June 28, 2017 — New research shows that industrial fisheries are responsible for dumping nearly 10 million tons of perfectly good fish back into the ocean each year—enough to fill 4,500 Olympic-sized swimming pools. This news comes at a time when nearly 90 percent of the world’s fish stocks are threatened by overfishing.
The research, published in the science journal Fish and Fisheries, shows that roughly 10 percent of the world’s annual catch is tossed back in the ocean. This waste happens for a number of reasons, including fishing practices that damage fish (making them unmarketable), throwing back fish that are too small or out of season, or because only part of the fish needs to be harvested (e.g. Alaska pollock roe). In some cases, fishers caught species they weren’t targeting (called bycatch), or they continue to catch fish even though they’ve caught enough, which they do in hopes of scooping up bigger fish (called high-grading).
“In the current era of increasing food insecurity and human nutritional health concerns, these findings are important,” noted Dirk Zeller, a researcher at the University of Western Australia, a senior research Partner with the Sea Around Us, and the lead author of the new study, in a statement. “The discarded fish could have been put to better use.”
For the study, the researchers examined the amount of fish that has been discarded over the past six decades. Estimates were made for all major fisheries around the world relying on, in the words of the authors, “a wide variety of data and information sources and on conservative assumptions to ensure comprehensive and complete time-series coverage.” Their analysis shows that five million tons of fish were discarded annually in the 1950s, a figure that skyrocketed to 18 tons annually by the late 1980s. This figure dropped to less than 10 million tons over the last decade.