The bears have returned to the river and are packing on the pounds as another Fat Bear Week begins at Katmai national park.

The 12th annual Fat Bear Week, in which the public will vote for the fattest of Katmai’s brown bears as mothers, cubs and males gather along the salmon-run at Brooks river in Alaska begins on Monday.

The single-elimination tournament celebrates the park’s brown bears as they build their fat reserves ahead of their winter hibernation, and serves as an opportunity for distant viewers to enjoy the remote national park. Last year, more than 1.7m votes were cast from 100 countries before the public crowned Bear 32, nicknamed “Chunk”, that year’s victor.

With this year’s bracket dropping on Friday, fat bear enthusiasts have the weekend to research the competitors before the tournament, which runs from 22 to 29 September, kicks off.

It’s gearing up to be one of the fattest weeks yet.

‘A bear might have a really compelling story from early summer, but if they don’t show up in September, then we can’t compare,’ park superintendent Mark Sturm says. Photograph: Explore.org

“There are more cubs at Brooks Camp this year than have been seen in a long time,” Mark Sturm, the park superintendent, said in a statement. “A new generation of fat bears is taking shape, and they’re off to a strong start.”

Fat Bear Week, which started in 2014, first began as Fat Bear Tuesday. At the time, the park posted a bracket on Facebook similar to the one now in use, showing side-by-side photographs of the park’s brown bears as they bulked up between June and September.

Mike Fitz, who was a National Park Service ranger at Katmai at the time, recalls: “The engagement on those few Facebook posts that we did was super high, like way higher than anything we had tried at the park previously.”

That gave him the idea to develop a way for more people to participate: hosting a week-long event that would take advantage of the livestream cameras the philanthropic group Explore.org had installed in the park in 2012.

“One of the things that makes the webcam experience really special is that we get to follow the stories of individual bears, so we know them across the season and years,” said Fitz, who is now the resident naturalist at Explore.org. “And that helps us to form deeper connections with them and tell their stories about surviving in the wild.”

Fat Bear Week is also part of a larger strategy to bring people inside a national park they otherwise might never travel to. Located 260 miles (420km) south-west of Anchorage, Katmai is one of the nation’s most remote national parks.

But it’s in part that remoteness that makes Katmai so special – it is home to the world’s last great salmon run and approximately 2,200 brown bears.

“Every year, tens of millions of salmon return to this region,” said Fitz, who adds that rangers have seen hundreds of thousands of salmon moving along Brooks river, where Katmai’s brown bears congregate. “Without salmon, there would be no Fat Bear Week. They’re amazing creatures in their own right, and they are the keystone of the ecosystem.”

Fitz credits last year’s large salmon run with this year’s especially large number of brown bear cubs. “If you are a well-fed brown bear you are more likely to have cubs in the den and you’re also more likely to have a large litter,” he said.

As a result, Fitz says there will be more families represented in Fat Bear Week this year than ever before. He hopes that helps viewers continue connecting with Katmai’s brown bears.

“We see a lot of ourselves in brown bears. We see how hard mother bears work to raise their cubs. We understand their hunger, at least on some level,” he said. “Each bear tells us stories about survival in the wild.”

Sometimes those stories can be painful – like last year, when 32 Chunk broke his jaw, or the year before, when a male bear killed the young cub of reigning fat bear champion 128 Grazer – but Fitz says it’s important to Katmai and Explore.org “to be transparent about the lives of these bears”.

“It is filled with a lot of joy and fun – we see the bears playing with one another. But they face real risk. They face real hardship. They’re fierce, large predators,” he said.

Like viewers online, Fitz and the rangers at Katmai have bears they have connected with and are eager to follow over the week.

More than a decade after it started, Fat Bear Week ‘has become a phenomenon’, Strum says. Photograph: Explore.org

“There’s a bear, No 910, who didn’t have cubs this year – she had cubs in the past, but she was single this year – she’s just a balloon,” he said. And Bear 164, nicknamed Bucky, is “showing an increasing dominance of the river over the last several years”, he added. “He’s not even 10 years old and he’s just a giant.”

During a livestream event leading up to Fat Bear Week, Sturm, the park’s superintendent, said he hoped 32 Chunk, who’d been slow to make an appearance at Brooks river, would make a comeback.

“A bear might have a really compelling story from early summer, but if they don’t show up in September, then we can’t compare,” said Fitz, who explained not all bears can make it onto the bracket, even if they’re fan favorites.

At the very least, Fitz said: “I hope it gives people an opportunity to break away from the madness of the world and the rest of the internet.”

For more than a decade Fat Bear Week “has become a phenomenon”, Strum said during a 9 September live stream, which “certainly helps us deliver our message about the importance of large landscape conservation, brown bear conservation, and just having functional ecosystems that are healthy and viable”.