- A catastrophic collapse in sea and bird life numbers
along America's Northwest Pacific seaboard is raising fears that global
warming is beginning to irreparably damage the health of the oceans.
-
- Scientists say a dramatic rise in the ocean temperature
led to unprecedented deaths of birds and fish this summer all along the
coast from central California to British Columbia in Canada.
-
- The population of seabirds, such as cormorants, auklets
and murres, and fish, including salmon and rockfish, fell to record lows.
-
- This ecological meltdown mirrors a similar development
taking place thousands of miles away in the North Sea, which The Independent
on Sunday first reported two years ago. Also caused by warming of the water,
the increase in temperatures there has driven the plankton that form the
base of the marine food chain hundreds of miles north, triggering a collapse
in the number of sand eels on which many birds and large fish feed and
causing a rapid decline in puffins, razorbills, kittiwakes and other birds.
-
- The collapses in the Pacific are also down to the disappearance
of plankton, though the immediate cause for this is different. Normally,
winds blow south along the coast in spring and summer, pushing warmer surface
waters away from the shore and allowing colder water that is rich in nutrients
to well up from the sea bottom, feeding the microscopic plants called phytoplankton.
These are eaten by zooplankton, tiny animals that in turn feed fish, seabirds
and marine mammals.
-
- But this year the winds were extraordinarily weak and
the cold water did not well up in spring as usual. Water temperatures soared
to 7C above normal, which delighted bathers but caused the whole delicate
system to collapse. The amount of phytoplankton crashed to a quarter of
its usual level.
-
- "In 50 years this has never happened," said
Bill Peterson, an oceanographer with the US government's National Oceanic
and Atmospheric Administration, NOAA, in Newport, Oregon.
-
- Record numbers of dead seabirds soon washed up on beaches
along the coast. There were up to 80 times more dead Brandt's cormorants,
a fishing bird, than in previous years.
-
- Tests showed the birds died of starvation. "They
are not finding enough food, and so they use up the energy stored in their
muscles, liver and body fat," said Hannah Nevins, who investigated
similar mass deaths in Monterey Bay.
-
- Many fear the ecological collapse is a portent of things
to come, as the world heats up. A Canadian Government report noted that
ocean temperatures off British Colombia reached record levels last year
as well, blaming "general warming of global lands and oceans".
And Professor Ronald Neilson, of Oregon State University, added: "The
oceans are generally warming up and there are all sorts of signs that something
strange is afoot."
-
- Copyright © 2005 Independent News & Media (UK)
Ltd.
|
