Bottom Trawling: Deforestation of the Ocean

        The diversity and density of species on the ocean floor is being threatened more than ever and humans are to blame. The use of bottom trawls on the ocean floor effectively clears out large areas of the ocean floor in a matter of minutes. The species I have covered in my previous blogs: sea stars, sand dollars and squids are all currently being harmed by these over fishing methods. They are not the only animals harmed by bottom trawling, pretty much any species whose niche lies at the ocean floor is in danger. Probably the worst thing about bottom trawling is that many of the aquatic life captured are not kept, but they are thrown back with damages beyond repair. To understand its impact we first must understand how bottom trawling works and what is actually used for.

   

Lophelia pertusa reef reduced to almost nothing after being trawled. Images courtesy of Fisheries and Oceans Canada/Peches et Oceans Canada

         Bottom trawls are made up of large nets that are weighed down by heavy weights that can way up to several tons. The net is kept open with small buoys above the weights, this creates an opening at one end of the net while the back is also weighted down and closed. The trawl is then dragged by a fisherman’s boat with the open end facing the boat. The boat drags the open end around the sea floor picking up everything, even things fishermen are uninterested like corals. Fisherman mostly use bottom trawls to catch shrimp, cod, sole and flounder but destroy the ocean floors ecosystem in the process. Just to drive the point home let us reiterate the destructiveness of bottom trawling. ( A detailed look on what a bottom trawl is)

 

 BY PRODUCT:

 

Source: Brian Skerry, ocean soul

        

 Bottom trawling is a very unselective mean of fishing, taking many fish other than the desired fish. The bycatch, fish caught by mistake, of bottom trawls is about 90% of the trawl. Bottom trawling also digs into the ocean floor breaking loose sediment and mud that spreads like clouds over the surface of the ocean, which inhibits the absorption of light by the aquatic life that need it. This spread of mud that follows bottom trawling can be seen from satellite images by scientists. There is good news on this subject though and that is that there is action being taken against it. The studies by marine biologists have led to restrictions against the destructive fishing. The United Nations General assembly has started to put an end to trawling in  sea areas that covers 45% of the earth, while South Pacific nations put an end to trawling in a large portion of sea. Still, bottom trawling is still very serious today with the fragile state are oceans system is in. With recent oil spills, the increased acidification of sea water and the ice caps melting our marine life is enough danger as is. We need to put an end to bottom trawling if we want to save our marine life. (Source on effects of bottom trawling)