http://www.cnn.com/2003/TECH/science/05/14/coolsc.disappearingfish/
Wednesday, May 14,
2003 Posted: 10:29 PM EDT (0229 GMT)
CNN
Study:
Only 10 percent of big ocean fish remain
By Marsha Walton
CAPTION #1:
Industrial fishing can reduce a particular fish population
to one-tenth its original size in only 10 or 15 years,
according to scientists.
Quote:
"Humans have always been very good at killing big animals."
-- Ransom Myers
(CNN) -- A new global
study concludes that 90 percent of all
large fishes have disappeared from the world's oceans in the
past half century, the devastating result of industrial fishing.
The study, which took
10 years to complete and was published
in the international journal Nature this week, paints a grim
picture of the Earth's current populations of such species
as sharks, swordfish, tuna and marlin.
The authors used data
going back 47 years from nine oceanic
and four continental shelf systems, ranging from the tropics
to the Antarctic. Whether off the coast of Newfoundland, Canada,
or in the Gulf of Thailand, the findings were dire, according
to the authors.
"I think the point
is there is nowhere left in the ocean not
overfished," said Ransom Myers, a fisheries biologist at
Dalhousie University in Halifax, Nova Scotia and lead author
of the study.
Some in the fishing
industry took issue with the tone of the report.
"I'm sure there
are areas of the world with that level of
depletion, but other areas are in good shape," said Lorne
Clayton, with the Canadian Highly Migratory Species Foundation,
a foundation that supports the sustainable development of the
tuna industry.
He said some abuses
of the past have ended: Long drift nets
are illegal, untended longlines are illegal, and many countries
adhere to elaborate systems of licensing, quotas and third party
observers working on boats.
Yet Clayton agreed
that there remains much room for improvement.
"It's important
to keep these issues in front of the public.
That puts pressure on the fisheries and agencies to keep
cleaning up their act," he said.
According to the report,
the big declines in the numbers
of large fishes began when industrial fishing started
in the early 1950s.
"Whether it is
yellowfin tuna in the tropics, bluefin
in cold waters, or albacore tuna in between, the pattern
is always the same. There is a rapid decline of fish numbers,"
Myers said.
Co-author Boris
Worm said the losses are having major
impacts on the ocean ecosystems.
The predatory fish
are like "the lions and tigers of the sea,"
said Worm, a marine ecologist with the Institute for Marine
Science in Kiel, Germany.
"The changes that
will occur due to the decline of these
species are hard to predict and difficult to understand.
However, they will occur on a global scale, and I think
this is the real reason for concern."
Going the way
of the dinosaurs?
In many cases, the
fish numbers plummeted fastest during
the first years after fleets moved into new areas, often
before anyone knew the drops were taking place.
A few decades ago,
longline fishing would catch about
10 big fish per 100 hooks. Now the norm is one fish per 100,
with fish about half the weight of earlier years, Myers said.
Longlining, among the
most widespread of fishing methods,
uses miles of baited hooks to catch a wide range of species.
Myers warned that the
world's great fish could go the way
of the dinosaurs if immediate action is not taken.
"Humans have always
been very good at killing big animals,"
Myers said. "Ten thousand years ago, with just some pointed
sticks, humans managed to wipe out the woolly mammoth,
saber tooth tigers, mastodons and giant vampire bats.
The same could happen in the oceans."
Some representatives
of the fishing industry say the
picture is not as bleak as the Nature authors indicate.
"For tuna, the
analysis is restricted to data from longline
fisheries that catch only relatively old individuals,
which comprise a small part of the stock," said Robin Allen,
of the Inter-American Tropical Tuna Commission.
According to the commission,
a greater reduction would be
expected in that age-group compared to the tuna stock as
a whole.
Worm said he hopes
this "big picture" study of the world's
fish populations will serve as a wake up call to governments,
global fishing conglomerates and environmental groups.
"People haven't
before seen how bad this is," said Worm.
"It doesn't make any sense, economically or ecologically,
to ignore this."
Solutions in
the water
While the numbers are alarming, Worm said there are solutions.
In the past when certain
fishing areas have been declared
off limits and fishing restrictions have been enforced,
certain fish and shellfish populations rebounded "amazingly
quickly," he said.
Haddock, yellowtail
and scallops have recovered in
different regions.
"The ocean is
full of surprises," Worm said. But with
numbers down so dramatically in every part of the world,
the situation cannot be ignored for long, he said.
Myers said many of
the world's fishing commissions and
governments have tried to wish away the problem for years.
Reversing the decline, he suggested, would require cutting
back fishing by as much as 60 percent.
Clayton said that technological
advances were already
responsible for improvements. Hi-tech equipment on fleets
from many developed countries reduce the by-catch, the
fish and other animals caught as by-products of the target fish.
But a huge technological
gap still exists between the fishing
fleets of rich and poor nations, Clayton said.
He said it makes economic
sense for the fishing industry
to adhere to conservation measures, and to look at the expansion
of aquaculture (fish farming) as part of the answer to dwindling
fish numbers.
