

recorded to allow consideration of physical parameters.

6.4 Results

A total of 1166 birds were recorded during 41 transects this phase. 54 species were

identified. The only new addition to the species list is the Olive throated Parakeet(Aratinga

nana) (see Appendix VI).

141 Swallow individuals were recorded making up 12.1% of the birds recorded this phase.

Sanderlings (Calidris alba) were the most commonly recorded to species level making up

10.1%. The second most commonly sighted species was the Royal tern (Sterna m.

maxima), which made up 9.0%, followed by the Magnificent frigate bird (Fregata

magnificens), with 6.9% of sightings.


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Figure 6-4-1 Most common bird species or families recorded during phase 114

A total of 13 581 birds were observed since 2009 when the survey began, with the highest

record of 2615 individuals registered on phase 113 (July-September 2011).

A total of 54 species were registered during the time the survey was run. The most

common species recorded was the Great-tailed grackle, followed by the Swallow sps. and

the Tropical mockingbird.


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Figure 6-4-2 Species observed from 092 to 114.


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Table 6-4-1 Most common species recorded since 092 to 114.

Species No. of individuals

Great-tailed Grackle

(Quiscalus mexicanus) 3730Swallow sp. 1660Tropical Mockingbird

(Mimus gilvus) 847Magnificent Frigate

(Fregata magnificens) 812

Sanderling sp. 685Royal Tern (Sterna

maxima) 653Brown Pelican (Pelecanus

occidentalis) 614

6.5 Discussion

Those species with relatively constant numbers across phases are most likely resident in

the area, with only minor fluctuations among those species inclined to local migration for

mating or feeding purposes. Great-tailed grackles, tropical mockingbirds and golden-

fronted woodpeckers all fall into this category, being described as resident breeders

(Howell & Webb 2004). Their numbers have fluctuated but have remained consistently

high.

This phase the great tailed grackle was uncommonly not the highest recorded species.

During previous phases there has never been more than 80 swallows recorded per phase,

until the phase of July-September 2011 when 1346 were recorded. Most of the recorded

swallows were almost exclusively flying South so presumably they were migrating.

According to Howell and Webb (2004) Most species (of swallows) in the (Mexico) region

are at least partial migrants and wintering areas are often not well defined.

Great-tailed grackles and tropical mockingbirds are all resident breeders in the area and

magnificent frigates and brown pelicans are described as common residents (Howell &

Webb, 2004). This explains the constantly high numbers each phase.


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Royal terns, however, are described as being winter (non-breeding) visitors, as are

sanderlings, which were the most common species during Phase 114. Royal terns were

recorded every phase since the survey began, but their numbers were highest during the

winter period

Those species that were observed only at certain times of the year are most likely

seasonal migrants, either moving into the area temporarily or simply moving through the

region on their way to summer or wintering grounds elsewhere. These include the

Sanderlings, plovers, similar species of shore-birds and warblers, many of which are

resident only during the winter, moving further north to breed during the summer.

The species list at Punta Gruesa was constantly expanding each phase as observersbecame more adept at seeing and identifying species and migrant species enter the area.

Starting with 20 species registered when the first survey was done, Punta Gruesa staff and

volunteers accomplished to identify up to 54 different bird species in the area (see

Appendix VI).


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7. Seagrass Monitoring Programme

7.1 Introduction

Phase 102 (April-June 2010) saw the implementation of a new survey program, focusing

on the sea grass beds found adjacent to the beach at Punta Gruesa. The Pta Gruesa

nearby shoreline is dominated by a shallow, almost continuous bed that stretches from the

waters edge to the back reef approximately half a kilometre away. It is characterised by

two main species, Thalassia testudinumand Syringodium filiforme.

The seagrass beds are an intrinsic part of the marine ecosystem providing not only shelter

to juvenile reef fish but also helping to slow the water currents/movement in the lagoon,

decreasing the levels of coastal erosion and providing favourable conditions for both the

mangroves and reefs to grow.

7.2 Aims

The aims of the project were to:

Determine the overall percentage coverage and species composition along three

transect lines and to find out if these values change with proximity to the reef.

Monitor the changes in seagrass coverage and species composition over time.

Monitor the health of the seagrass bed by measuring blade length, predation andepiphyte cover.

7.3 Methodology

In order to monitor the health of this ecosystem, three transects were set up; T1, T2 and

T3 (T1 being closest to the beach and T3 being furthest away). Their positioning was

based on relative distance from the edge of the bed and at a point of change in the

biological composition of the bed.

Table 7-3-1 GPS positions for seagrass transects (Units in WGS 84 Format hddd.dddddo

)

T1A 19.00810087.58933

T1B 19.00790087.58941

T1C 19.00770087.58949

T2A 19.00785087.58875

T2B 19.00765087.58883

T2C 19.00744087.58889

T3A 19.00748087.58767

T3B 19.00724087.58772

T3C 19.00703087.58779


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Starting at point T1A (the most northerly point) a 1mx1m quadrat was laid on the shore

side of the transect line and the following measurements were taken;

Overall percentage cover.

S. filiformepercentage cover.

T. testudinumpercentage cover

On 20 random T. testudinumblades within each quadrat, blade length, signs of

predation (yes or no) and percentage cover of epiphytes was recorded.

This was repeated at 5m intervals across the length of each transect giving ten repeats per

transect.

This methodology allows a rapid assessment of an otherwise uncharted area of seagrass

in the Punta Gruesa area. Due to the fact that they play such a crucial ecological role in

the health of the reef systems, as a result of the habitual symbiosis shared between

seagrass beds, reefs and mangroves, it is important to monitor and assess the seagrass

beds.

This methodology enabled GVI Mexico to obtain baseline data on the species composition,percentage cover and condition so that changes in the health and structure can be

monitored over an extended period of time. The methodology is based on the

methodology of seagrassnet.com (Short et al. 2006) with slight modifications to

accommodate for volunteers with limited training.

7.4 Results

The average percentage cover of seagrass was found to be highest on the transect

closest to the beach: transect 1 had 74.0% cover, transect 2 had 65.5% cover and transect

3 had 36.8% cover.

Average T. testudinumcover is highest on the transect closest to the beach: transect 1 had

61.0% cover, transect 2 had 37.0% cover and transect 3 had 28.2% cover. T. testudinum

was the dominant species on all three transects.


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Average blade length ofT. testudinum was found to be shortest on the transect furthest

from the beach. On transect 1 it was found to be 12.9m, on transect 2 it was 16.7cm and

on transect 3 it was 7.7cm.

7.5 Discussion

T. testudinum has been found to be the more dominant species on all three transects

every time the survey has been carried out. Williams (1987) observed a decline in S.

filiforme shoot density as T. testudinum became dominant during temporal development

and found that this was a result of exploitative competition primarily for sediment nutrients

but also light. T. testudinum has a much greater leaf area for inception of light than S.

filiforme. For example, a typical leaf width forT. testudinum is 1cm in contrast to just over

1mm forS. filiforme.

Each time the transects were monitored, the T. testudinum on transect 3 (closest to the

reef) has been found to have the shortest average blade length and the T. testudinumon

transect 2 was found to have the longest blade length. Sweatman and Robertson (1994)

found that T. testudinum provided minimal cover (for juvenile fish) near to the reef edge

because the blades were grazed short. They found that blade length increased with

distance from the reef edge. This could partially explain the pattern observed here.

Average percentage cover of seagrass is highest on transect 1, which is closest to the

beach, and lowest on transect 3, which is closest to the reef. This is due to a drop in T.

testudinum cover. Sweatman & Robertson (1994) found that T. testudinumblade density

was similar at all of their sample distances from the reef. It is possible that the density

across the three transects at Punta Gruesa may be similar. There may appear to be a

difference in percentage cover due to differences in average blade length discussed

above.


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8. Summary

This is the last report produced with the data gathered in Punta Gruesa from January 2008

to December 2011. Due to different reasons the project will no longer be continued. During

the time Punta Gruesa was running different sets of data were collected and analysed,

some of the results were:

*550 coral transects and 900 fish transects were done from January 2008 to December

2011.

* The average coral cover over all phases was 10.46% while the macro algae cover was

66.34%.

*Las Delicias (LD) was the site with the lowest coral cover (7.21%) while Las Joyas (LJ)

registered the highest (14.84%).

*The most common species of coral registered was Agaricia agaricites.

* Only 5.2% of the colonies studied were suffering disease; the main disease was dark

spot.

*Sponge predation accounted for the majority of the records of predation on coral colonies.

* 30.39% of the colonies studied on the coral communities survey presented bleaching,

with Siderastrea sidereaas the most common (generally with pale bleaching).

* The highest numbers of colonies with bleaching where recorded during the last quarter of

the year (October-December) with the exception of 2010 where the highest numbers were

registered during the third quarter (July-September)

*13,148 adult fish and 12,611 juvenile fish were recorded.

* The average biomass registered from January 2008 to December 2011 was 3.87 kg 100

m-2

*Haemulidae was the most commonly recorded family over all phases, with 50.86% of the

total number observed.

* Stegastes partituswas, on average, the most abundant juvenile species recorded.

*More than 250 children and adults received English lessons and Environmental

Education. Punta Gruesa staff and volunteers participated in activities in town like the

annual Beach clean on the International Clean up day, Project Aware Dive into Earth Day

celebration, Jatsa Ha Festival, Mahahual Carnival, etc.


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* 2429 incidental sightings were registered, from those 304 were turtles, 1140

Elasmobranchs, 382 eels and 603 dolphins. The most common species were the

Hawksbill turtle, the Southern stingray, the Spotted moray and the Bottlenose dolphin.

* 1380 lionfish were recorded; the most abundant size was 16-20cm.

* 847.6kg of rubbish was collected on 72 beach cleans, with plastic as the most commoncategory registered.

*A total of 13581 birds were identified on 54 different species, the most common one was

the Great-tailed grackle (Quiscalus mexicanus).

Thank you very much to all the volunteers and the staff that made this work possible. All

the data gathered has been given to our local partners Amigos de Sian Kaan who will

continue with further analysis and implementation of the conclusions gathered from the

monitoring effort.


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9. References

AGRRA (2005) Atlantic and Gulf Rapid Reef Assessment (AGRRA) Field Guide to

Indicators of Coral Reef Health

AGRRA (2000) Atlantic and Gulf Rapid Reef Assessment (AGRRA). The AGRRA Rapid

Assessment Protocol.http://www.agrra.org/method/methodhome.htm

Almada-Villela P.C., Sale P.F., Gold-Bouchot G. Kjerfve B. (2003) Manual of Methods for

the MBRS Synoptic Monitoring System: Selected Methods for Monitoring Physical and

Biological Parameters for Use in the Mesoamerican Region. Mesoamerican Barrier Reef

Systems Project (MBRS).

Deloach, N. and Humann, P. (1999) Reef fish behaviour: Florida, Caribbean, Bahamas.

New World Publications. Artegrafica. Verona, Italy.

Franklin, J. L. (2008) Tropical Cyclone Report: Hurricane Dean. National Hurricane Centre

http://www.nhc.noaa.gov/pdf/TCR-AL042007_Dean.pdf

Gardener, T.A., Cote, I.M., Gill, J.A., Grant, A., Watkinson, A.R. (2003) Long-term region-

wide declines in Caribbean corals. Science 301: 958-960.

Howell, S. N. G., and Webb, S. (2004) A Guide to the Birds of Mexico and Northern

Central America. Oxford University Press Inc., New York

Morris, J. A. Jr., Shertzer, K.W., Rice, J.A. (2010) A Stage-Based Matrix Population Model

of Invasive Lionfish with Implications for Control. Biol Invasions, DOI10.1007/s10530-010-

9786-8

McClanahan, T.R., Muthiga, N.A. (1998) An ecological shift in a remote coral atoll of Belize

over 25 years. Environmental Conservation25: 122-130.
http://www.agrra.org/method/methodhome.htmhttp://www.agrra.org/method/methodhome.htmhttp://www.agrra.org/method/methodhome.htmhttp://www.nhc.noaa.gov/pdf/TCR-AL042007_Dean.pdfhttp://www.nhc.noaa.gov/pdf/TCR-AL042007_Dean.pdfhttp://www.nhc.noaa.gov/pdf/TCR-AL042007_Dean.pdfhttp://www.agrra.org/method/methodhome.htm


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Rogers, C. S. and Miller, J. (2006) Permanent phase shifts or reversible declines in coral

cover? Lack of recovery of two coral reefs in St John, US Virgin Islands. Marine Ecology

Progress Series306: 103-14

Short, F.T., McKenzie, L.J., Coles, R.G., Vidler, K.P., Gaeckle, J.L. (2006) SeagrassNetManual for Scientific Monitoring of Seagrass Habitat, Worldwide edition. University of New

Hampshire Publication. 75 pp.

Spalding, M.D., Jarvis, G.E. (2002). The impact of the 1998 coral mortality on reef fish

communities in the Seychelles. Marine Pollution Bulletin44: 309-321.

Sweatman, H. & Robertson, D. R. (1994) Grazing halos and predation on juvenile

Caribbean surgeonfishes. Marine Ecology Progress Series. Volume 111: 1-6

UNEP-WCMC (2006). In the front line: shoreline protection and other ecosystem services

from mangroves and coral reefs. UNEP-WCMC, Cambridge, UK.

Wilkinson, C. (2008) Status of Coral Reefs of the World: 2008. Global Coral Reef

Monitoring Network and Reef and Rainforest Research Centre, Townsville, Australia

Williams, S. L. (1987) Competition between the seagrasses Thalassia testudinum andSyringodium filiforme in a Caribbean lagoon. Marine Ecology Progress Series. Volume 35:

91-98


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10. Appendices

Appendix I SMP Methodology Outlines

Buddy method 1: Surveys of corals, algae and other sessile organisms

At each monitoring site five replicate 30m transect lines are deployed randomly within

100m of the GPS point. The transect line is laid across the reef surface at a constant

depth, usually perpendicular to the reef slope.

The first diver of this monitoring buddy pair collects data on the characterisation of the

coral community under the transect line. Swimming along the transect line the diver

identifies, to species level, each hermatypic coral directly underneath the transect that is atleast 10cm at its widest point and in the original growth position. If a colony has been

knocked or has fallen over, it is only recorded if it has become reattached to the

substratum. The diver also records the water depth at the beginning and end of each

transect.

The diver then identifies the colony boundaries based on verifiable connective or common

skeleton. Using a measuring pole, the colonies projected diameter (live plus dead areas)

in plan view and maximum height (live plus dead areas) from the base of the coloniessubstratum are measured.

From plane view perspective, the percentage of coral that is not healthy (separated into

old dead and recent dead) is also estimated.

The first diver also notes any cause of mortality including diseases, predation and any

bleached tissue present. The diseases are characterised using the following categories:

Black band disease Red band disease

White band disease Hyperplasm and Neoplasm (irregular growths)

White plague Dark spot disease

Yellow blotch disease Unknown

Dark spot disease


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Predation and overgrowth are also recorded on each of the coral colonies. The following

categories are considered:

Parrotfish predation Fire coral predation

Damselfish predation Gorgonian overgrowth

Fireworm predation Zoanthid overgrowth

Short coral snail predation Coralline algae overgrowth

Overgrowing mat tunicate Sponge overgrowth

Variable boring sponge Cliona sp.

Bleaching is described as either pale, partial of total using the following definitions:

Pale the majority of the colony is pale compared to the original colour of the coral

Partial the colony has a significant amount of patchy white areas

Total all, or almost all, of the colony is white

Any other features of note are also recorded, including, orange icing sponge, coralcompetition and Christmas tree worms.

The second diver measures the percentage cover of sessile organisms and substrate

along the 30m transect, recording the nature of the substrate or organism directly every

25cm along the transect. Organisms are classified into the following groups:

Coralline algae - crusts or finely branched algae that are hard (calcareous)

Turf algae - may look fleshy and/or filamentous but do not rise more than 1cm above the

substrate

Macroalgae - include fleshy and calcareous algae whose fronds are projected more than

1cm above the substrate. Three of these are further classified into additional groups which

include Halimeda, Dictyota, and Lobophora

Gorgonians

Hermatypic corals - to species level, where possible

Bare rock, sand and rubble

Any other sessile organisms e.g. sponges, tunicates, zoanthids and hydroids.


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Buddy method 2: Belt transect counts for coral reef fish

At each monitoring site 8 replicate 30m transects lines are deployed randomly within 100m

of the GPS point. The transect line is laid just above the reef surface at a constant depth,usually perpendicular to the reef slope. The first diver is responsible for swimming slowly

along the transect line identifying, counting and estimating the sizes of specific indicator

fish species in their adult phase. The diver visually estimates a two metre by two metre

corridor and carries a one meter T-bar divided into 10cm graduations to aid the accuracy

of the size estimation of the fish identified. The fish are assigned to the following size

categories:

0-5cm 21-30cm6-10cm 31-40cm

11-20cm >40cm (with size specified)

The buddy pair then waits for three minutes at a short distance from the end of the

transect line before proceeding. This allows juvenile fish to return to their original positions

before they were potentially scared off by the divers during the adult transect. The second

diver swims slowly back along the transect surveying a one metre by one metre corridor

and identifying and counting the presence of newly settled fish of the target species. Inaddition, it is also this divers responsibility to identify and count the Banded Shrimp,

Stenopus

gvi mexico punta gruesa september-december 2011 and 2008-2011 summary report

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