Fish numbers plummet in warming Pacific

<http://news.independent.co.uk/environment/article326752.ece>

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 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."