A rarely seen Baird’s beaked whale turned up on a beach in the Point Reyes National Seashore this week, a possible victim of a strike by a ship.
Scientists plan to perform a follow-up evaluation of the cetacean’s carcass Thursday to determine whether any vertebrae were fractured. Specialists will also determine the sex of the 35-foot animal, which feeds about 20 miles off the Marin coast.
This is the first Baird’s beaked whale the Marine Mammal Center, a clinic for injured animals, has responded to in its 41-year history. National Marine Fisheries Service historical records for the West Coast region show less than a dozen of the species have ever washed up in California, Oregon and Washington.
“Beaked whales are a very interesting family of toothed whales that mostly live off the continental shelf edge, foraging in deep canyons to feed on squid,” said Padraig Duignan, chief pathologist at the mammal center, which is in the Marin Headlands. “The opportunity to perform a necropsy on such a unique animal that we rarely have the opportunity to examine will help contribute to our baseline data on the species.”
On Monday, a team of 11 scientists from the mammal center, the California Academy of Sciences and the Point Reyes National Seashore arrived at North Beach to perform a necropsy on the whale.
Early in the necropsy, scientists found extensive hemorrhaging near the vertebrae on the left side of the decomposing carcass. They also noted the animal’s fluke had been severed by a sharp object like a propeller, evidence of a vessel strike. But a final determination of the cause of death is pending.
“Was it killed by a ship strike or was it already dead and then hit? It’s not known,” said Giancarlo Rulli, mammal center spokesman. “They feed in deep waters off the continental shelf. They are not near the surface like other whales.”
Busy shipping lanes off the Marin coast were adjusted to protect whales from being hit by ships in 2013 when the International Maritime Organization approved vessel lane changes on approaches to San Francisco Bay.
Under that new plan, the northern shipping lane, which runs along the Marin coast, was narrowed to 3 nautical miles wide, sweeping past the Point Reyes peninsula.
On Thursday, researchers with the California Academy of Sciences will collect samples, including the whale’s skull, for further study and documentation. The academy last collected a skull of a Baird’s beaked whale in 1925.
The whale is a member of a deep water species found in groups ranging from six to 30 animals. They are the largest of the beaked whale family and frequent deep channels off the continental shelf in the North Pacific.
The cetaceans are often recognized by their slender cigar-shaped body and a distinct protruding lower jaw. Adults can grow up to 40 feet in length and weigh up to 25,000 pounds.
Even though they have teeth, the whales don’t normally use them for feeding and instead feed on squid, herring, mackerel and other deep-sea fish by sucking in the prey.
“It’s rare to see them wash ashore like this and it presents a research opportunity,” Rulli said. —— (c)2016 The Marin Independent Journal (Novato, Calif.) Visit The Marin Independent Journal (Novato, Calif.) at www.marinij.com Distributed by Tribune Content Agency, LLC. AMX-2016-08-31T00:01:00-04:00
