In an Op-Ed featured on Huffington Post, aquaculture specialist and FSE director, Rosamond Naylor, supports a newly proposed House bill, the National Sustainable Offshore Aquaculture Act. The bill addresses the potential threats of poorly regulated, intensive fish farming in U.S. ocean waters, and ensures that U.S. aquaculture adopts a science-based, precautionary approach to protect our ocean ecosystems, fishing communities and seafood consumers.

With all eyes on the climate deliberations in Copenhagen, it is more important than ever to find innovative ways of reducing agriculture's contribution to global climate change. The livestock industry in particular has helped feed the world but at a significant cost to the environment, including generating large emissions of greenhouse gas.

One promising solution is to substitute fish production for meat production. But to do so we must ensure that the "blue revolution" in ocean fish farming does not lead to the same suite of environmental problems that have accompanied the "green revolution" for land-based agriculture. Americans' appetite for fish continues to grow and is increasingly met by a year-round supply of fresh fish imported into our marketplace. Yet few Americans know where their fish comes from or how it was produced. Just as most chickens, pigs and cows are raised in tightly confined, intensive operations, so too are many fish.

Right now in the United States we have an opportunity to help ensure that the emerging marine aquaculture sector meets both human and environmental needs. This week, Rep. Lois Capps (D-Calif.) will introduce in the House of Representatives a bill called the National Sustainable Offshore Aquaculture Act that addresses the potential threats of poorly regulated fish farming in U.S. ocean waters. These threats include spread of disease and parasites from farmed to wild fish; discharge of effluents into surrounding waters; misuse of antibiotics and other pharmaceuticals and chemicals; escape of farmed fish into wild fish habitat; killing of marine mammals and sharks that might prey on ocean farm cages; and reliance on use of wild-caught fish in aquaculture feeds, which could deplete food supplies for other marine life and the aquaculture industry itself over time.

These environmental impacts have been evident in many other countries with intensive marine fish farming. The recent collapse of salmon aquaculture in Chile, where industry expansion was prioritized over environmental protection, is the most glaring example. Salmon, one of Chile's leading exports, has suffered a major blow as a result of poor regulation and environmentally unsound management. Tens of thousands of people are now jobless in southern Chile, where the salmon farming industry once boomed.

There are three critical points to be made about the Capps bill. First, unlike previous attempts to legislate on fish farming at the national level, the bill would ensure that U.S. aquaculture adopts a science-based, precautionary approach that establishes a priority for the protection of wild fish and functional ecosystems. This approach is consistent with President Obama's recent call to develop a comprehensive and integrated plan to manage our ocean's many competing uses to ensure protection of vital ecosystem services in years to come.

Second, the Capps bill would preempt the emergence of ecologically risky, piecemeal regulation of ocean fish farming in different regions of the U.S. Efforts are already afoot in Hawaii, California, the Gulf of Mexico and New England to expand marine aquaculture without consistent standards to govern their environmental or social performance. If these piecemeal regional initiatives move forward, there will be little hope of creating a sustainable national policy for U.S. open-ocean aquaculture.

Finally, the Capps bill as currently written has a solid, long-term vision for the appropriate role of fish farming in sustainable ocean ecosystems and thus should win widespread support among environmental and fishing constituencies. It should also garner support from the more progressive end of the aquaculture industry that aspires to sustainable domestic fish production.

Previous federal bills introduced in 2005 and 2007 were fundamentally flawed -- and thus rightly criticized -- because they put the goal of aquaculture expansion far above that of environmental protection. Now, for the first time, a bill has been introduced that would demonstrably protect our ocean ecosystems, fishing communities and seafood consumers from the risks of poorly regulated open-ocean aquaculture.

Rep. Capps and her colleagues are to be commended. Now is the time for the new leadership in Washington -- at the White House and at the National Oceanic and Atmospheric Administration -- to embrace this more science-based and precautionary approach to ensure a sustainable future for U.S. ocean aquaculture.

Aquaculture, once a fledgling industry, now accounts for 50 percent of the fish consumed globally, according to a new report by an international team of researchers. And while the industry is more efficient than ever, it is also putting a significant strain on marine resources by consuming large amounts of feed made from wild fish harvested from the sea, the authors conclude. Their findings are published in the Sept. 7 online edition of the Proceedings of the National Academy of Sciences (PNAS).

"Aquaculture is set to reach a landmark in 2009, supplying half of the total fish and shellfish for human consumption," the authors wrote. Between 1995 and 2007, global production of farmed fish nearly tripled in volume, in part because of rising consumer demand for long-chain omega-3 fatty acids. Oily fish, such as salmon, are a major source of these omega-3s, which are effective in reducing the risk of cardiovascular disease, according to the National Institutes of Health.

"The huge expansion is being driven by demand," said lead author Rosamond L. Naylor, a professor of environmental Earth system science at Stanford University and director of the Stanford Program on Food Security and the Environment. "As long as we are a health-conscious population trying to get our most healthy oils from fish, we are going to be demanding more of aquaculture and putting a lot of pressure on marine fisheries to meet that need."

Fishmeal and fish oil

To maximize growth and enhance flavor, aquaculture farms use large quantities of fishmeal and fish oil made from less valuable wild-caught species, including anchoveta and sardine. "With the production of farmed fish eclipsing that of wild fish, another major transition is also underway: Aquaculture's share of global fishmeal and fish oil consumption more than doubled over the past decade to 68 percent and 88 percent, respectively," the authors wrote.

In 2006, aquaculture production was 51.7 million metric tons, and about 20 million metric tons of wild fish were harvested for the production of fishmeal. "It can take up to five pounds of wild fish to produce one pound of salmon, and we eat a lot of salmon," said Naylor, the William Wrigley Senior Fellow at Stanford's Woods Institute for the Environment and Freeman Spogli Institute for International Studies.

One way to make salmon farming more environmentally sustainable is to simply lower the amount of fish oil in the salmon's diet. According to the authors, a mere 4 percent reduction in fish oil would significantly reduce the amount of wild-caught fish needed to produce a pound of salmon – from 5 pounds of wild fish to just 3.9 pounds. In contrast, reducing fishmeal use by 4 percent would have very little environmental impact, they said.

"Reducing the amount of fish oil in the salmon's diet definitely gets you a lot more bang for the buck than reducing the amount of fishmeal," Naylor said. "Our thirst for long-chain omega-3 oils will continue to put a lot of strain on marine ecosystems, unless we develop commercially viable alternatives soon."

Naylor and her co-authors pointed to several fish-feed substitutes currently being investigated, including protein made from grain and livestock byproducts, and long-chain omega-3 oils extracted from single-cell microorganisms and genetically modified land plants. "With appropriate economic and regulatory incentives, the transition toward alternative feedstuffs could accelerate, paving the way for a consensus that aquaculture is aiding the ocean, not depleting it," the authors wrote.

Vegetarian fish

Fishmeal and fish oil are important staples at farms that produce carnivorous fish, including salmon, trout and tuna. But vegetarian species, such as Chinese carp and tilapia, can be raised on feed made from plants instead of wild-caught fish. That's one reason why farm-raised vegetarian fish have long been considered environmentally friendly.

In the early 1990s, vegetarian fish farms began adding small amounts of fishmeal in their feed to increase yields. However, between 1995 and 2007, farmers actually reduced the share of fishmeal in carp diets by 50 percent and in tilapia diets by nearly two-thirds, according to the PNAS report. Nevertheless, in 2007, tilapia and carp farms together consumed more than 12 million metric tons of fishmeal – more than 1.5 times the amount used by shrimp and salmon farms combined.

"Our assumption about farmed tilapia and carp being environmentally friendly turns out to be wrong in aggregate, because the sheer volume is driving up the demand," Naylor said. "Even the small amounts of fishmeal used to raise vegetarian fish add up to a lot on a global scale." Removing fishmeal from the diet of tilapia and carp would have a very positive impact on the marine environment, she added.

Regulating fisheries

On the policy front, Naylor pointed to the 2006 California Sustainable Oceans Act and the proposed National Offshore Aquaculture Act, which call for reductions in the use of fishmeal and fish oil in feeds. She also applauded plans by the National Oceanographic and Atmospheric Administration to develop a comprehensive national policy that addresses fisheries management issues posed by aquaculture. "No matter how much is done from the demand side, it is essential that there be regulation on the supply side as well," Naylor said. "You won't prevent the collapse of anchoveta, sardine and other wild fisheries unless those fisheries are carefully regulated."

Other co-authors of the PNAS study are Ronald W. Hardy, University of Idaho; Dominique P. Bureau and Katheline Hua, University of Guelph (Canada); Alice Chiu, Stanford; Matthew Elliott, Sea Change Management; Anthony P. Farrell and Ian Forster, Centre for Aquaculture and Environmental Research (Canada); Delbert M. Gatlin, Texas A&M University and the Norwegian Centres of Excellence; Rebecca J. Goldburg, Pew Charitable Trusts; and Peter D. Nichols, Commonwealth Scientific and Industrial Research Organisation (Australia).

The PNAS report was supported by the David and Lucile Packard Foundation.