LA Times, Oct 2nd, 2007
California | Local News
Neurotoxin ruled out in whale deaths
By Steve Chawkins, Los Angeles Times Staff Writer
With test results in hand, scientists have ruled out a neurotoxin that had been their best bet to explain why three blue whales were killed recently in ship collisions off Southern California.
Their working theory had been that whales disoriented by the toxin were unable to avoid freighters and tankers inadvertently bearing down on them.
Scientists now believe that the endangered cetaceans were simply feeding in the wrong places at the wrong time, said Michelle Berman, assistant curator of vertebrate zoology at the Santa Barbara Museum of Natural History.
"We thought that maybe there was some other reason that these animals were getting hit," Berman said Monday. "Now we can rule out domoic acid."
The acid -- which is produced by a certain type of sea algae -- was not present in tissues extracted from the most recent dead blue whale, a 60-footer that was found in the Santa Barbara Channel and towed to a beach at Point Mugu for scientific examination on Sept. 22.
The freshest of the three whales, it was the only one to yield tissues that were not too decomposed for laboratory analysis.
In 1998, domoic acid was pinpointed as a poison that attacked the brains of dolphins and sea lions off the Central Coast, causing them to lose control of their movements, struggle for breath and sometimes wash ashore.
But the kind of algae that typically produces domoic acid has not recently been found in significant concentrations in the area, Berman said.
The two whales found in the Santa Barbara Channel had numerous broken bones, supporting the ship-collision theory. Collision is strongly suspected in the death of the third whale, which was found in Long Beach Harbor but towed out to sea before experts could get a detailed look at it.
Berman, a biologist, said a team of marine specialists had "completely ruled out" sonar used in Navy training exercises as a contributing factor in the deaths.
Two of the whales died days before the exercises began off San Clemente Island on Sept. 11, and the whale at Point Mugu had no telltale trauma inside or around the ears, she said.
Certain frequencies of sonar have been linked to whale deaths in the Bahamas and elsewhere. At the request of the Natural Resources Defense Council, the California exercises were halted by a federal judge. On Aug. 31, an appeals court allowed them to proceed, at least temporarily. Another hearing is scheduled for November.
Other possible factors in the deaths may emerge in test results over the next few weeks.
Meanwhile, Berman said, the blue whales in the Santa Barbara Channel should soon start their migration toward warmer waters off Costa Rica.
steve.chawkins@latimes.com
Their working theory had been that whales disoriented by the toxin were unable to avoid freighters and tankers inadvertently bearing down on them.
click to enlarge
Photo Gallery"We thought that maybe there was some other reason that these animals were getting hit," Berman said Monday. "Now we can rule out domoic acid."
The acid -- which is produced by a certain type of sea algae -- was not present in tissues extracted from the most recent dead blue whale, a 60-footer that was found in the Santa Barbara Channel and towed to a beach at Point Mugu for scientific examination on Sept. 22.
The freshest of the three whales, it was the only one to yield tissues that were not too decomposed for laboratory analysis.
In 1998, domoic acid was pinpointed as a poison that attacked the brains of dolphins and sea lions off the Central Coast, causing them to lose control of their movements, struggle for breath and sometimes wash ashore.
But the kind of algae that typically produces domoic acid has not recently been found in significant concentrations in the area, Berman said.
The two whales found in the Santa Barbara Channel had numerous broken bones, supporting the ship-collision theory. Collision is strongly suspected in the death of the third whale, which was found in Long Beach Harbor but towed out to sea before experts could get a detailed look at it.
Berman, a biologist, said a team of marine specialists had "completely ruled out" sonar used in Navy training exercises as a contributing factor in the deaths.
Two of the whales died days before the exercises began off San Clemente Island on Sept. 11, and the whale at Point Mugu had no telltale trauma inside or around the ears, she said.
Certain frequencies of sonar have been linked to whale deaths in the Bahamas and elsewhere. At the request of the Natural Resources Defense Council, the California exercises were halted by a federal judge. On Aug. 31, an appeals court allowed them to proceed, at least temporarily. Another hearing is scheduled for November.
Other possible factors in the deaths may emerge in test results over the next few weeks.
Meanwhile, Berman said, the blue whales in the Santa Barbara Channel should soon start their migration toward warmer waters off Costa Rica.
steve.chawkins@
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Director
www.boycottsuperferry.org
Kaua'i, Hawai'i
Check us out on MySpace, and friend us:
http://www.myspace.com/boycottsuperferry
“In our every deliberation we must consider the impact
of our decisions on the next seven generations.â€
~ From the Great Law of the Iroquois Confederacy
"The time is right to do what's right"--Martin Luther King
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