Do you know where your sushi comes from? (Photo Courtesy of avlxyz/Creative Commons/Flickr)

George Leonard, director of aquaculture at Ocean Conservancy, a marine conservation group, has had a love affair with the undersea universe since he became a certified scuba diver at age 13. After hundreds of dives for self-fulfillment and academic research, Leonard, now a Ph.D. in ecology and marine biology, is a big fish in the field of sustainable seafood production, testifying on the subject before Congress and working tirelessly to protect our oceans.

Recently, Leonard has been hard at work as the National Oceanic and Atmospheric Administration (NOAA) develops a national policy on farming in the ocean. With healthcare reform, financial regulation and immigration legislation all on Congress’ plate during this session, why wade into aquaculture now? There are concerns that America’s hunger for seafood is draining fish from the seas and destroying the oceans’ once pristine waters, according to Casson Trenor, author of “Sustainable Sushi: A Guide to Saving the Oceans One Bite at a Time,” who also educates the public about the global seafood crisis for Greenpeace USA. Over-fishing is so rampant that some species of fish face extinction; the bluefin tuna, prized by sushi lovers, is considered critically endangered.

Yet as the world’s population increases and wild-caught seafood peters out, cultivating fish is the world’s fastest growing food production type. According to recent studies of aquaculture, fish farming accounts for 50 percent of global seafood consumption and is multiplying at the rate of 8 percent annually.

Fish farming is already a thriving industry in many American states, but the Obama administration is backing a bill to expand farming in federal waters. Currently, farmers must apply for a series of hard-to-obtain permits, which has curbed the industry’s growth.

While sustainable seafood is in demand by environmentally conscious consumers, just what constitutes “sustainable” remains unclear. When applied to seafood, it refers to the environmental health of farmed and wild seafood and of the oceans. Christophe Hille, co-owner of Northern Spy Food Co., a Manhattan-based restaurant specializing in sustainable food, notes that many of his customers know the ins and outs of sustainable meat production, but “there is something about the invisibility of the ocean that makes people turn their eye when it comes to understanding the meaning of sustainable seafood.”

The Monterey Bay Aquarium Seafood Watch says sardine populations from the Pacific Ocean appear to be "abundant and healthy" and are listed as a sustainable seafood "Best Choice." (Photo by Melissa Muller Daka/CNS)

Just as not all techniques for catching wild fish are healthy for the oceans, some seafood farming methods are more sustainable than others, says Trenor of Greenpeace. “To ask if a fish is farmed or wild is really not what we should be asking,” he said. “Multiple factors need to be taken into consideration when determining if a certain type of fish is okay to eat.” Salmon, for instance, “is better wild than farmed, assuming that wild salmon is coming from Alaskan fisheries,” but notes that he is “not talking about salmon that is harvested inefficiently.” Conversely, some fishing methods can harm the ocean floor and kill fish that the commercial fishermen aren’t seeking.

Fish farms also can bring other environmental complications to the table. For example, farm-raised fish eat food pellets, which contain a mixture of grain, hormones and antibiotics. Their concentrated fish excretions can contaminate the surrounding water and introduce harmful pathogens to wild fish. Pellets for carnivores, such as salmon and halibut also contain seafood, which contributes to the depletion of wild finfish.

By contrast, certain types of farmed seafood — mussels, clams and oysters, for instance — filter and purify the water they live in and feed on microorganisms in the water.

Ocean Conservancy's Model for Sustainable Aquaculture. (Courtesy of Ocean Conservancy)

According to Leonard, aquaculture is most sustainable when multiple species of sea life are farmed in unison, a technique known as “integrated multi-tropic aquaculture.” Each organism, from the seaweed to the clams to the lobster to the salmon works, in symphony with one another. The system works, claims Leonard because “it resembles a natural ocean habitat,” as opposed to a factory farm.

Aquaculture legislation offers a potential economic boon for Americans, such as job creation and lower priced seafood options, according to U.S. Rep. Lois Capps, D-Calif., who is spearheading the legislation. But before fish farmers venture into deep waters, they must also factor in environmental sustainability.

In December, Capps introduced the 2009 National Sustainable Offshore Aquaculture Act, which would streamline the permitting process for fish farming to move further into federal waters while also regulating the environmental sustainability of the oceans.

In a press release for her bill, Capps said that “developing these guidelines has the potential to preserve the integrity of our fragile ocean ecosystems, meet the increasing consumer demand for seafood, reduce stress on wild fish populations, and create jobs here at home.”

In the past five years, Congress twice introduced aquaculture legislation but failed to pass it, in part because of pressure from conservationists and fears about environmental hazards.

Capps’ proposed bill keeps NOAA responsible for regulating the industry and developing sustainable parameters so that farms in federal waters – from three to 200 miles offshore – can be established. But NOAA administrator Jane Lubchenco, a marine ecologist and environmental scientist herself, isn’t rushing into aquaculture farming. “I do not believe that we have identified the right conditions under which aquaculture is sustainable,” she testified before the Senate Committee on Commerce, Science and Transportation in a hearing earlier this month.

“The bill will empower NOAA to regulate aquaculture and is the logical place for aquaculture to be regulated,” said Leonard, of the Ocean Conservancy. Such NOAA’s listening sessions are currently under way in Rhode Island, California, Louisiana, Hawaii, Washington and Alaska. They have been attended by local fishermen, who are concerned about the risks associated with fish farms on wild fish.

While the Ocean Conservancy has tried to drum up interest in the public sphere, Leonard admits that specifics of sustainable aquaculture are “pretty esoteric.” NOAA is hoping that a national call-in event on May 6, will drum up more input, the better to develop a draft national policy. At the same time. Leonard is attending some of the “listening sessions” NOAA is holding, to be sure that “policy decisions are based on the best available science,” he said.

For his part, Trenor, of Greenpeace, says “we need to view all the fish in the sea as a network of different species and organisms that co-exist in conjunction with each other.” If such regulation is built into aquaculture legislation, he explains, fish farming could play a role in refortifying the oceans’ underwater kingdom.