Commercial fish farming thrives in Rich Passage, earning critics, ardent fans.

Set at the top of a thrashing, silvery heap, the three-footer with blazing-pink gills is one of the first to go.

Plucked at its prime, the Atlantic salmon and a half dozen others are, in one gulp, sucked upward through a vast vacuum tube and sent zipping down a water slide awash with fish blood and saltwater.

“Okay, here they come,” says one salmon harvester, coated from head to foot in orange rubber.

He stands astride a roaring machine, watching for wily fish that dodge or clog a gauntlet of automated catchers.

“The first wave is a stunner, where the fish are stopped briefly and knocked in the head,” he said as hammers thud near his feet. “Then they get spun upside down and get bled with a knife (that) comes in and cuts their gills.”

It’s harvest time at the island’s largest farm, where 10 million pounds of salmon are raised in vast net pens covering two acres in Rich Passage, just south of Fort Ward State Park.

“It’s a quick process,” said Rob Miller, who manages the nearly 40-year-old farm for Anacortes-based American Gold Seafood. “The fish go from swimming here to the plate within a day.”

While fish farming has plenty of detractors who cite a range of ecological impacts, American Gold likely has even more customers. That base is growing into new territory, as the company makes allies of old enemies, one serving at a time.

With no added steroids, antibiotics or hormones, American Gold’s salmon are now featured in over 40 Whole Foods grocery stores.

The chain, which bills itself as the world’s largest retailer of natural and organic foods, established an account with American Gold last year after the farm put 20 percent of its Bainbridge stock on a more “natural” diet.

“We’re the only natural salmon farm in the U.S.,” Miller said. “We want to be a frontrunner in this developing market.”

The feed is made from a mixture of herring, anchovy, soybeans, corn and wheat. It also contains a natural dying agent that turns gray fish flesh pink, the color of wild salmon preferred by consumers.

At one of the farm’s 20 pens, Miller starts up a feeding machine that fires brown pellets through a pivoting barrel. The salmon race into action, gobbling feed near the water’s surface.

Miller observes their actions through an underwater camera to ensure that the fish are not allowing the feed to drift past the nets.

“Not much gets by them,” he said. “They like the stuff pretty well.”

But not everyone is taking the bait.

“We don’t carry farm-raised salmon because of concerns about how the salmon are raised and the damage to the environment,” said Karen Nakata, manager of Town & Country Market’s seafood department.

The Bainbridge-based chain, which includes six stores, stopped carrying farm-raised salmon in 2002. Nakata has a long list of reasons why.

“The excrement they produce, the pesticides, the pollution that smothers the underlying ground, the escapes, the threats to wild salmon…,” she said. “There’s a lot of reasons, (so) we try to be careful about what we’re doing.”

Anne Mosness, an aquaculture specialist with the Institute for Agriculture and Trade Policy, said the state’s active farms released nearly 5 million pounds of waste into Puget Sound in 2005.

“It’s like having hog farms in our state and federal parks,” she said. “These are feed lots that are out of sight, but I don’t believe we’d tolerate this if we had comparable waste coming from industries on land. This industry is expected to grow, yet it’s not taking care of it’s own sewage.”

Dan Swecker, secretary-treasurer of the Washington Fish Growers Association, said the industry has made strides in reducing fish pen density and better monitoring to alleviate waste problems.

“It’s not creating mass pollution,” said Swecker, who is also a state senator representing parts of Thurston and Lewis counties. “This waste is largely in a liquid form and dissolves immediately. The material that sinks to the ground biodegrades. It’s totally organic.”

Miller said the Bainbridge fish farm is well-suited for dissipating fish waste.

“We have very strong tides,” he said. “It flushes well and keeps the water clean.”

American Gold, a subsidiary of Smoki Foods Inc., owns all four of the state’s saltwater salmon farms. The Bainbridge facility, which employs 15 people, was purchased from a Norwegian seafood company in 2005, about 15 years after the pens were cleared of chinook salmon and and refilled with Atlantics.

“They just live in captivity easier and don’t get too excited,” said Devon Blankenship, who has worked at the farm since 1974. “Atlantic salmon are more docile. The difference between raising chinook and (Atlantics) is like trying to farm deer versus cattle.”

But keeping pens of captive marine carnivores doesn’t sit well with wild fisherman Paul Svornich.

“They have no business farming these fish in containers,” the island native said, contrasting the life of a salmon crowded in pens to a wild salmon’s “natural cycle” from birth in “pristine spawning grounds high in the mountains…to the vast open streches of the Pacific Ocean and then back into the mountains again.”

Raising Atlantic salmon in Puget Sound, rather than native species, has also raised concerns among environmentalists.

According to Mosness, escaped Atlantics could potentially begin breeding in Washington rivers and compete with threatened native salmon.

“They’re very plastic, very adaptable,” she said. “They eat the eggs and juveniles of Pacific salmon. It would be catastrophic if Atlantic salmon colonized our rivers.”

A United States Department of Agriculture study also warns of Atlantic salmon’s potential dangers.

“(L)ong-term risks may be substantial if fish continue to escape from marine rearing pens or freshwater hatcheries,” wrote the study’s author Peter Bisson last year. “The two greatest threats appear to be that Atlantic salmon could transmit a serious disease or parasite to native fishes, and escaped salmon could eventually adapt to local conditions, leading to self-sustaining populations. If Atlantic salmon populations are eventually established, this species’ preference for swiftly flowing stream habitats could facilitate competition with currently at-risk species such as steelhead.”

Hundreds of thousands of farm-raised Atlantics have escaped into Puget Sound waters over the years, including 350,000 from the Bainbridge facility in 1997 and 100,000 at another nearby farm two years later. Yet, the species has not yet reproduced in the wild.

“We’ve seen no evidence that that’s occurring,” said John Kerwin, who oversees fish farm permitting for the state Department of Fish and Wildlife. “We’ve seen Atlantic salmon in the Green and Cedar rivers for many, many years. But they’re not becoming established, they’re not interbreeding and not reproducing.”

Parasites outbreaks, also a recent concern in British Columbian waters, has been largely overblown, especially as it relates to escaped Atlantics, according to Kerwin.

“I’ve read a lot about the B.C. sea lice after it hit the press,” he said. “But these lice occur naturally and we are not seeing high concentrations or an epidemic in Washington state.”

Miller said American Gold has added double netting around pens to avoid escapes, which were often caused by hungry marine mammals.

Last year, no salmon escaped from the Bainbridge facility, although about 1,000 were eaten by predators. Statewide, Kerwin reports no significant salmon escapes over the last year.

Despite recent steps taken to improve the industry, other states including Alaska and Oregon do not allow commercial salmon farming in pens.

While noting the industries’ shortcomings, Bainbridge Island Chamber of Commerce Director Kevin Dwyer said the Bainbridge facility has long been a key part of a diverse island economy.

“They’ve been here for decades” he said. “This island has had shipbuilders, timber mills and people making nets for the fishing industry. This company has a historic link to the water and it reflects our marine heritage.”

According to Blankenship, who has seen over 30 years of changes at Bainbridge facility, the best is yet to come for island fish farming.

“What we’re doing is new and on the cutting edge,” he said. “Mistakes have been made in the past, for sure. But we’re doing what we can – and it keeps getting better all the time.”