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WASHINGTON - Some 150 scientists
and specialists prominent in the study of the oceans
emitted a call for the immediate establishment of
marine reserves to replenish the planet's depleted
seas at a conference of the American Association for
the Advancement of Science, in San Francisco, California.
''The declining state of the
oceans and the collapse of many fisheries creates
a critical need for new and more effective management
of marine bio-diversity, populations of exploited
species and overall health of the oceans,'' say the
experts in consensus statement.
''Marine reserves are a highly
effective tool that can help alleviate many of these
problems''.
Most marine scientists believe
the seas are in serious trouble. They view coral bleaching,
changes in species composition, toxic algal blooms,
and fisheries collapse as symptoms of complex but
fundamental alterations in the health of marine ecosystems.
Intense fishing activity, along
with a rise in marine trade, the construction of ports,
and growing tourism all contribute to drastic transformations
of marine and coastal areas.
In Latin America, which is home
to the second largest coral reef in the world (Belize)
and one of the top five fishing industries (Chile
and Peru), the total fish catch was 21 million tons
in 1995, or 20 percent of the world total, according
to United Nations reports.
Currently, less than one percent
of the world's oceans are protected in reserves, where
all biological resources are protected through prohibitions
on fishing and the removal or disturbance of any living
or non-living marine resources.
But scientists say that the
few existing marine reserves have proven to be a useful
tool for restoring ocean health.
''Marine reserves work and they
work fast,'' says Jane Lubchenco, a professor at Oregon
State University who co-chairs a group of international
scientists that have been studying marine reserves
since 1997.
''It is no longer a question
of whether to set aside fully protected areas in the
ocean,'' she says, ''but where to establish them''.
Some 30 countries have designated
areas as marine reserves, but they do not all follow
the same guidelines. Marine reserves are sometimes
called ''ecological reserves'', or ''no-take areas''
which are different from other protected marine areas
because they do not allow any extractive activities.
Robert Warner, a scientist with
the University of California in Santa Barbara who
studies marine reserves, points out that just one
or two years after the creation of the conservation
areas, the average population densities of marine
life were 91 percent higher.
''The results are startling and
consistent,'' he said.
Biomass was 192 percent higher
and the average size of organisms was 31 percent higher,
Warner reports, adding that species diversity also
increased by 23 percent.
The size and abundance of exploited
species also increases in areas adjacent to reserves,
according to Callum Roberts, a marine scientist at
Harvard University.
Marine reserves differ from parks
on land because they serve as natural hatcheries,
replenishing populations regionally by the spillover
of larvae beyond reserve boundaries.
Most marine species move through
the water as larvae or spores, moved by tides and
currents. Dispersal distances of 20 to 50 kilometers
are not uncommon and dispersal of 500 to 1,000 kilometers
is possible in some cases due to currents, say scientists.
Fishers usually vigorously resist
the creation of marine reserves at first, but once
these communities realize that the reserve actually
increases the size and abundance of fish near the
reserves, they end up supporting the conservation
effort, says Lubchenco.
''While fishermen may lose access
to some areas, they will reap the benefits outside
the reserves,'' she says.
Roberts points to the case in
New Zealand where, despite violent opposition at the
outset, fishers have now become the champions of reserves
where they have seen populations of snappers increase
40-fold.
In the United States, three areas
totaling 17,000 square kilometers in the Gulf of Maine
in 1994 were closed to all fishing methods that put
a fish species, known as groundfish, at risk. Within
five years, says Roberts, their populations rebounded
to nine to 14 times their density in fished areas.
Scallops also flourished in the undisturbed habitat.
In Latin America, one of the
best known reserves is that of Ecuador's Galapagos
Islands, declared a Natural Heritage of Humanity site
by the United Nations Educational, Scientific and
Cultural Organization (UNESCO).
A 1998 law bans fishing by vessels
from mainland Ecuador or other nations in the 140,000-square-km
reserve. Only local fisherfolk may cast their nets,
says the legislation, and 50 percent of the profits
from tourism must go to conservation of the biodiversity
of the islands and the surrounding seas.
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