Where vast schools of fish dwell, so too do the seabirds that prey on them. Able to dive swiftly from the air or even swim about beneath the waves, many seabirds seem as at home in water as they do in the air. Unfortunately for the birds’ sake, that tantalizing ball of fish may have been corralled together not by predators nipping from below, like in the clip above, but by a fisher’s nets. Every year, says a new study, at least 400,000 seabirds caught by fishers.
The main culprit, says the New York Times, seems to be gillnets—small to medium-sized nets that dangle with a float along the tip and weights at the bottom. Gillnets are a low-cost type of net, a technology that many small independent or local fishers rely on. Gillnets work by by catching the fish by their gills, but they’re also able to catch and drown seabirds. The study found that at least 81 different species of bird have been caught by gillnets, “including penguins, ducks and some critically endangered ones like the waved albatross.”
Bycatch, when other animals such as sharks or dolphins or turtles, or even unwanted species of fish are caught in the net, is a huge problem for fishers worldwide. The new research reminds us that the effects are not limited to the swimmers, and it’s not just a couple of birds here and there. The 400,000 number is a bare minimum, the researchers say, and the actual number is likely much higher.
More from Smithsonian.com: