Warm water brings spate of weird fish

Squid, sharks, barracuda are among species newly arrived in Alaska waters

Posted: Sunday, September 25, 2005

An array of exotic fish and other unusual marine critters flooded the waters of Southeast Alaska this summer.

Seiners and troll fishermen reported sardines, anchovies, jumbo squid, sharks, barracuda and large concentrations of brilliantly hued open-ocean fish such as pomfret and opah.

The sightings are linked to warm ocean temperatures and winds blowing offshore waters toward the coast, scientists said.

The warm waters are not related to the El Niño cycle that has brought tropical currents carrying exotic species to Southeast Alaska in past years, scientists said.

"It looks like it may be associated with a long-term warming trend," said Bruce Wing, a Juneau-based oceanographer.

The ocean temperature in the Inside Passage and along the outer coastline in the Gulf of Alaska ranged two to three degrees - sometimes even higher - above average this summer, Wing said.

As the lab's curator and taxonomist, Wing is collecting specimens of what he calls the "strange and wonderfuls" at the National Marine Fisheries Service's Auke Bay Laboratory.

Wing said he has received more reports of "strange and wonderfuls" this summer than he has in the past, and he has started to pay careful attention.

"People are always asking us what we expect with climate change, and how it will affect our fisheries. It is only by keeping track of this - keeping records - that we can really find out what is happening," Wing said.

The reaction from Southeast Alaska fishermen to their catches this summer has been a mixture of fascination, worry and opportunism.

"Anyone who says there's no such thing as global warming needs to think again," said Paula Terrel, a Juneau troll fisherman who had trouble getting salmon on the line at times this summer because unusual numbers of sharks were biting at her bait.

Terrel said it wasn't unusual for her and her husband to catch 20 or 30 pomfret per day. "That was amazing to us. They are wonderful fish. And they are delicious," she added.

"There's definitely an incidence of fish we haven't seen before," said Scott McAllister, a Juneau purse seiner. "But over the years, there's always something different."

One of the most unique sightings in Southeast Alaska was large schools of sardines off Dall Island and in Chatham Strait and Cross Sound, among other locations. The species is not native to Alaska, but its historical range extends as far north as British Columbia.

Some Alaska seine fishermen beseeched state biologists unsuccessfully for a sardine fishery this summer.

"It just didn't seem like the right thing to do," explained Scott Kelley, the Alaska Department of Fish and Game's regional supervisor for commercial fisheries, of the department's rejection of their plea.

"This species is harvested in other jurisdictions (British Columbia, Oregon and Washington) and may already be fully exploited," Kelley said.

Sure enough, while Southeast Alaska seiners pulled up salmon nets holding 30 to 50 pounds of sardines, the Washington state sardine seine fishery was getting off to a lousy start.

For some time, the mature sardines that fetch high prices did not appear at the fishing grounds, a Washington state biologist said.

"It was questionable, until some of the older-structure fish started showing up," said Morris Barker, a marine resource manager for the Washington Department of Fish and Wildlife.

The apparent displacement of some sardine schools this summer is just one side effect of what could be significant shifts in the North Pacific ecosystem, scientists said last week.

Wing's counterparts at the Auke Bay lab and other research centers along the West Coast are trying to learn how a changing ocean could affect native fish stocks and entire ecosystems.

"It seems that the whole food web is showing responses to these changes," said Nathan Mantua, an oceanographer with the climate impacts group at the University of Washington.

In the Lower 48, warm ocean temperatures were connected to an ecological crisis this summer, he said.

The ocean off the coast of Washington, Oregon and California functions with a different nutrient cycle than the North Pacific and depends on an annual upwelling of plankton-rich cold water. The upwelling was a no-show this summer, and that had a vicious domino effect on hungry juvenile salmon and seabirds.

Scores of seabirds died and juvenile salmon counts were down significantly, biologists said.

"The warming hasn't shown any benefits for fish in the south. In Alaska, it's been a mixed picture. (Some) stream temperatures were inhospitable," Mantua said.

Meanwhile, ocean survival of salmon in the North Pacific appears to remain strong, with some exceptions.

"Warm temperatures (in the North Pacific) have come with really productive years for salmon," Mantua said.

It remains unclear what ocean temperature would be too high for salmon to tolerate in the Gulf of Alaska, he said.

In any case, if temperatures on land rise too high, they could spell trouble for the anadromous fish who cannot handle hot water.

Many of Southeast Alaska's healthy salmon runs originate in small snow and rain-fed streams, said Alex Wertheimer, a fisheries biologist with Juneau's Auke Bay lab.

In the future, "short, coastal streams could be in trouble," Wertheimer said.

• Elizabeth Bluemink can be reached at elizabeth.bluemink@juneauempire.com.

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