Bottom Trawling

"Bottom Trawling is the subsea equivalent of collecting the entire farm, when the goal is to bring in a bushel of apples." - Dr. Sylvia Earle

Bottom trawlers drag weighted nets along the sea floor, scraping it bare as they scoop up everything in their path. Corals, as well as any unintended species of fish, are called “bycatch” that  trawlers throw overboard, dead or dying.

Trawled seafloor in Mid-Moresby Gulley. The sub pilot who filmed this scene said that the seafloor looked as if it had been ploughed.

Early scientific research expeditions to find coral were often inspired by fisheries collapse, and the fear that corals were being wiped out by fishing methods that contact the bottom. Norwegians discovered that over half of their lophelia coral reefs had been destroyed by bottom trawling, and Florida's oculina coral reefs were reduced to rubble by bottom trawling and had to be closed to all fishing activity.

Today, we know that many species of corals not only provide essential habitat but are slow-growing, long-lived, fragile, and vulnerable to human impacts.

Living Oceans Society obtained observer data from B.C.’s bottom trawling fleet covering the years 1996-2002. We analyzed the data and found that during those years, bottom trawlers threw away 2,300 tonnes of bycatch, enough dead sea life to fill a line of pickup trucks parked bumper to bumper from Vancouver to Prince George. Of that bycatch, 295 tonnes were corals and sponges.

In 2002 the B.C. bottom trawl fleet landed 98,000 tonnes of fish, making it the largest fishery in the province by volume. Its catch, however, received the lowest average price per pound of any B.C. fishery. Much of the catch ends up as fish sticks.