Sweden's grey seal was once terribly endangered, its population thinned almost to nothing in the 1970s from pollution and hunting in the Baltic Sea. But then the seal population began to bounce back in the 1980s. And today, in the coastal waters off Sweden, there is a pitched battle going on between the restored ranks of grey seals and the Swedish fishing industry. A new study reveals that the seals are eating as many fish as the fishing industry brings in each year, and that they're doing it in part by stealing from fishing boats and traps.
Marine biologist Karl Lundström, a researcher with Sweden's University of Gothenburg, recently published the results of a long-term study of the grey seals' diet. Like their human counterparts in Sweden, the seals are mostly eating herring, but they're also chomping on salmon and pretty much every other fish they can. They are, as Lundström put it, "fish-eating predators at the top of the marine ecosystem." And by "top," he means above humans. Though the Swedes have built fishing nets that are supposed to be humane and seal-proof, the seals turn out to be fairly ingenious at figuring out new ways to steal fish from them. As you can see in these videos, taken over the past several years, the seals do everything from jumping inside the nets and back out, to just ripping the crap out of them.
Some seals have learned to hunt at the push-up trap that has been developed for the small-scale fishing of salmon and whitefish in the Baltic. The trap has a seal-safe chamber in which the caught fish are collected, supposedly safe from the seals. Despite this, damage caused by seals has not been fully eliminated. Some seals, quite simply, have managed to figure out the equipment, and overcome it. By filming seals who hunt close to the trap, the scientists could identify ten individuals who had become specialists in hunting in the trap. These seals returned to the site over a long period.
[University of Gothenburg marine ecologist Sara Königson says] "Since we now know that it is only certain seals who are responsible for the damage, we have the chance of limiting the damage in a certain region, simply by removing these individuals."
So it's humans vs. seals, and the seals are currently winning — unless the scientists and fishing industry get their way and "remove" the smartest of the seals.
For people who fear the extinction of cute seals, this is weirdly heartwarming tale of how these fierce but cute predators fight back with strength and smarts. It's also a reminder that when humans don't play dirty by murdering other animals with guns, we're not the only apex predator in the ecosystem.
Read more via University of Gothenburg