A recent study conducted by Australian and Canadian researchers in partnership with the Sea Around Us organization revealed that nearly 10% of the fish caught worldwide – in other words, 10 million tons – is wasted every year by being thrown back into the sea.
The research program, which was conducted over a five-year period and supervised by 300 worldwide experts, brings to light poor fishing practices and inappropriate management of resources.
The wasteful practices lead to a yearly loss of the equivalent of 4,500 Olympic-size swimming pools filled with fish. As lead author Dirk Zeller explained:
"In the current era of increasing food insecurity and human nutritional health concerns, these findings are important. The discarded fish could have been put to better use."
According to the report, fishermen get rid of a portion of what they catch for a variety of reasons. It may be because the nets have damaged the fish, making them unsellable, or because the fish are too small or not in season.
In the worst case scenario, the fish are wasted because they simply weren't the target species. According to the WWF, nearly 40% of the sea creatures caught were not the target species. In other words, nearly 38 million tons of sea animals are caught unintentionally. Dirk Zeller continues:
"Discards also happen because of a nasty practice known as high-grading where fishers continue fishing even after they’ve caught fish that they can sell.
If they catch bigger fish, they throw away the smaller ones; they usually can’t keep both loads because they run out of freezer space or go over their quota."
The study reports that in the 1950s, the fishing industry threw back nearly 5 million tons of fish each year, then up to 18 million tons in the 1980s, only then to fall back to 10 million per year in the last decade – which isn't necessarily a good sign, according to the researchers.
Rather than attributing the decline to better fishing practices, the researchers say it is likely due to reduced fish stocks in the oceans. One previous study reported that since the mid-1990s, the number of fish caught had fallen by 1.2 million tons per year. Zeller concludes:
"Discards are now declining because we have already fished these species down so much that fishing operations are catching less and less each year, and therefore there’s less for them to throw away."