The death of a massive blue whale off the Mendocino Coast offers a valuable opportunity for whale researchers.
"This is a big deal," said Thor Holmes, curator of the vertebrate museum at Humboldt State University and a member of the California Marine Mammal Stranding Network.
The 72-foot whale died after being struck by a research vessel, believed to be the 78-foot Pacific Star. Its crew is under contract to the National Oceanic and Atmospheric Administration to update maps of the ocean floor. The contractor is based in San Diego while the boat was leased from Washington, said Joe Cordaro, a NOAA biologist.
Crew members reported they were seven miles off the coast of Fort Bragg moving at about 5.5 knots when the ship shuddered, he said. They had not spotted a whale and didn't immediately know what happened. Then a whale surfaced, bleeding profusely, Cordaro said.
A few hours later, a blue whale with huge gashes washed up along the rocky coast just south of Fort Bragg.
Cordaro said it's hard to explain how a ship and whale would collide in the open ocean. But when whales are feeding, breeding or coming up for air, they aren't paying attention to their surroundings, he said.
The death saddened Holmes, but when he heard the carcass was in good shape, he grabbed two biology students from their class on the Arcata campus and headed south to Mendocino County to gather information for the marine network, which is overseen by NOAA's National Marine Fisheries Service.
Finding a whale carcass in good condition is rare, he said. Normally, whales die, sink and do not resurface until they're bloated and decomposing, Holmes said.
He believes that marine biologists and museum curators around the country are wishing they had a chance to examine the whale.
"This is gloriously fresh, speaking as a dissector," Holmes said.
He and the students took advantage of low tides Tuesday evening to examine the carcass, which had been rolling in the waves along a rocky, precarious stretch of the Mendocino Coast but was briefly on solid ground.
After climbing down a 30-foot bluff, they collected tissue samples, confirmed the animal was an adult blue whale and determined it was female and about 72 feet long. He estimated the whale weighed over 50 tons and had, at some point, given birth.
Blue whales can grow to 90 feet, but none that size have been seen for many years, said Dawn Goley, director of the university's marine mammal research program.
"Obviously, most of those were hunted," she said.
Typical adult blue whales now range between from 70 feet to 80 feet in length, Goley said.
Holmes determined that the whale had been very healthy and had died from two deep gashes on the back, likely inflicted by a ship's propeller. The cuts penetrated 9 inches of blubber, then muscle, he said. There also were bone fragments.
Based on the extent of the injuries, he believes the whale was dead when it washed up along the coast.
"The size of the injury and the depth of the injury would have caused it to bleed out very quickly," Holmes said.
The tissue samples collected from the whale will be examined for a number of things, including contaminants, which could indicate where the whale has been, Goley said. The whale likely belonged to a population that is commonly found off the coasts of Mexico and California, she said.