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From the Editors of E/The Environmental Magazine
Fishing Out the Oceans
Are fish farms a better source for satisfying growing appetites?
What are the pros and cons of marine aquaculture, of raising ocean fish instead of catching them in the wild?
Jeanne L., Norwalk, Conn.
Marine aquaculture, an age-old practice in parts of Asia, has grown in popularity in western countries in recent years in response to dwindling supplies of wild fish in the world’s oceans. High-tech fishing practices, such as drift netting, have led to a potentially irreversible decline in populations of key seafood species, according to the Pew Oceans Commission, a blue-ribbon panel of fisheries and marine biology experts. Some shark, tuna and cod species have declined as much as 90 percent in the past few decades.
Most marine biologists agree that as human population continues to grow worldwide, there will not be enough wild-captured fish to meet demands for seafood. Aquaculture “the propagation and rearing of aquatic organisms in controlled or selected environments,” as defined by the U.S. National Oceanic and Atmospheric Administration is seen by many as the best way to fill the gap. Currently aquaculture supplies about 30 percent of the world’s seafood, up from just four percent 30 years ago.
Aquaculture can reduce the need for seafood imports and provide jobs for coastal communities, according to James McVey of NOAA’s Sea Grant program. “The U.S. currently brings in $10 billion in seafood from other countries,” McVey says. “With increased production capacity, our higher yields from aquaculture will bring down this trade deficit.”
But aquaculture’s downsides give many scientists pause.
Studies indicate that, despite the promise of reducing pressures on wild fish, aquaculture requires two pounds of wild-caught fish as feed to make one pound of farmed fish. Further, says SeaWeb, breeding farms where thousands of fish, and their waste, are concentrated breed diseases that can then escape and contaminate wild fish populations.
To control such outbreaks, many fish farmers treat their stocks with antibiotics that can also make their way into the oceans and wreak havoc. The farmed fish themselves also escape from their pens and interbreed with and take over habitat traditionally occupied by wild populations. Another problem with aquaculture, according to SeaWeb, is its destruction of natural habitats. The group blames shrimp farming, for example, for destroying coastal mangrove forests in the Philippines, Thailand and elsewhere.
But many scientists do feel that aquaculture has the potential for helping the world’s marine ecosystems rebound if it is done conscientiously. Among other things, SeaWeb recommends that fish farmers avoid using drugs to fight disease and that governments do more to regulate and police aquaculture operations to make sure otherwise pristine waters are not fouled and sensitive coastal ecosystems are not damaged.
The greatest power to end irresponsible aquaculture rests with consumers, according to the Monterey Bay Aquarium’s Seafood Watch program. The organization’s website offers tips on which kinds of farmed seafood to buy and which to avoid. While no one person’s choices will improve the environment dramatically, collectively consumers can play a role in how producers treat the ecosystems they utilize.
For more information:
• NOAA: www.nmfs.noaa.gov/mediacenter/aquaculture/.
• SeaWeb’s Ocean Briefings Marine Aquaculture: www.seaweb.org/resources/briefings/aquaculture.php.
• Monterey Bay Aquarium’s Seafood Watch Regional Seafood Guides: www.mbayaq.org/cr/SeafoodWatch/web/sfw_regional.aspx.
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