- A billion-dollar survey of the world's oceans has so
far pinpointed 38,000 marine species - and identified new fish at the rate
of two a week. The census of marine life, a concerted effort by hundreds
of scientists from more than 70 nations, is in effect the first hi-tech
inventory of life in the so called "blue planet". Oceans cover
70% of the globe. But marine scientists have been pointing out for years
that the surface of Venus has been better mapped than the world under the
oceans.
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- The latest "end of term report" by the census
scientists assembles data from more than 5.2m new and existing records,
and maps the distribution of the 38,000 species. Details of the survey
will be unveiled at a meeting in Hamburg next week.
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- Scientists in Australia, China, Canada, Europe, India,
Japan, New Zealand, South America and sub-Saharan Africa are to form nine
new regional networks to create a new "information seaway". But
the worldwide bid to probe life in the seas has hardly begun.
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- "We have barely skimmed the surface," said
Frederick Grassle, of Rutgers University in the US, who chairs the international
scientific steering committee of the census.
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- "Humans have explored less than 5% of the world's
oceans, and even where we have explored, life may have been too small to
see. Thus, opportunities abound to discover species and increase our knowledge
of abundance and distribution."
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- Life on earth is a mystery: life in the oceans is an
even deeper mystery. The seas cover long sloping continental shelves rich
in nutrients that drain from the land; huge, muddy abyssal plains fertilised
by detritus from the surface; ocean trenches far deeper than the Grand
Canyon, and a vast chain of volcanic mountains known as the mid-Atlantic
ridge, where submarine hot springs support colonies of living creatures
were discovered only about 25 years ago.
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- All of these habitats are home to living things.
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- So far, taxonomists have named and described around 230,000
species of marine creature. But there could be 10 times as many, still
to be identified.
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- At the same time, many ocean species are under threat.
Commercial fishing has damaged and depleted the north Atlantic cod and
the bluefin tuna and reduced the world's whale population to a hundredth
of its original count.
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- Many of the world's coral reefs - shelter for rich ecosystems
of lagoon creatures - are threatened by global warming, habitat destruction
and pollution.
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- The push for new commercial species now threatens deep
ocean fish such as the orange roughie, which take decades to reach maturity.
As commercial species disappear, so complex ecological networks are disrupted.
So the the census is part of a concerted international effort to make a
detailed map of life on the biggest - and most unexplored - region of the
planet.
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- The payoff so far is a $9.5m (£5.1m) ocean biographic
information system that pinpoints 95% of all records so far on or near
the surface of the sea.
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- Less than 0.1% of the records are from the bottom half
of the water column. So there are depths of knowledge still to be plumbed.
Researchers calculate that a creature collected from below 2,000 metres
is about 50 times more likely to be new to science than one found in the
first 50 metres.
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- In this year alone, the census has added 106 species
of marine fish to the database - an average of more than two new species
a week. The total of known fish species in the sea now stands at 15,482.
There could be another 5,000, awaiting discovery. The database has also
counted 6,800 species of zooplankton, animals that drift with the ocean
currents. They could identify another 6,000 over the next decade.
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- The discoveries rest on a whole range of new submarine
technologies, from robot submersibles to a network of seafloor "listening
posts".
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- Some scientists have concentrated on collecting specimens
from 6,000 metres below the surface, off the coast of Angola, or from the
hidden world underneath the Antarctic ice shelf.
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- Others have "tagged" open ocean species, to
provide the first ever map of marine "highways" for sharks, turtles
and marine mammals. Biologists have found not just new species of octopus,
but a new genus - a much larger grouping - of these puzzling animals in
the Southern Ocean. Others have been examining colonies of rhodoliths -
a kind of coral-like marine algae that moves like tumbleweed - in southern
Alaska. Remotely operated vehicles with robot arms have picked up a clam
that survives on methane deposits on the sea floor off the coast of Chile,
and a new species of mollusc that lives down thermal vents in the Indian
Ocean.
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- Researchers "listening" to salmon in northern
California also picked up signals from tagged green sturgeon - rarest of
the 26 sturgeon species - as they travelled to the Canadian coast.
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- Other researchers have explored not the present but the
past, to map the change in sea fish populations.
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- Records from 400 years ago show that cod taken by hand
line from the side of a fishing boat could weigh as much as 80lbs (about
36kg). With the advent of trawl nets, more cod were taken but the average
size began to fall dramatically.
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- Oceanic white tip shark numbers in the Gulf of Mexico
have fallen by 99% in the last 50 years. Shark populations in the north
Atlantic have fallen by from 40% to 90%, depending on the species. Hardest
hit has been a once-feared predator, the hammerhead.
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- Catches of the day
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- Biologists identified a new species of grenadier in the
Tasman Sea, a new species of scorpionfish in the IndoPacific region and
a strange finned octopod they nicknamed "Dumbo" at 3,000 metres
on the mid-ocean ridge. But other signals from the seas in the past two
years have been less cheerful. These include:
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- * Carbon-dioxide exhausts from human industry are not
just creating warmer oceans, they are gradually increasing their acidity,
scientists reported in August. This could affect corals and marine shellfish
- and subsequently the species that depend on them.
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- * American shoppers face an identity crisis. Researchers
found in July that 77% of all fish sold in the US as red snapper were in
fact some other species.
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- * Marine biologists have identified a "lost world"
in the Arctic ocean. The Canada basin is a vast pool of still water walled
in by steep ridges far below the surface. In one cruise, researchers picked
up 400 unidentified species.
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- * In June, British scientists calculated that 30% of
the world's seas could be protected from all fishing at a cost of £8bn
a year. This is roughly what tourists spend each year on ocean cruises.
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- * Project Neptune (North-east Pacific time series underwater
networked experiments) is to establish a network of 30 sea-floor "laboratories"
100kms apart and up to 3,000 metres deep, connected by 3,000kms of fibre-optic
cable. Students will be able to link to the submarine laboratories via
the internet.
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- * The leatherback turtle has outlived the dinosaurs by
65m years. But scientists warned last year that it could be on the road
to extinction in 10 to 20 years. Only about 1,500 females now nest in the
Pacific.
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- Guardian Unlimited © Guardian Newspapers Limited
2004
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- http://www.guardian.co.uk/conservation/story/0,13369,1357322,00.html
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