Say No To Bottom Trawling: A Damaging & Wasteful Fishing Technique
Bottom Trawling: How Does It Impact The Environment?
Bottom trawling is a fishing technique whereby the net is towed along the seafloor to trap and catch fish. The net can be anywhere in the water column of the ocean, including the midwater or bottom sections. Over 30 million tonnes of fish and marine invertebrates are caught each year by bottom trawling. The following describes how the techniques affect the environment (source: worldatlas):
1. Bottom Trawling Leads to Overfishing
The technique causes large numbers of fish to be caught as trawl nets are usually very large and trawlers move these nets across long distances. The intensity of the works can rapidly deplete fish stocks, and in the long run, overfishing may also lead to the elimination of fish species altogether.
2. Unwanted Marine Life Caught as “Bycatch”
Bottom trawling causes ‘bycatch’ (the unwanted catch). The fishing nets used in bottom trawling are unable to distinguish between species, and therefore many species of fish, marine invertebrates, marine mammals, reptiles, and even seabirds are caught in such nets. Today, bycatch is one of the primary reasons for the deaths of millions of dolphins, sharks, whales, and other marine fauna, and has pushed many species to the brink of extinction.
Bottom Trawling Destabilises the Seafloor
The seafloor is a very stable system. It is the calmest part of the sea, where currents, temperature, and other natural conditions remain relatively undisturbed. However, when heavy nets are dragged along the seafloor, they stir up sediments as well as the water, resulting in a destabilization of the seafloor.
4. Marine Flora and Fauna Living on the Ocean Floor Die
Bottom trawling operations uproot and displace marine flora and fauna living on the ocean floor. Sea anemones, sea pens, sponges, urchins, and other fragile-bodied marine fauna are destroyed during the trawling process. The destruction of such corals, for example, adversely affects species which are dependent on them.
5. Bottom Trawling Puts the Livelihoods of Local Fishing Industries at Stake
Bottom trawling requires sophisticated technology, and is highly profitable. Therefore, large companies compete with each other to gain control of the sea areas that are rich in fish. Often, in order to maximize profits, the winner ensures that no other competitors can fish in these areas. Local fishing businesses with traditional fishing equipment and small boats thus cannot compete with large fishing companies, and are therefore squeezed out and suffer economic losses.