Scientists warn of rising Pacific Coast Ocean acidity
Pastor Dale Morgan
Scientists warn of rising Pacific Coast Ocean acidity*
By DAN CATCHPOLE,
Associated Press Writer
SEATTLE - A panel of marine scientists are warning that the Pacific
Coast's increasing acidity could disrupt food chains and threaten the
Pacific Northwest's shellfish industry.
The increasingly corrosive water threatens the survival of many
organisms, from microscopic plants and animals at the base of the food
chain to shellfish, corals and the young of some marine species, the
researchers told a congressional field hearing Tuesday at the Seattle
Aquarium.
The data indicates acidic water is appearing along the Pacific Coast
decades earlier than expected. The acidified water does not pose a
threat to humans, but it could dissolve the shells of clams, oysters and
other shellfish.
The acidic seawater is moving closer to shallow waters containing the
bulk of marine life, according to a recent article in the journal Science.
One of the article's authors, Christopher Sabine, said Tuesday he
watched small marine snails placed in water of similar acidity to that
recorded last summer off the northern California coast.
"We actually saw the shells dissolving off these living organisms. They
were dissolving off the terapods as they were swimming around," Sabine
said. Such creatures comprise as much as 40 percent of the Pacific king
salmon's diet.
Global ocean currents make the Pacific Northwest's coastal ecosystems
particularly vulnerable to acidification's effects, Sabine said.
A worldwide "conveyor belt" very slowly carries colder water from the
North Atlantic to the North Pacific. Along the way, the water
accumulates carbon dioxide from dead organisms, so it naturally has a
higher carbon dioxide concentration before man-made carbon dioxide is
added. A process known as 'up-welling' drags this water into shallower,
coastal areas.
"As long as CO2 continues to increase in the atmosphere, the oceans will
continue to absorb that," Sabine said. "What we're seeing is only going
to get worse."
Corrosive water could be disastrous for Washington state's shellfish
industry, noted one panel member, Brian Bishop, owner of Little Skookum
Shellfish Growers in Shelton, Wash. Washington state produces 85 percent
of all shellfish on the West Coast, Bishop said.
"This acidity dissolves calcium carbonate, which is the thing that
shells are made out of. If diatoms, corals, clams and oysters succumb to
this it not only wipes out the shellfish industry but potentially the
entire marine food chain," said Bishop, a fifth-generation shellfish
harvester.
The panel members said they did not know exactly how acidification will
affect Puget Sound and other Northwest coastal waters.
"We know very little about the biological effects of acidification on
the West Coast," said Terrie Klinger, of the University of Washington's
School of Marine Affairs. However, research has demonstrated that there
will be early and strong effects in Northwest coastal ecosystems, she added.
"We won't see a total collapse in food chains, but we will see
substitutions," Klinger said. "We may end up with food chains or food
webs that are highly undesirable and not productive for the means that
we use them today."