With the world’s wild fish stocks plummeting, experts say that something must be done to ensure our seafood supply. Are offshore fish farms the solution?

“Are you ready to see the future?” Vinny Allocca calls out gleefully, his voice rising from the sun-dappled surface of the Hawaiian sea. Allocca has timed his question perfectly. He’s caught me midstride off the deck of the Ho’Okupu, a 32-foot commercial workhorse that belongs to his employer, Randy Cates, a fisherman turned “fish farmer.” My only possible answer to Allocca’s question is the affirmative ker-plunk of my scuba fins hitting the water.

The “future” to which Allocca refers is not just 40 feet down, although that’s what my depth gauge reads when we stop descending. It is also nearly two miles from shore. The combination of these two positions, depth and distance from land, makes open-ocean aquaculture (OOA) the topic du jour in the seafood industry—and a hot-button issue for many outside the trade. Most existing fish farms use shallow-water pens that hug the coastline. The arrangement has a mixed record. Workers can feed and harvest fish efficiently from docks, but poorly managed fish wastes can easily foul near-shore waters, causing “dead zones” where ocean life dies off, and leading to disease in wild fish and other species. But now, new and still-emerging technologies have aquaculture poised to take a giant stride out to sea, where proponents say that massive ocean currents will sweep away any pollution problems.

Last June, the Bush administration gave OOA a tremendous boost, sending Congress a bill that would for the first time allow aquaculture in federal waters—stretching from three miles to 200 miles off the mainland, an immense area larger than the combined landmass of the lower 48 states. The bill’s stated (though vague) goal of streamlining the permitting process for OOA has supporters cheering—and critics foreseeing an under-regulated offshore industry that repeats the mistakes of near-shore fish farms. But with consumer demand for seafood increasing and wild stocks dwindling, the government’s point man on the issue, Michael Rubino of the National Oceanic and Atmospheric Administration (NOAA), says that aquaculture is reaching a tipping point in this country. “Any increases in [seafood] supply,” he says, “are going to come from aquaculture.”

  Courtesy Kona Blue
A half-raised SeaStation 3000 operated off the Big Island of Hawaii by the company Kona Blue

The water is still clouded by sand kicked up by an early morning squall, and so it’s not until we’re almost on top of it that I spot the Sea-Station 3000, an enormous fish cage that is impressive both for its grand scale and its elegant design. Manufactured by Seattle-based Net Systems, the SeaStation certainly looks futuristic. Or retro-futuristic may be a better description, since the cage most resembles a flying saucer from a 1950s sci-fi flick.

A horizontal steel rim 82 feet in diameter encircles a vertical central spar the height of a four-story building. The netting, stretched between the spar ends and the rim, has a weave less than an inch in diameter and is made of Dyneema fibers—an ultrahigh-molecular-weight polyethylene that is 10 times as strong as steel and yet floats and can be cut with a knife.

The SeaStation 3000 has an interior volume of 3,000 cubic meters (hence its name), which translates into 792,516 gallons, or more water than in most of the palatial hotel swimming pools along Waikiki Beach. The cages, which each weigh 10 tons and cost around $110,000, can be submerged in just 15 minutes by flooding the hollow spar with ocean water. At 40 feet down, they pose no hazards to passing ships and are themselves protected from large ocean waves. According to Net Systems’s aquaculture manager Langley Gace, the metal framework should last 20 years in the water; he puts the net’s life span at a decade.

Cates International has four of these structures tethered to the seafloor off Oahu’s southern coast, 120 feet beneath the surface, and plans to add several more over the next year or two. Allocca unzips an opening in the net barely big enough for a single diver, and we haul ourselves into one of them.

At first, I feel a bit like Alice must have after stepping through the looking glass, but instead of white rabbits and mad hatters, this marine wonderland is filled with 100,000 silvery fish that swirl around the central spar. They are adolescent moi, also known as Pacific threadfin or Polydactylus sexfilis. For the first 50 days of life, the moi are raised on land, in a series of progressively larger tanks—from fertilized eggs smaller than grains of salt to two-inch fingerlings. The young fish are taken by boat to the submerged cage and pumped into it through a long tube. The moi swarming around the spar now each weigh half a pound. But in a few months they’ll have doubled or tripled in size. At that point, the moi will be harvested and sold at fish markets and to top restaurants across Hawaii, where they are a much-coveted delicacy. Ancient Hawaiians considered moi so delicious that only the alli’i, or royalty, were allowed to eat them. Apparently, it’s not just humans who like the taste of moi. Several sandbar sharks circle the cage, their hungry eyes fastened on the fish of kings.

If this mammoth cage full of fish is a bright vision of the future, as Allocca insists, it is also a reflection of a darker past. Once plentiful, moi have been fished nearly to extinction. As recently as 1967, commercial fishing operations landed 10 tons of the royal fish. By the new millennium, that figure had plummeted to just 740 pounds—about as much seafood as popular restaurants here serve on a busy Saturday night.

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