Skip to main content

The Globe and Mail

Ten per cent of fish caught in oceans get thrown back, study finds

Industrial fleets often throw back fish that are damaged, diseased, too small or of an unwanted species.

Courtesy Pacific Wild

Fishing fleets dump about 10 per cent of the fish they catch back into the ocean in an "enormous waste" of low-value fish despite some progress in limiting discards in recent years, scientists said on Monday.

A decade-long study, the first global review since 2005 and based on work by 300 experts, said the rate of discards was still high despite a decline from a peak in the late 1980s. Discarded fish are usually dead or dying.

Almost 10 million tonnes of about 100 million tonnes of fish caught annually in the past decade were thrown back into the sea, according to the Sea Around Us review by the University of British Columbia and the University of Western Australia.

Story continues below advertisement

Industrial fleets often throw back fish that are damaged, diseased, too small or of an unwanted species. A trawler with a quota only to catch North Atlantic cod, for instance, may throw back hake caught in the same net.

Discards are an "enormous waste … especially at a time when wild capture fisheries are under global strain amidst growing demands for food security and human nutritional health," they wrote in the journal Fish and Fisheries. The report welcomed the decline in discards from a peak of about 19 million tonnes in 1989, roughly 15 per cent of a total catch of 130 million tonnes.

The fall may be linked to restrictions in some countries on discards and improved fishing gear. Also, a rise in the price of fishmeal for aquaculture made it profitable to keep formerly low-value species, it said. But it might just reflect a lack of fish.

"We suspect that [the decline] is because overfishing … has already depleted the species being discarded," lead author Dirk Zeller of the University of Western Australia told Reuters.

Few fish survive getting thrown back, although some species such as sharks, rays or crustaceans are more resilient.

The scientists said discards were now highest in the Pacific, a shift from the Atlantic.

Report an error

The Globe invites you to share your views. Please stay on topic and be respectful to everyone. For more information on our commenting policies and how our community-based moderation works, please read our Community Guidelines and our Terms and Conditions.

We’ve made some technical updates to our commenting software. If you are experiencing any issues posting comments, simply log out and log back in.

Discussion loading… ✨

Combined Shape Created with Sketch.

Combined Shape Created with Sketch.

Thank you!

You are now subscribed to the newsletter at

You can unsubscribe from this newsletter or Globe promotions at any time by clicking the link at the bottom of the newsletter, or by emailing us at