gulf of mannar
TRANSCRIPT
Presentation by
Livi Wilson
Ph.D Scholar
Biodiversity of Gulf of Mannar
Gulf of Mannar large shallow bay
lies between the southeastern tip of India and the west coast of Sri Lanka.
The estuaries of Thamirabarani River of south India and the Aruvi Aru River of Sri Lanka drain into the Gulf.
GEOGRAPHICAL LOCATION
Palk Strait
Palk Bay
Adam’s Bridge
Gulf of Mannar
About gulf of mannarSome features:1986- declared the Gulf of Mannar Marine National Park.
1989-The park and its 10 km buffer zone were declared a Biosphere Reserve
First marine Biosphere Reserve in South East Asia, a chain of 21 islands (10,500 km²)
Home to 3,600 rare Species of flora and fauna like fishes, coral reefs, sea horse, algae, marine plants
The islets and coastal buffer zone includes BeachesEstuaries Tropical dry broadleaf forests
The marine environments include Seaweed communities Sea grass communities Coral reefs Salt marshes Mangrove forests
Gulf of Mannar reefs lie along the 140 km stretch between Tuticorin
and Rameswaram latitude 8°47' N and 9° 15' N longitude 78° 12' E and 79° 14'E. Mannar Barrier reef which is about 140 km
long and 25 km wide between Pamban and Tuticorin
The islands have fringing coral reefs and patch reefs around them
Total area occupied by reef and its associated features is 94.3 sq km.
Reef diversity and resources
96 species of corals belonging to 36 genera
The most commonly occurring genera of corals are Acropora, Montipora and Porites.
the reefs also harbour boring sponges, molluscs, worms, echinoderms, common shrimps, and fish
ornamental fishes belonging to the family Chaetodontidae,(butterfly fish); Amphiprion spp (clown fish), Holocentrus spp (squirrel fish), Scarus spp (parrot fish), Lutjanus spp (snapper fish) and Abudefduf saxatilis (sergeant Major) are abundant. (Kumaraguru, 1997).
Extensive sea grass beds are present; green turtles, olive ridleyturtles and dugongs are dependent on the sea grasses.
A unique endemic species of Balanoglossus, a living fossil that is considered a link between vertebrates and invertebrates was recorded from this region.
Annual productivity in coral reefsbeing 2000-5000 gc/sq.m/yr.
Sea Grass Ecosystem
the sole marine
representatives of the
Angiospermae
feeding grounds of the
herbivores Green Turtle
and the sea cow
Sea grass binds
sediments and prevent
erosion.
Of the 52 species of sea
grasses recorded
worldwide, 12 species
are recorded in Gulf of
Mannar.
Sea grasses absorb
sediments thereby
Mangrove Ecosystem
salt tolerant forest ecosystems, which support
fisheries and protect the coastal zones, thus
helping the marine coastal economy and
environment.
9 species and 7 associated species were found in
Gulf of Mannar.
The two common mangrove species Rhizopora
sp and Avecinia sp.
Dolphins are a common in some parts of the Gulf.
Thousands of migratory olive ridley sea turtles pass through the Gulf to their mass nesting or arribada in Gahirmatha Orrisa.
The Krusadai Island in the Mandapam Group of islands is of biological significance in this area due to its diversity.
due to destructive fishing and pollution, coral reefs, dolphins, Dugongs (Dugong Dugon), whales and sea cucumbers are among the species which figure in the endangered list
Overall diversity
Families Species
Phytoplankton 126Zooplankton 360Forominifera 51Sponges 275Corals 128Gorgonids 14Polochaeta 75Nematoda 9Crustacea 368Molluscus 731Echinodermata 264Hemichordata 1Capture fishes 441Ornamental fishes 100Sea turtles 5Sea weed 147Sea grass 52Mangroves 16
Fishery Resources
Marine capture fisheries are the major economic
activity in Gulf of Mannar
441 species have been recorded in Gulf of
Mannar.(2,200 fish species distributed in Indian
waters)
Gulf of Mannar is one of the best regions in the
Indian subcontinent in fish biodiversity richness.
Shore seines, boat seines, trawl nets and hook
lines are the principal gear operated.
Setusamudram
Advantage
s1.Saving of upto 30 hours or 424 nautical miles
2. Considerable savings to vessels and earnings of foreign exchange.
3. Beneficial for naval defence4. Increased economic activities like
transportation, fishing and ancillary industries
5. Augmentation of external infrastructure like road/rail, water & water supply
6. A stable system with least maintenance cost
Environmental Aspect
Some of the flora and fauna of this region
Extinction of more than 700 fish
varities
More susceptible to future cyclone and
tsunamis
Disastrous effect on marine life,
fisheries, virgin beaches in case of an
accident
Whether to go for short term financial
gains or long term ecological balance
?
Biodiversity of the Gulf Of Kutch
The Gulf of Kutch is situated in Saurashtra in the western State of Gujarat in India.
separates the landmass of Saurashtra from the northern landmass of Kutch.
shallow water basin about 60 m deep at the mouth, sloping up to a depth of less than 20 m at the head, visited by 'mixed semidiurnal' tides
Gulf of Kutch Marine National Park
It is the first national marine park in India.
situated on the southern shore of the Gulf of Kutch in the Jamnagar District of Gujarat state.
1980-an area of 270 km2, from Okhato Jodiya was declared Marine Sanctuary.
1982-a core area of 110 km2 was declared Marine National Park under the provisions of the Wildlife (protection) Act(1972)
Contd..
Protected areas include about an archipelago made up of
42 islands.
fauna found here: coral, dugong and the finless porpoise.
Biodiversity and Conservation challenges:
extraction of corals and sands by cement industries,
increased turbidity of water, oil refineries, chemical
industries and mechanized fishing boats.
Biodiversity Excellent Coral Reefs 37 species of Hard & Soft Corals 70 species of Sponges 27 species of Prawns 30 species of Crabs 200 species of Molluscs Endangered Sea Turtles like the Green Sea, Oliver
Riddley& Leather Back. 3 Speices of Sea Mammals 94 species of Water Birds 78 species of terrestrial birds 108 species of brown, green & red Algae
Coral Reefs fringing reefs, platform reefs, patch reefs and
coral pinnacles. There are some 40 islands with patchy coral
formation of which the largest is Pirotan Island. 37 species of hard corals 12 species of soft corals the total reef area in the Gulf decreased from
217 sq km in 1975 to 123 sq km in 1986; a net loss of 43 per cent
Coral dredging by a cement company is held to be largely responsible for the heavy siltation
Locality Genera species
Gulf of Kutch* 24 37
West Coast Patches* 17 29
Lakshadweep Islands 37 103
Palk bay and Gulf of
Mannar
36 96
Tuticorin 19 21
Andaman Islands 31 82
Nicobar Islands 43 103Total for India* 37
199
Source: Bakus, G.J (1994) and * Pillai, G (1996).coral
Mangroves Jamnagar District has an area of 665.9 sq km
mangrove cover
predominantly of scrubby and sparse type
Mangrove species such as Rhizophora, Ceriops
and Aegiceros, which are reported to have once
existed in the region, are now rare, while the
species Bruguiera is extinct
Since the early 1990s, mangrove cover has been
increasing in Gujarat, from 397 sq km in1991 to
960 sq km in 2003.
- Jamnagar and Kutch - contributed to more than
90 per cent of the overall increase in mangrove
cover.
Fisheries Jamnagar contributed 10.01 per cent of the total marine
fish production in the State.
W. Pomfret
B. Pomfret
Bom. Duck
Thread fin
Jew fish
Hilsa
Clupeids
Coilia
Shark
Malabar upwelling
Upwelling occur where the wind blows parallel to a coastline.
divergence draws water from below into the surface Ekman layer in a process known as upwelling
Upwelling in coastal waters brings nutrients toward the surface.
Phytoplankton reproduce rapidly in these conditions, and grazing zooplankton also multiply and provide abundant food supplies for nekton.
Some of the world’s richest fisheries are found in regions of upwelling—for example, the temperate waters off Peru
Upwelling in these regions cools the surface
water and brings nutrient-rich subsurface water
into the sunlit layer of the ocean, resulting in a
biologically productive region.
The Malabar upwelling zone along Kerala coast
(south-west coast of India) is one of the important
upwelling systems of the world (Bakun et al.,
1998)
The Malabar coast of India is rich in primary (660
mg C m2/ day) and secondary (10–57 mgC m2
/day) production and contributes nearly 50% of
the total Indian marine fish landings
(Vivekanandan et al., 2003; Smith and
Madhupratap, 2005)
Field and satellite-derived oceanographic data
have shown that coastal upwelling occurs during
July–September with a peak in August resulting in
high nutrient concentrations and biological
productivity along the coast.
The striking feature of the Malabar upwelling
zone is the predominance of pelagic resources
such as oil sardine (Sardinella longiceps) and
Indian mackerel (Rastrelliger kanagurta)
The catch of small pelagics, especially that of the oilsardineincreased from1, 554 t in 1994 to 2,50, 469 t in 2007 in the Malabar upwelling zone off Kerala, India.
The coastal upwelling index (CUI) during south-west monsoon increased by nearly 50% during the period 1998 to 2007.
This substantial increase in coastal upwelling index elevated chlorophyll a concentration during monsoon which resulted in an increase of over 200% in annual average chlorophyll a concentration.
The increasing coastal upwelling index and chlorophyll a during monsoon sustained an increasing catch of oilsardineduring postmonsoon season.
The responses of lesser sardine and Indian mackerel, which are midlevel carnivores, were different.
The prawn fishery is supported chiefly by
Melapenaeus dobsoni (Poovalan chemmeen).
Parapenaeopsis stylifera (Karikkadi chemmeen)
and Penaeus indicus (Naaran chemmeen) also
occur in smaller quantities.
In the case of M. dobsoni, sizes ranging between
90-105 mm dominate in the fishery.
References Influence of coastal upwelling on the fishery of small pelagics off
Kerala, south-west coast of India
U. MANJUSHA, J. JAYASANKAR, R. REMYA, T. V. AMBROSE AND E. VIVEKANANDAN
The Gulf of Kutch Marine National Park and Sanctuary: A Case Study By Nilanjana Biswas
Coastal an marine wetlands of India by K.Venkataraman
Resources information system for Gulf of MannarGovernment of India
Environmental Impact Assessment for Proposed SethusamudramShip Canal Project Tuticorin Port Trust