- LONDON (Reuters) - Large
predatory fish -- marlin, tuna and swordfish -- are disappearing from the
world's oceans, with their numbers down by 90 percent in the past 50 years,
Canadian scientists said on Wednesday.
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- "From giant blue marlin to mighty blue fin tuna,
and from tropical groupers to Antarctic cod, industrial fishing has scoured
the global ocean," said Ransom Myers, a biologist at Dalhousie University
in Canada.
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- "There is no blue frontier left."
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- Myers and his colleague Boris Worm estimate that compared
with when industrial fishing began in the 1950s, less than 10 percent of
large predatory fish species, the old men of the sea, have survived.
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- "This means that the larger, more sensitive species
like the sharks will go extinct unless we reduce fishing in a very large-scale
manner," Myers said in an interview.
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- The great fish, like the one immortalized in Ernest Hemingway's
"Old Man and the Sea" are not only dwindling in numbers, they
are also getting smaller.
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- Top predator fish are about one fifth to one half the
size they used to be. Many fish never get the chance to reproduce, according
to the researchers.
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- People had presumed there were untapped reservoirs of
large fish, but Myers said that is not true. He warned that the sustainability
of fisheries worldwide is being compromised.
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- "This calls for a reduction in fishing worldwide
so we can allow the natural diversity and fish species to persist in the
world's oceans," he said.
-
- "A minimum reduction of 50 percent of fish mortality
(the percentage of fish killed each year) may be necessary to avoid further
declines of particularly sensitive species."
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- As well as the big predators, there are also fewer large
ground fish such as cod, halibut, skate and flounder.
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- In a 10-year study, Myers and Worm examined data from
fisheries and scientific research institutes to estimate the number of
fish remaining in the world's oceans.
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- "It is a worldwide analysis...to find out what is
happening in the world's oceans," said Myers, whose research is published
in the science journal Nature.
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- If stocks are restored, he added, fishermen could get
more fish out of the oceans with a fraction of the effort. If they aren't,
the great fish will suffer the fate of the dinosaurs.
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