Many fishing techniques and practices are destructive to the marine environment causing overfishing, massive by-catch, damage to the sea bottom and coral reefs, and ghost fishing.
Trawling and the use of gill-nets, purse seine and FADs (Fish Aggregating Devices) are some problematic fishing techniques that create ghost nets.
Pole and line, the primary fishing technique in the Maldives, is a low impact and sustainable fishing technique.
Gill-nets are the dominant gear in the Indian Ocean. Gill-nets are used in artisanal and semi-industrial fisheries, contributing to 30-40% of the total catch.
The net design is comprised of continuous panels of uniform mesh size, aimed to trap fish behind the gills.
The International Sustainable Seafood Foundation (ISSF) notes that rates of sharks and turtle by-catch in Indian Ocean gill-net fisheries are high.
Trawling involves dragging a fishing net behind a boat, either mid-water or on the bottom. By-catch is extremely high and nets are often lost due to snagging on the bottom. Trawling is a common fishing technique in India and Sri Lanka.
Purse seine nets involve a long wall of netting that can surround a school of fish and be pulled tight, enveloping the school of fish (and any other animals) in a purse-like structure.
Purse seiners are usually used to catch pelagic tuna, especially in the western Indian Ocean. They are often used in association with FADs (see below).
Fish Aggregating Devices (FADs)
All floating objects, be they natural or man-made, attract aggregations of fish underneath them. FADs are man-made objects (usually a square of bamboo with netting and buoys attached, sometimes with a solar-powered GPS tracker onboard to allow the boat that deployed it to track it) used to improve a vessel’s catch by attracting fish beneath them. FADs can be static or deployed in the open ocean as drifting devices (dFADs). The International Sustainable Seafood Foundation (ISSF) has encouraged the use of net-free non-entangling FADs in the Indian Ocean.
Numerous dFADs have been found drifting in Maldivian waters. Some have even been traced back to specific boats operating in the Western Indian Ocean. The below images are examples of dFads found in the Maldives. Photos © Olive Ridley Project (right) and © Guy Stevens|Manta Trust (left).
Pole and Line
Pole and Line is a sustainable fishing technique used primarily in the Maldives, that involves using live bait to attract larger tuna. They are caught using a pole with a line and barb-less hook on the end. By-catch is virtually eliminated.