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Ocean 'dead zones' rising - UN
20/10/2006 12:09 - (SA)
Nairobi - The number of "dead zones" in
the world's oceans may have increased by a third in just two
years, threatening fish stocks and the people who depend on
them, the UN Environment Programme said on Thursday.
Fertilizers, sewage, fossil fuel burning and other
pollutants have led to a doubling in the number of
oxygen-deficient coastal areas every decade since the 1960s.
Now experts estimate there are 200 so-called ocean dead
zones, compared with 150 two years ago.
"Some successes are being scored but in other areas - like
sewage, nutrients from fertilizer run off, animal wastes and
atmospheric pollution; sediment mobilization and marine litter
- the problems are intensifying," UNEP Executive Director Achim
Steiner said in a statement.
The first "dead zones" - where pollution-fed algae remove
oxygen from the water - were found in northern latitudes like
the Chesapeake Bay on the US East Coast and the Scandinavian
fjords.
The Gulf of Mexico
Today, the best known is in the Gulf of Mexico, where
fertilizers and other algae-multiplying nutrients are dumped by
the Mississippi River.
Others have been appearing off South America, Ghana, China,
Japan, Australia, New Zealand, Portugal and Britain.
The UNEP said in a statement that experts warn "these areas
are fast becoming major threats to fish stocks and thus to the
people who depend upon fisheries for food and livelihoods."
The full list is expected to be published early next year,
but the preliminary findings were released on Thursday at an
international marine pollution conference in Beijing, China,
which gathered delegates from more than 100 nations.
The meeting also heard some good news from scientists
studying the recovery rates of coral reefs damaged by bleaching
in the late 1990s by high sea temperatures.
Coral reefs get bleached when warm water forces out tiny
algae that live in the coral, providing nutrients and giving
reefs their vivid colours. Without the algae, corals whiten and
eventually die.
"The new studies indicate healthy ecosystems exposed to
minimal contamination are likely to recover and survive better
than those stressed by pollution, dredging and other human-made
impacts," Steiner said.
UNEP said the overall findings were given even more urgency
by new modelling that shows up to 90% of the world's
tropical coasts may be developed by 2030.
"Climate change, and the need to build resilience into
habitats and ecosystems so they can cope with the anticipated
increase in temperatures likely to come, now represents a
further urgent reason to act," Steiner added
Thursday's meeting came just over two weeks before the start
of global warming talks under the UN Framework Convention on
Climate Change due to begin in Nairobi, Kenya on November 6.
- Reuters
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