The carcasses of two endangered whales, possibly a mother and her calf, dislodged from the hull of an Australian Navy destroyer as it came in to berth at a base in San Diego on Saturday.
The HMAS Sydney warship — a 146-metre-long vessel with a hull that extends more than seven metres below the waterline and a top speed of some 28 knots — has been conducting joint exercises with the U.S. Navy in the waters off California since early April.
At about 9:45AM on May 8, as the ship was pulling into a pier at Naval Base San Diego, two dead fin whales came loose from the underside of the ship.
One was 65 feet long and the other was about 25 feet long, a U.S. Navy spokesperson told 10 News San Diego. They may have been mother and calf, according to John Calambokidis, research biologist at the Cascadia Research Collective in Washington who’s been studying whales and ship strikes for decades.
“It’s sad, but it’s also not surprising,” Calambokidis told 10 News San Diego. “In the vast majority of cases I’m familiar with, the ship is unaware of having struck the whale.”
The larger of the two was towed out to sea on Tuesday afternoon to be sunk.
Calambokidis said that the species of whale in this case – fin whales, the second-largest animal in the world behind the blue whale – is particularly susceptible to ship strikes due to its large size and its tendency to breathe, rest and sometimes feed near the surface. Fin whales are listed as “endangered” under the Endangered Species Act, and the National Oceanic and Atmospheric Administration (NOAA) lists “vessel strikes” as the species’ biggest threat.
There are currently about 3,200 of the animals living in the waters off of California, Oregon and Washington, but Calambokidis said that as many as 50 whale strikes occur off the coast of California alone each year.
Following the discovery of the two dead whales, a spokesperson for the Australian Department of Defence said that Australian and U.S. navies were cooperating with local marine authorities and other agencies to review the incident.
“The US Navy and the Royal Australian Navy are cooperating with the NOAA [National Oceanic and Atmospheric Administration] Fisheries and other agencies to review the incident,” the spokesperson said in a statement to AAP.
“The Navy takes marine mammal safety seriously and is disheartened this incident occurred.”
Follow Gavin on Twitter.