IUCN recently declared that fishing is one of the biggest threats to marine animals. Not only is the unrestricted fishing in world oceans causing mass populations of fishes to eradicate, it is also indirectly harming the ecosystem and leading many big and small species to death. One of the fishing practices adopted by Indian fisherman called bottom trawling is only making the situation even worse.
What is Bottom Trawling?
Trawl is a kind of fishing net. In the bottom trawling method of fishing, the trawl is towed along the bottom of the sea by fixing two heavy metals on the mouth of the bottom trawl net. The fishermen drag the net on the sea floor in such a way that many fishes especially shrimps are caught in the nets.
It is a method mainly used to catch prawns and demersal fish like groupers that roam near the water column just above the seabed. It is also used to catch sea cucumbers and pearl oysters.
The Threat
Bottom trawling is frequently used by fishermen in the Palk Bay which is bounded on the north and west by the coastline of the State of Tamil Nadu and the east by the northeast coastline and the Jaffna peninsula of Sri Lanka. Sri Lankan government has frequently found Indian fishermen trespassing beyond the international boundaries to catch fish this way.
The method has already depleted number of shrimps, prawns and sea cucumbers in vast numbers. The problem is aggravated for sea cucumbers because unlike fishes they are slow breeders and therefore their population is under grave threat of wiping out suddenly.
Besides the direct catch, bottom trawling also results in indirect mortalities in the sea.
Endangered marine turtles and other creatures that do not have a commercial value are unavoidable by-catch victims of Bottom Trawling. When the net drags, it also disturbs the underwater sediments and thousands of little creatures that find refuge in the soft sands are exposed to predators.
“Operating a Bottom-trawling underwater is like running a bulldozer across the Sinharaja Rainforest,” said Sri Lankan marine biologist Nishan Perera.
Organisations like greenpeace also have pointed out the drastic effects of this method and advise placing huge rocks at strategic locations inside the oceans to discourage the use of this method.
While the Indian side of the Gulf of Mannar has already been declared as a Man and Biosphere (MAB) Reserve by UNESCO it is hardly stopping fisherman from using the bottom trawling method to catch fish beyond the Indian boundaries and thereby threatening the complete fragile ecosystem of the area. If stricter measures are not put into place, the world may soon lose one of the most bio diverse marine habitats.
-Atula Gupta
Article reference: Sundaytimes
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