WASHINGTON — On Sunday night, millions of viewers across the country will tune in to what has become an annual ritual of summer television, a combination of fear and morbid fascination: Discovery Channel's Shark Week.

Cable television's longest-running and most popular series celebrates its 25th anniversary this year, proving yet again that Americans have a seemingly insatiable appetite for stories about the ocean's top predator. But as Silver Spring, Md.-based Discovery seeks to keep its annual shark fest relevant, executive producer Brooke Runnette has begun to build an alliance with national conservationists who have spent years decrying the channel's programming as simplistic and short-sighted.

The campaign to transform Shark Week's image — entailing events ranging from a closed-door meeting at a Stanford University biology lab overlooking the Pacific Ocean to a screening and cocktail reception hosted by one of Washington's most influential ocean-advocacy organizations — is a work in progress. But it is already a case study in how two very different interest groups have decided they are better off together than apart: environmentalists who see the rehabilitation of sharks' image as critical to their continued survival and a cable company that needs something beyond the next "Air Jaws" shot.

In an interview, Runnette, a former news producer who took over the show in 2010, said part of her work is driven by a straightforward motivation to drive audience with fresh material: "What can I still do that's new, for god's sakes, after 25 years?"

After all, Discovery already ran "The 10 Deadliest Sharks," "Anatomy of a Shark Bite" and "Bull Shark: World's Deadliest Shark," more than a decade ago. So Runnette has sought to have viewers "see a shark differently," whether that's through advanced technology or an alternate story line.

In this year's version of Air Jaws, for example ("Air Jaws Apocalypse," in case you were wondering), filmmakers have constructed an underwater housing so they could take 1,000 frames of footage a second below the waves.

"You're suddenly so conscious of an individual who is looking back at you; that is so much more powerful than you," Runnette said. "When he looks at you and doesn't bite you, that's, in a way, more exciting."

And for activists — who include a group of shark-bite survivors working with the Pew Environment Group — the series provides an opportunity to reach the more than 30 million viewers who watch the shows each year.

"This is the ultimate melding of shark attacks becoming shark conservation," said Debbie Salamone, a Pew Environment Group communications officer who had her Achilles tendon severed while swimming off Florida's Cape Canaveral National Seashore in 2004. "I think it's really helping us."

Or as Mike Coots — who lost his right leg to a shark while surfing off the Hawaiian island Kauai — put it when describing being interviewed about his 1997 accident: "Most of the time, you're thinking, someone else is making a dime off of what I'm saying. With this, what I'm thinking is what I'm saying might inspire future stewards of the ocean."

This year, Discovery is offering two new segments with an explicit conservation focus. "Shark Fight" details the experiences of Salamone and five other shark-attack survivors and their crusade on sharks' behalf, while "Great White Highway" chronicles the work of Stanford marine biologist Barbara Block, who has used satellite and radio tagging to identify a critical migratory corridor for white sharks and other top marine predators in the Pacific Ocean. A third show, "How 'Jaws' Changed the World," looks at the ramifications of Peter Benchley's bestseller and the movie which it inspired, including how it contributed to the vilification of sharks.

Runnette noted that four of this year's shows make references to shark finning, the practice of cutting off a shark's fins so they can be used to make an Asian delicacy, shark fin soup. A new DNA analysis by Stony Brook University and the Field Museum in Chicago, with support from the Pew Environment Group, revealed that shark fin soup served in 14 U.S. cities contains at-risk species, including scalloped hammerhead. Scientists say the shark fin trade — which accounts for between 26 million and 73 million shark deaths per year — is one of the main reasons as many as a third of all shark species now face some threat of extinction, along with the accidental catch of sharks in long-lines set to catch species such as tuna and swordfish.

"I was thinking, maybe that's too much," Runnette quipped.

Several conservation groups and shark researchers, which had somewhat tentative relations with Discovery in the past, are now collaborating closely with it. Block, who helped pioneer the practice of tagging sharks, turtles, tunas and other marine species, initially rejected the script Discovery sent her because it overemphasized white shark strikes off the Farallon Islands.

But Block was pleased with the final result, which included a more than $1 million, two-year experiment funded by Discovery, the Monterey Bay Aquarium, the Census of Marine Life and Rolex that will use moveable gliders and radio transmitters to track the movements of more than 100 sharks in what Block calls "the blue Serengeti in our back yard" off California's coast.

"We know where the watering holes are, we know where the highways are and what we're trying to do is connect people to where these places are," Block said, adding that TV provides a critical megaphone for that work. "I've spent 25 years in conservation, mostly working on big fish, and I don't feel like we're winning the war completely."

Block is not alone: Both Oceana and the Pew Environment Group have worked with Discovery for three years; Nature Conservancy science specialist Kydd Pollock and his fiancee spoke on camera about how a gray reef shark became entangled in a net they set in the remote Palmyra Atoll two years ago and bit Pollock repeatedly on the head; and Shark Savers joined this year as a conservation partner.

Underpinning this shift is a simple calculation: Tens of millions of Americans get most of what they know about sharks from the series. At 29, Jason O'Bryhim — a George Mason University doctoral candidate in environment science and policy — has watched Shark Week for almost its entire run. (He's the sort of kid who produced a shark pop-up book in first grade.)

Between November 2007 and April 2008, O'Bryhim surveyed 200 people in Virginia about their views toward sharks; half of them had watched Shark Week, and that group was better informed. Studies have shown people who swim with sharks harbor fewer stereotypes about them; O'Bryhim speculated that watching Discovery amounts to the next best thing, since it "allows people to see sharks in their natural environment."

"With a higher level of information, they are more willing to support conservation," he said.

Pollock said that he viewed the segment as a chance to educate "the broader public" about the predicament these predators face. "Sharks are the creature at risk. It's not the humans," he said.

Some who have begun collaborating with Shark Week's producers, such as University of Sydney researcher Christopher Neff, said the series' heavy reliance on reenactments of shark strikes poses a problem. "Shark Fight," for example, includes six reenactments of such incidents, five of which are bloody.

"Vivid pictures often trump conservation messages in people's minds, so it is important to be aware that they can reinforce existing fears and stymie education," Neff wrote in an email.

Rebecca Regnery, deputy director of wildlife for Humane Society International, said the series represents "an opportunity that we should take advantage of, but they're not there yet," noting that she hasn't been able to watch a single episode in its entirety.

"I literally start yelling at the TV every time I watch it, and my husband makes me turn it off," she explained.

Mark Spalding, who heads the Ocean Foundation, said he wonders why Discovery can't make a radical departure when it comes to portraying sharks. "They're no less powerful, they're no less amazing, they're no less complicated if you tell their story without making them man eaters," he said.

But Runnette said she accepts the fact she'll always have critics who fail to grasp the commercial imperatives she faces.

"If sharks ever become boring, we're not going to be on the air."