Dugongs, Sea Horses and mangroves, all play their part in Gulf of Mannar being a Marine Biosphere Reserve.
The Gulf of Mannar Biosphere Reserve - a world treasure
The Gulf of Mannar is the biologically richest coastal region in
India with 3,600 species of plants and animals known to live within
its boundaries. In the Gulf of Mannar you can still see the
globally endangered dugong, several species of dolphins and whales
and three species of endangered sea turtles. Furthermore, the
Reserve is home to sea horses, 450 species of fish, hundreds of
species of sea cucumbers, sponges, all kinds of corals and species
of sea grass found nowhere else. In addition more than 150 species
of bird are found on islands in the reserve. Vital to the ecology
of the reserve are the 17 species of mangrove which act as
important fish nurseries.
The reserve covers 10,500 sq. km and has 21 islands with
continuous stretches of coral reef. The core area of the reserve is
comprised of a 560 km2 core area of coral islands and shallow
Commercial fishing is done in about 5,500 sq. km. and nearly
50,000 people dwelling in 47 villages along the coastline bordering
the Gulf of Mannar depend directly on the natural resources of the
Biosphere reserve for their livelihood.
The Reserve's fishery is dominated by fish species like lesser
sardine, silver belly, mackerel, anchovy, thread fin, bream,
lobster, molluscs and prawns.
Threats to the Gulf of Mannar Biosphere Reserve
The fragile Coral reefs and the unique flora including Sea
Grasses of Gulf of Mannar, which provide homes to an abundance of
marine creatures, are under multiple threats.
Destructive coastal development
The most direct threat to the Marine Reserve is the proposed
Sethu Samudram Canal on the coast of Tamil Nadu. The canal
threatens to destroy the near pristine Gulf of Mannar Biosphere
The construction of the canal will destroy the unique and
fragile marine ecology of the area through constant dredging to
maintain a canal depth of about 10 m. Aside from the immediate
destruction of the sea bed, the consistent churning of sediment
will smother the coral reefs adjacent to the canal. The increase in
shipping traffic will inevitably result in an increase in oil
spills and marine pollution.
Untreated Chemical effluents, including vast quantities of
mercury and dumping of fly ash from the industries and thermal
power plant in Tuticorin are the biggest threat to the health of
the marine reserve
The dumping of fly ash slurry into the Karapad bay by the
thermal power station has resulted not only in filling up of an
extensive portion of the Bay, but also fly ash entering the sea
directly. The ash, on being carried far into the sea has caused
irreversible and extensive damage to the sedimentary organisms,
algal beds, chank (Indian conch), pearl oysters and to all the
corals and associated creatures. Mangroves, which grow on the
margin of the shoreline, have accumulated alarmingly high levels of
ash borne minerals.
The increase in the number of mechanized fishing vessels using
bottom trawls results in physical damage to the fragile corals -
the heavy trawl gear breaking off branches and destroying fragile
structures that have taken many years to grow. In addition, large
numbers of juvenile fish and other marine species are taken in the
fine mesh nets as bycatch. Sea grass beds which act as important
spawning and nursery grounds for many fish species are also harmed
by inappropriate bottom trawling practices.
Also the increased numbers of larger mechanized boats that catch
most of the fish threatens the livelihoods of artisan fishermen.
Mechanized boats use multi-gear systems such as fish trawls, pair
trawls (illegal), drift nets, gill nets and bottom set gill nets.
Smaller, traditional motorized and non-motorized boats use bag
nets, purse seines, gill nets, trammel nets, and hook and line
set-ups. The on-going mechanization of the fishery has displaced
traditional fishermen and women, forcing them to take up the
harvesting of wild seaweed or coral, which has now reached a point
More and more coral mining takes place in the southern part of
the Gulf of Mannar Biosphere Reserve. It has stripped most of one
island's coral and threatens to do the same in other parts of the
As the local fishermen cannot catch enough fish anymore, they
are forced them to take up other destructive practices such as
mangrove cutting and coral mining in and around the park, that are
locally used as nutritional supplements, souvenirs and