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.

The Shorenstein Asia-Pacific Research Center inaugurates the Stanford Kyoto Trans-Asian Dialogue on 10 and 11 September 2009, with the cooperation of the Stanford Japan Center and the generous support of the City of Kyoto and other donors.

The Dialogue gathers established and rising leaders in various sectors - industry, media, academia, politics - for annual discussion of critical issues of shared concern. Experts from Stanford University and specialists from around the region will launch the Dialogue sessions in focused topics within the annual theme. The 2009 Dialogue centers on the question of "Energy, Environment, and Economic Growth in Asia," with sessions on the Geopolitics of Energy in Asia, Energy Efficiency, Clean Technology, and Post-Kyoto Greenhouse Gas Emissions.

Benjamin Self, Takahashi Fellow in Japanese Studies, directs the effort. "The Dialogue brings together distinguished experts from Stanford and Silicon Valley, top specialists from around the region, and leaders in various fields. The meeting begins with an exploration of the influence of energy competition on international relations in Asia. After establishing the geopolitical context the group will explore new ideas on how to promote energy efficiency, clean technology, and the reduction of carbon emissions."

The Stanford Kyoto Dialogue creates a new regional forum, with diverse participation from not only Japan but also South Korea, China, Vietnam, Indonesia, India, and Singapore. Working with the City of Kyoto, famous for "green" initiatives, Stanford's Shorenstein APARC will support inventive collaboration on common challenges.

Jeremy M. Weinstein, an associate professor of political science, has been appointed Director for Democracy at the National Security Council (NSC). He will be responsible for democracy and governance-related issues and formulate broader U.S. government policies on global development.

"Jeremy brings a brilliant mind, inexhaustible energy, political savvy, and superb social science skills to his new position at the National Security Council," said Larry Diamond, director of the Center on Democracy, Development, and the Rule of Law (CDDRL) at Stanford's Freeman Spogli Institute for International Studies (FSI). "In addition, his recent service on the Committee on the Evaluation of USAID Democracy Assistance Programs and his field research and experiments on governance in Africa should help him bring a creative approach to U.S. policies to advance democracy and improve governance around the world."

Weinstein's new position follows four other Stanford FSI appointments to the Obama administration. Political Science Professor Michael McFaul and Elizabeth Sherwood-Randall, a former senior research scholar at the Center for International Security and Cooperation (CISAC), also work at the NSC as special assistants to the President. McFaul heads Russian and Eurasian affairs and Sherwood-Randall is responsible for European affairs. Law Professor Mariano-Florentino Cuellar serves on the White House Domestic Policy Council in charge of directing criminal justice and immigration policy, and Paul Stockton, a former CISAC senior research scholar, is an assistant secretary of defense responsible for homeland defense and Americas' security affairs.

Weinstein, who is on leave from Stanford, is a faculty member at CDDRL and CISAC. His academic research focuses on civil wars, ethnic politics, the political economy of development, democracy and Africa.

Political Science Professor Scott D. Sagan, CISAC co-director, said although Weinstein is one of the nation's leading scholars on African politics his interests and expertise are much broader. "Jeremy has written compelling studies of the causes of civil war and the roots of conflict resolution and democratic reform," he said. "He will bring important insights from social science and history to help Washington policy-makers address complex policy problems throughout the developing world."

FSI Director Coit D. "Chip" Blacker, the Olivier Nomellini Professor in International Studies, who served under former President Bill Clinton, said the Obama administration is fortunate to have someone of Weinstein's caliber. "Jeremy's intellectual drive, his field experience with conflict-ridden countries, and his passion for democracy and better governance will help strengthen U.S. relations with states in transition and improve prospects for political and economic advance."

In 2008, during Obama's campaign, Weinstein served as an advisor on development and democracy. He continued working during the transition as a member of the National Security Policy Working Group and the Foreign Assistance Agency Review Team.

Weinstein, 34, is the author of Inside Rebellion: The Politics of Insurgent Violence, which received the 2008 William Riker Prize for the best book on political economy. His most recent book is Coethnicity: Diversity and the Dilemmas of Collective Action, published in 2009. He has also published articles in a variety of journals including Foreign Affairs, the American Political Science Review (APSR), the Journal of Conflict Resolution, Foreign Policy and the Journal of Democracy. Two articles in APSR, titled, "Handling and Manhandling Civilians in Civil War" and "Why Does Ethnic Diversity Undermine Public Goods Provision," received, respectively, the 2005 Sage Prize and 2007 Gregory Luebbert Award, and the 2008 Heinz Eulau Award and the 2008 Michael Wallerstein Award. In 2008, Weinstein also received the Dean's Award for Distinguished Teaching at Stanford.

Weinstein earned a bachelor's with high honors from Swarthmore College in 1997, and a master's and doctorate in political economy and government from Harvard University in 2001 and 2003, respectively. He is a native of Palo Alto, California.

David G. Victor and Richard K. Morse explain why coal, the world's fastest growing fossil fuel and leading source of greenhouse gas emissions, is here to stay and how climate policy can tackle this problem. Their piece is also featured in Engineering World's October/November 2009 issue.