They also provide a habitat for fish and other species of ecological and commercial interest, such as orange roughy, swordfish, tuna, sharks, turtles and whales.
Bottom-trawling's knock-on impacts are best illustrated by the plight of the deep-sea fish, the orange roughy (also known as slimeheads) whose populations have been reduced by more than 90%, according to marine scientists.
Last year, the company stopped selling seven other species on the Greenpeace red list including Atlantic cod, Chilean sea bass and orange roughy, says Jeff Lyons, Costco's senior vice president of fresh foods.