UW Report: Ecosystem Based Management Not Enough to Reverse Coastal Habitat Decline

January 17, 2008
Mangrove stumps in pond
Tangalan Pond – Mangrove stumps remain in extensive aquaculture pond in Tangalan, Aklan, in central Philippines. Photo by J. Primavera.

Worldwide coastal ecosystems and habitats will continue to decline unless economists and ecologists work together to improve current methods to assess coastal ecosystem benefits, according to an article today in the global scientific journal, Science.

Edward B. Barbier, the John S. Bugas Professor of Economics in the University of Wyoming College of Business Department of Economics and Finance, says recent scientific studies have documented the alarming decline in worldwide coastal ecosystems and habitats.

Barbier is the lead author among 15 others whose research on the subject ("Coastal ecosystem-based management with non-linear ecological functions and values"), appears in the weekly publication of the American Association for the Advancement of Science.

Barbier says recent research indicates that global coastal population densities are nearly three times those of inland areas and are rapidly rising. As coastal and marine habitats come under more pressure from human exploitation, economists, ecologists and other scientists need to collaborate to improve the understanding of the myriad "benefits" lost through such overuse to better inform coastal and marine management decisions, he says.

"The long-term sustainability of these populations depends upon coastal ecosystems and the services they provide, such as storm buffering, fisheries production and enhanced water quality," he adds. "To arrest coastal habitat decline, concerned international organizations and scientists are calling for a new approach."

He says ecosystem-based management (EBM) is a way to reconcile the decline in vital coastal ecosystem services with continuing human development pressures. Barbier and his colleagues endorse the general need for coastal EBM, but their research indicates that this strategy is "likely to fail" unless others, such as economists and ecologists, work together.

"Too often, poor ecological data lead to inaccurate valuation of these benefits, resulting frequently in an ‘all or none' choice of either preserving or converting all coastal habitats to human use," Barbier says. "This ‘all or none' outcome is at odds with EBM strategies, which are trying to find acceptable compromises between conservation and development."

To illustrate the importance of this dilemma, Barbier and his team focus on the key ecosystem service of coastal wetlands acting as "natural barriers" to the economic damages caused by frequent coastal storm events. In recent years, this critical "storm prevention" service of coastal habits -- such as mangroves and marshlands -- has received considerable attention by the massive changes inflicted by events such as the December 2004 Indian Ocean tsunami, the August 2005 Hurricane Katrina along the Gulf Coast and the November 2007 Cyclone Sidr in coastal Bangladesh.

From field studies of mangroves, salt marshes, seagrass beds, near shore coral reefs, and sand dunes, the study shows that the ability of these critical habitat to "attenuate" or break up, incoming storm surges and waves declines considerably as more habitat is lost.

Barbier's research in Thailand demonstrates how mangroves successfully protect coastal regions.

"We show that by valuing correctly this ‘natural barrier' service, the best land use is neither complete conversion of the mangroves to an alternative use, such as commercial shrimp aquaculture, nor preservation of all the mangrove forest," he says. "Instead, the best coastal management policy is a mix of these development and conservation options. In fact, the outcome from our Thailand mangrove valuation example corresponds to ‘best practice' guidelines for mangrove management in Asia, which recommend that ideal mangrove-pond ratios should not exceed 20 percent of the habitat area converted to ponds."

The Thailand mangrove study illustrates that the way in which ecological and economic analysis is combined to estimate the values of various ecosystem services can have a large impact on coastal EBM outcomes.

"Researchers need to be aware how incorrect assumptions underlying ecological and economic analysis might inadvertently force EBM decision-making into a simple ‘all or none' choice," Barbier says. "If the analysis is done correctly, however, then the right balance between development and conservation objectives can be achieved in the world's heavily used coastal areas."

This is the third time within a year that Barbier's research work on coastal ecosystems has been published in Science. Previous work included a study showing how the loss of biodiversity is reducing the ocean's ability to produce seafood, and every species lost causes a faster unraveling of the overall ecosystem. Barbier was part of that study which received worldwide attention, including a recent cover story in Time magazine.

Rob Godby, UW Department of Economics and Finance chairman, says for any UW researcher, such as Barbier, to publish three articles in Science in a year's time is highly unusual and possibly unprecedented. He adds that the fact that a UW economist has accomplished this suggests that an important shift may be occurring within the global scientific community.

Finding solutions to complex environmental management problems -- from global warming to coastal and marine degradation to developing new energy resources -- requires collaboration among ecologists, economists and other natural scientists, Barbier says.

"In other words, both the policy making community and academic researchers want to see such collaboration yield results -- and fast," he says. "My own research has focused on this interface between ecology and economics. UW researchers are very much aware of this ‘paradigm' shift in the global scientific community and in recent years have been trying to capitalize on it."

He adds that collaboration among UW disciplines has aided his research. Ruckelshaus Institute of Environment and Natural Resources Director Harold Bergman has stressed the need for collaborative scientific efforts, particularly with regard to critical environmental problems faced in Wyoming and the West, Barbier says. Bill Gern, UW vice president for research and economic development, has actively supported the Department of Economics and Finance's efforts to recruit economists with the interest and research expertise to collaborate with ecologists, he adds.

Additionally, UW Botany Professor Steve Jackson invited Barbier on to the Internal Advisory Committee of the NFS EPSCoR (National Science Foundation's Experimental Program to Stimulate Competitive Research) Ecology Program to expand ecology and economics collaboration at UW.

"The new School of Energy Resources is built on the basis of interdisciplinary research -- again, we need such collaborative research across the physical, economic and natural sciences to find new and sustainable solutions to exploiting Wyoming's energy resources," he adds.

The past few years Barbier has collaborated with ecologists and other economists on a major National Academy of Sciences report, two projects funded by the National Center of Ecological Analysis and Synthesis (NCEAS) and several joint research projects. He also served on scientific advisory boards, including as an associate editor of the Ecology Society of America's journal, Frontiers in Ecology and Environment. His three Science articles are direct results of the two NCEAS project collaborations.


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