Fish numbers plummet in warming Pacific
Independent Online Edition > Environment
Disappearance of plankton causes unprecedented collapse in sea and bird life
off western US coast
By Geoffrey Lean in San Francisco
Published: 13 November 2005
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
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."