Who's the fattest salmon-feaster? Fat Bear Week in Alaska a 'really close call'

The fiercest, fattest contestin Alaska is raging onlinethis week and the competitors are true heavyweights.

Fat Bear Week is delighting the internet, as the public votes for their favourite salmon-slammer.

"Its a contest the contestants are completely unaware of," said Sara Wolman, project manager with Katmai Conservancy. The annual bracket contest has been celebratingbrown bears in Brooks River in Katmai National Park since 2014.

Each day the public votes for the fattest bear, as they chunk up on salmon before winter hibernation.

Twelve bears compete, and one will be crowned champion on Tuesday. The bracket-style tournament pins two bears against each other in daily elimination rounds.

People can also watch the bears feast in the river via a live bear cam.

Wolman is pulling for Bear 747, a "really big" bear who weighed 1,408 pounds last year.

Last year's winner, Holly, was crowned the Queen of Corpulence.While she's back in the running this year,Wolman said she nowhas cubs to feed so is not quite so bulky.

Wolman says"Otis" Bear 480 is a long-time fan favourite.

"He's one of the oldest bears," she said. He sits at the far end of the falls and waits for salmon to come to him.

"They call him Zen Master Otis because he's just very chill."

There's also "Chunk," formally known as Bear 32.

The bears are in a state of hyperphagia, a drive to keepeating in order to store fat before winter.

"It essentially allows them to keep eating and eating and eating," she said.

"These guys are doing really well this year. We had a pretty robust salmon run this year so these guys have packed on the weight. It's going to be a pretty close call."

Bristol Bay is home to the world largest salmon fishery, and the bears are "just feasting on them."

She's not sure neighbouring Yukon bears can compete.

"The reason why they get so fat is because they have this massive salmon run," she said.

"Some of these bears are probablythe biggest ones, if I dare say, in the world."

Wolman says the contesthas become a good way to educate the public on "how amazing these bears are."