Bottom Trawling

A Hexactinellid sponge reef destroyed by bottom trawling.

In British Columbia, groundfish such as lingcod, rockfish, sole and flounder are caught with the otter trawl, a large net that is dragged along the ocean floor. The otter trawl is long and wedge-shaped, narrowing into a bag called the cod-end. The mouth of the net is kept open during trawling with water pressure on two steel "otter doors”. Because the nets are weighed down and dragged along the ocean floor, any living thing in their path is damaged or completely destroyed.

Bottom trawling is practiced throughout the world's oceans and there is consensus among the international scientific community that it is the most destructive fishing practice taking place in the oceans today. Of greatest concern is its ability to destroy deep sea habitat such as corals and sponges.   

Every year, bottom trawlers on the high seas lay waste to a combined area of seabed twice the size of the U.S. for less than half of one percent of the world’s annual wild fish catch. Regardless, Canada refused to support a United Nations moratorium on bottom trawling.

The bottom trawl fishery in B.C. is 100% observed. Living Oceans Society obtained trawl observer data for the years 1996-2004 and has conducted a comprehensive analysis of the effects of bottom trawling in B.C. waters. Based on the results of our research, we are working hard to ensure that bottom trawling is stopped in areas of significant coral and sponge habitat, and that it does not expand into new, untrawled areas.

Bottom trawling is non-selective because it pulls everything in its path into the net. As a result, it is responsible for a great deal of waste, referred to as "bycatch" by fisheries managers.

Living Oceans is currently analyzing the trawl observer data  bycatch, and will make the results of our work available in the summer of 2008.