What are the pros and cons of marine aquaculture, of raising
fish instead of catching them in the wild?
L., Norwalk, CT
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. According to the Pew Oceans Commission, a blue-ribbon
panel of fisheries and marine biology experts, high-tech fishing
practices, such as drift netting, have led to a potentially
irreversible decline in populations of key seafood species.
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 (NOAA), 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 4 percent
30 years ago.
James McVey of NOAA’s Sea Grant program says aquaculture
can reduce the need for seafood imports and provide jobs for
coastal communities. “The U.S. currently brings in $10
billion in seafood from other countries,” he said. “With
increased production capacity, our higher yields from aquaculture
will bring down this trade deficit, and improve food security—where
we’re not as reliant on other nations for food.”
But aquaculture’s down sides give many scientists pause.
Studies indicate that, despite the promise of reducing pressures
on wild fish, aquaculture requires two pounds of wild-caught
fish to use 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 major 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
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.
According to the Monterey Bay Aquarium’s “Seafood
Watch” program, the greatest power to end irresponsible
aquaculture rests with consumers. The organization’s
Web site 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
CONTACTS: 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
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