“With 80,000 fish in eight pens, John Steiner’s Atlantic salmon farm in Rich Passage is small for an aquaculture operation.That doesn’t make running it any less work.One of the common things with all of the farmers out here is that you get to go through some of the worst days in your life, said Steiner, and that’s when it’s 30 degrees outside, waves are pouring over the fish pens, and you’re just really getting pounded by the howling wind.But on a calm summer morning, all of that seems hard to imagine as Steiner arcs out smoothly from the dock in his motorboat and casually moors against pens full of salmon jumping in such constant frenzy that one wonders if they don’t envy the pleasant weather above.Looking down at the underwater mesh cages bowed outward by the strong, cleansing tide of Rich Passage, Steiner observes: If you know that water is 700 times denser than air, anything going on down there is like a storm. Such volatility, however, is exactly what makes Steiner’s location – and that of his neighbor, the much larger Northwest Sea Farms – such prime real estate for raising salmon. Strong currents coursing through the pens give the fish crucial exercise, producing lean, healthy fillets.A lot of people say we should call it fish ranching, Steiner said, because these salmon are ‘free ranging.’The label also seems apt because keeping each batch of 7,500 fish safe inside 75,000-cubic-foot pens evokes the type of coyote-cowboy tension not seen since the Wild West.Packs of sea lions often attack the caged fish and suck out their guts through the pens’ nylon mesh. And dogfish will gnaw at dead salmon collected at the bottom of the nets and eventually break through.To prevent such attacks, divers were at work last week installing a predator net around the pens’ perimeter, designed to fend off hungry jaws with a thick plastic mesh.Diver Paul Weber, who quit installing the net when the tide grew too strong, said, It was really interesting when it got to the ebb. It was like somebody pushing a truck against you.Such currents have in the past been enough to break aging net pens, as it did last year at the adjacent Northwest Sea Farms, releasing 100,000 Atlantic salmon.Another threat to aquaculture comes from toxic algae blooms carried in water currents. These red tides can sweep in and decimate fish populations in a matter of hours.A scientist who studies such algae blooms and how to fight them, Laurie Connell from the Northwest Fisheries Science Center pulled up to Steiner’s fish farm in a boat last week to warn of a potential algae threat. In return, Steiner gave her several fish to serve as measuring sticks against others that could later be exposed to the algae.Connell said such resources serve an important function.We need the fish farms, she said. Otherwise we can’t do our research.Past red tides have created problems for the Rich Passage farms. In 1997, Northwest Sea Farms tried to avoid an algae bloom by towing a fish pen to safety near Vashon Island, but snagged a portion of netting on rocks, releasing more than 350,000 Atlantic salmon.Before purchasing his own fish pen from Northwest last year and refurbishing it, Steiner worked as the company’s senior diver for 15 years, repairing nets, anchoring pens and cleaning the submerged structures. Having spent thousands of hours underwater, he has noticed native fish stocks dwindle significantly since the 1980s.It’s like night and day, he said. There used to be tons of rockfish, and especially perch. There used to just be millions of them. But due to everything from overfishing to construction of bulkheads, the sight of dense schools of fish has become increasing rare and now elicits strong reactions in many who paddle by Steiner’s salmon pens.I think some of it is that people feel sentimental almost because there are so few fish in the sound, he said, and they float by and see all these fish jumping and it kind of gives people a great feeling.Steiner’s first crop of fish, a steelhead/trout mix, should be available by this fall, followed by the salmon in February or March.We’ll start a whole thing of making the fish available locally, he said. Probably what we’ll do is focus more just on Bainbridge Island.”