High Tech Methods Decimating Fish Populations
Seascape
By Cat Lazaroff
BOSTON, Massachusetts, February 18, 2002 (ENS) - New fishing methods
based on military technology are accelerating the decline of
commercial fish populations, a new study suggests. Despite increased
fishing efforts, catches continue to decline in the North Atlantic and
other prime U.S. fishing grounds, shows research detailed this week at
a scientific conference in Boston.
Faced with dwindling stocks and rising demand for seafood, fishers are
employing new technologies that leave no safe haven for fish,
including the application of military technologies, spotter planes and
round the clock exploitation.
At the annual meeting of the American Association for the Advancement
of Science (AAAS) in Boston on Sunday, an international group of
leading marine scientists presented examples of overfishing from
around the world, arguing that new technologies and increasing fishing
efforts make the need for marine reserves imperative.
"New technologies and fishing effort have peeled the lid off the
oceans," said University of York scientist Callum Roberts. "If we want
to keep seafood on our plates, we need to put back refuges so some
fish survive long enough to reproduce."
For most of human history, fish and other marine species had naturally
protected areas: places inaccessible to fishing because they were too
remote, too deep or too dangerous to fish.
But civilian applications of military technologies, such as those
developed for submarine warfare and espionage, have grown by leaps and
bounds since the end of the cold war. These transferred technologies
include sonar mapping systems that reveal every crack and contour of
the seabed in exquisite detail.
The U.S. Geological Survey is now publishing maps that are enabling
fishers to penetrate deep into regions once considered too difficult
to fish. Private companies are also weighing in, selling the secrets
of the seabed for short term profit.
Guided by precision satellite navigation systems, fishers can now drop
nets into previously unseen canyons, or land hooks on formerly
uncharted seamounts.
"Such places may be the last refuges of vulnerable species like skates
or rockfish," warned Roberts.
Fishers are also looking to the skies for better catches. Off the U.S.
East coast, the Atlantic swordfish fleet receives daily faxes from the
National Oceanic and Atmospheric Administration, showing satellite
images of sea surface temperatures on the fishing grounds. These maps,
along with temperature and depth sensors carried by boats, allow the
fleet to target the places where swordfish are most vulnerable.
The same technology guides the bluefin tuna fleet to the best fishing
areas, and spotter planes help boats pursue schools to the last fish.
"The modern fishing armory has vastly expanded," said Yvonne Sadovy of
the University of Hong Kong. "The boats of today are larger, faster,
stronger and can fish in conditions that would have been impossibly
dangerous 100 years ago."
They fish deeper, for longer and employ nets that can penetrate areas
of rough seabed, moving rocks up to three meters (10 feet) in diameter
and weighing up to 16 metric tons.
"Not all new fishing technologies are hi-tech," said University of
Hawaii researcher Charles Birkeland. "Modern improvements can be just
as devastating to fish stocks."
In islands throughout the Pacific, for example, fishers have long
valued the huge and docile bumphead parrotfish. By day, these wary
fish would keep their distance from spearfishers, so the take was
never very high.
But in recent years, spearfishers equipped with scuba equipment have
begun targeting the parrotfish at night when they sleep in shoals in
shallow reef lagoons.
"Spearguns and nightlights are as lethal to bumphead parrotfish today
as rifles and railroads were for American Plains bison in the 19th
Century," Birkeland said.
The unsustainable pursuit of larger and more desirable coral reef
species is also being fueled by the growth of international markets.
"Greater prosperity and demand for live food fish in South-East Asia
has driven prices so high that it is profitable to pursue fish to the
farthest corners of the world," noted Sadovy. "Because so many species
are targeted, fishing operations can remain economically viable far
beyond the point where the most vulnerable species have been
eliminated."
As fishers expand their reach, the importance of creating natural
refuges for sustaining breeding stocks increases, the researchers
argue.
"When there is no place for fish to hide, we can devastate entire
populations. There is evidence that severely overexploited species may
not recover, even decades after depletion," said University of
Dalhousie scientist Jeff Hutchings.
For example, more than 100 tons of black-lipped pearl oyster were
taken from Pearl and Hermes Reefs in the Northwest Hawaiian Islands in
1927. Just six individuals were found during an intensive survey late
in the year 2000, 63 years after the harvest.
In Canada, northern cod were depleted to a few percent of their former
abundance in the early 1990s, and there is still little sign of
recovery.
"We are realizing, too late in some cases, that severe depletion can
undermine population resilience by impairing reproduction, reducing
recruitment of young animals, degrading habitat integrity, and
altering behavior and interactions with other species," said Howard
Choat of James Cook University. "This further points to the need to be
proactive so that populations don't reach this point of no return."
"We are pushing fisheries off the edge of viability, and species to
the edge of extinction," added Birkeland. "We must recreate the
refuges of old by establishing networks of marine reserves."
New evidence indicates that fully protected refuges can help protect
stocks from reaching the point of no return by providing safe havens,
protecting habitats and by exporting fish and their offspring to
surrounding fishing grounds.
"Without such marine reserves, the ocean's future looks bleak,"
Roberts concluded.
Their work found support Saturday when scientists presented a new
portrait of the state of fisheries in the North Atlantic, showing that
over the last 50 years, the catch of preferred food fish species such
as cod, tuna, haddock, flounder and hake has decreased by more than
half, despite a tripling in fishing effort.
The study shows that large scale fishing in the North Atlantic has
undermined the ocean's ability to sustain further catches.
"The only way we are maintaining yield is by increasing effort," said
Dr. Daniel Pauly of the University of British Columbia Fisheries
Centre, and the head of the large international project behind
Saturday's presentation at the AAAS meeting. "But you need fish to
make fish, and so we have created a massive reduction in
productivity."
Serial depletion of large predatory fishes at the top of all marine
food webs means the major fisheries are now invertebrates. "We are
fishing for bait and headed for jellyfish," warned Pauly.
Today, the large fish found in North American markets are being
imported from developing regions of the world such as West Africa,
South East Asia and other areas masking the crisis in local waters,
added Reg Watson of the University of British Columbia.
"We are paying fishers in other oceans to grind down their marine
ecosystems for our consumption," Watson said. "This is a serious
concern for global food security."
Pauly explained that the next steps are a substantial reduction of
fishing fleets, eventual abolition of subsidies to industrial
fisheries, and restoration of the oceans' depleted resources through
the establishment of networks of no take marine reserves.
"In order to restore productivity to a fishery, the broader ecosystem
with its many parts needs to be conserved," Pauly concluded.
An international coalition of conservation groups recently sponsored a
poll that interviewed 750 residents of New England and Atlantic Canada
regarding their support for marine reserves. The poll found that 74
percent of New England respondents and 73 percent of Canadian
participants support establishing fully protected no take ocean areas
that bar all fishing, mining, and other potentially damaging
activities.
"This new poll shows that there is strong support among those who live
in New England and Atlantic Canada for establishing fully protected
areas in the ocean that prohibit all extractive activities, including
commercial and recreational fishing," said Priscilla Brooks, director
of the marine resources project at the Conservation Law Foundation.
"Both the United States and Canadian governments need to create public
processes that will create fully protected areas in the ocean, which
are science based, participatory and also give full consideration to
fishing industries," added Robert Rangeley, Atlantic marine program
director of World Wildlife Fund - Canada.
More information on declining fish catches in the North Atlantic is
available at: http://www.seaweb.org/AAAS2002/
© [24]Environment News Service (ENS) 2001. All Rights Reserved.