Friday, April 23, 2010

IMACT OF GLOBAL TRAWLING ON MARINE DIVERSITY

TRAWLING IS THE DRAGGING OF WEIGHTED NETS ACROSS THE SEA FLOOR TO CATCH SHRIMP AND BOTTOM DWELLING FISHES SUCH AS FLOUNDER. IT IS A MAJOR SOURCE OF PRESSURE ON THE BIODIVERSITY OF THE COASTAL ECOSYSTEM. MODERN TRAWLING DEPLETES TARGETED FISH STOCKS. WHAT IS WORSE, IT DAMAGES  OR DESTROYS NON TARGETED SPECIES, INCLUDING CORALS AND SPONGES THAT MAY TAKE YEAR TO RECOVER.


TRAWLING IS AN ENVIRONMENT CONCERN AS IT LACKS SELECTIVELY AND PHYSICALLY DAMAGES THE SEA LAND.

THE THICK NATURAL CARPET OF BOTTOM-DWELLING PLANTS AND ANIMALS IS IMPORTANT FOR THE SURVIVAL OF MANY FISH SPECIES. THUS, THE DESTRUCTION OF SEA FLOOR HABITATS IN HEAVILY TRAWLED AREAS LEADS TO THE DECLINE OF THE FISHING STOCKS.

MORE AND MORE TRAWLERS ARE MOVING BEYOND THE CONTINENTAL SHELF, EXPANDING INTO AREAS THAT PREVIOUSLY WERE NOT SWEPT BY TRAWLERS. DEEP-SEA SPECIES GROW MORE SLOWLY THAN SHALLOW WATER SPECIES. HENCE THE LONG TERM IMPACT OF THIS PRACTICE IS MAGNIFIED AS TRAWLING DEPTH INCREASES.

SOME MARINE ECOLOGISTS HAVE COMPARED THE IMPACT OF TRAWLING ON THE BIOLOGY OF THE SEAFLOOR TO THAT OF CLEAR-CUTTING ON FOREST ECOSYSTEMS.

THE TORTOISE ARE GETTING KILLED DUE TO THE TRAWLING.







VARIOUS UNDERWATER PLANT AND ANIMAL SPECIES ARE GETTING DAMAGED DUE TO THIS TRAWLING  AND MANY OF THEM ARE ALREADY BECOME EXTINCT.