It’s long been believed that the decline in the number of Stellar sea lions off the coast of Alaska was due to over-fishing – the sea lions being out-competed by humans in fishing vessels. So certain areas of ground fishing were put off limits to humans so the Stellars would get more to eat.
Still, the Stellars have not recovered.
But perhaps the riddle has been solved by a researcher at Hatfield Marine Science Center’s Marine Mammal Institute. Researcher Markus Horning is developing evidence that strongly suggests that by fishermen being force out of those ground fish fishing areas, fewer Sleeper Sharks have been part of any by-catch thereby leaving more of them in the water to prey on juvenile Stellars. Could it be that by re-opening more ground fish fishing to commercial fishermen, and snagging more Sleeper Sharks in the bycatch, predation of Stellar sea lion juveniles might be reduced, thereby producing more adult Stellars?
It may sound counter-intuitive but maybe not after you read the details of Horning’s research. Click here.