Alaska Department of Fish and Game has released a heartbreaking video that shows the deadly effects of fishing gear and marine debris on seals and endangered sea lions.

The horrifying images show sea lions being strangled by plastic bands caught around their necks and seals with large fishing hooks protruding from their heads. In one image, a drowned sea lion is shown trapped in a wind sock.

In a recently released study, Alaska's Steller Sea Lion program spotted 386 animals that picked up some type of debris between 2000 and 2007.

"We are certainly underestimating the number of animals entangled," Steller Sea Lion program biologist Lauri Jemison told Live Science.

Researchers hope the video will raise awareness about the seriousness of marine pollution.

Warning the following video contains graphic images.

Watch this video from Live Science, uploaded Feb. 14, 2012.

(H/T: Daily Mail)