Assignment Earth: Entangled sea lions
Off Alaska's coast, new research shows how entangling fishing gear and trash cause devastating consequences for Steller sea lions. (Video: Assignment Earth)
>> Some stellar sea lions like to dine on what you might call fast food. They follow fishing vessels, trying to steal the catch.
>> If there’s a fish on a line, it’s probably a lot easier for them to go take that fish off the line than to expend a lot of energy to go find their own food. So, they’re not much different than us in that way.
>> But the consequences can be devastating. Along with fish, sea lions also swallow the hook. The sharp metal can puncture the esophagus or stomach, leading to massive infection and death. Fishing lures attached to lines also get caught on their lips. These marauding marine mammals also cause economic hardship for Alaska’s fishing industry, which feeds American consumers. They not only steal the catch, but also damage gear and force crews to move to new waters. Researchers first noticed the extent of the problem in 2000, while surveying sea lions along the coast of southeast Alaska and northern British Columbia. Working under a Federal permit, biologists have documented nearly 400 entangled individuals as part of an ongoing survey for Alaska’s Department of Fish and Game. Swallowed hooks are only part of the problem. Sea lions also get entangled in fishing debris such as nets, packing bands and rubber crab pot bands. Curious by nature, sea lions may even seek out and play with the debris. Once a band gets caught around its neck, a sea lion has no way to remove it. As a young animal grows, a band can cut into its blubber and muscle tissue, causing infection and slowly strangling it.
>> It’s very distressing to see these animals when we really want to work toward ways to reduce the amount of marine debris out in the ocean and find ways of disentangling these animals.
>> Prevention is key. Securing fishing gear on boats could keep it from washing overboard in rough seas. Researchers also hope to work with the fishing industry to look for innovations in gear and methods that could benefit fishing fleets and sea lions. Also, properly disposing of fishing nets and cutting loops on plastic and rubber bands before throwing them away could keep marine species from becoming entangled. Cleaning up beaches and preventing plastics from blowing out of coastal landfills also could keep deadly debris out of the ocean, making it safer for sea lions.
>>For Assignment Earth, I’m Gary Strieker.