Necropsy Rules Out Domoic Acid Poisoning
Third Blue Whale Death Ruled Unusual Mortality Event
A necropsy conducted on a blue whale carcass at Pt. Mugu showed the animal didn’t have any detectable levels of domoic acid in its system, contrary to scientific speculation last week.
The blue whale – the third killed by a ship strike off the Southern California coast in September – was first spotted floating in the Santa Barbara Channel off of Platform Gail on Thursday, September 20. A storm then moved the body to an eddy, where it circled between Platform Gail and Platform Grace. The whale had not been dead long, scientists determined, because the skin was still intact and blue, and there were no major external injuries.
Santa Barbara Museum of Natural History’s assistant curator of vertebrate zoology, Michelle Berman, called the National Oceanic and Atmospheric Administration (NOAA) and asked that the animal be brought in, because fresher testing means better results, explained museum spokesperson Easter Moorman. The whale was taken to Pt. Mugu, where a day-long necropsy was conducted on Saturday, September 22. It was determined the whale had a smashed cranium, broken ribs, and a severed backbone. Additonally, no sonar activity was linked to the death.
At the time, scientists believed domoic poisoning could’ve been a contributing factor to the whale’s death. The neurotoxin exists in algae and if eaten could have hindered the whale’s ability to quickly get out of the way of, or see, an oncoming ship. The three blue whale deaths have been identified by the NOAA as unusual mortality events (UMEs).
The first whale, a sub-adult male estimated to be between 65 and 70 feet long, came into Long Beach Harbor on the bow of a ship on Saturday, September 8, and was ruled dead from a ship strike, though no necropsy was performed. The animal was later towed out to sea. Rumors that the whale was floating not far off the shore of San Clemente and Ensenada have not been verified.
A necropsy was done on the second dead whale, which washed ashore on Hobson Beach in Ventura County. The 72-foot long female whale, who also died from a ship strike, was eventually cut up and buried on Faria Beach about two miles away.
NOAA is asking the public to notify the Marine Mammal Stranding Network if they spot any floating whales. Call the Santa Barbara Museum of Natural History at 682-4711 ext. 157.
