Tag Archives: Cascadia Research Collective

Unique ‘tropical oceanic’ orcas still traveling west

UPDATE, Dec. 7

I have received word from researcher Robin Baird that the last remaining transmitter tracking the “tropical oceanic” killer whales stopped working on Nov. 26, six days after this report. The transmitter presumably fell off. I’ve attached a map provided by Robin in the comments section at the bottom of this page. It shows the whales’ last 10 days of travel. They kept on moving southwest.
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KW 2013NOV1-19_WM

“Tropical oceanic” killer whales, which were tagged near Hawaii and tracked by satellite, have now moved about 860 miles west.

As of yesterday, they were approaching Johnston Atoll, seen just to the left of their last known location shown on the map above, according to Robin Baird of Cascadia Research Collective, based in Olympia.

Initially, three orcas were tagged in this first effort to track the unique breed of killer whale, which travels in the open ocean. For a description of tropical oceanic killer whales, including their varying diet, review the entry in Water Ways on Nov. 12.

Two of the three transmitters attached to the whales have stopped working, presumably because the barbed tags fell off the animals. One transmitter, attached to an adult female, continues to send out information about the location of the four whales, assuming they have stayed together.

After traveling northwest through the Hawaiian Islands, the whales have taken a pretty direct path toward Johnston Atoll, slowing down a few times along the way. It will be interesting to see where they go next.

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Gray whale was eating trash before he died

Plastic bags, small towels, surgical gloves, sweatpants and a golf ball.

These and many other small pieces of plastic and assorted debris were found in the stomach of a dead gray whale that washed up last week on a West Seattle beach.

Despite those findings, the man-made debris probably did not cause the death of the whale, which was not as emaciated as three other gray whales that have died recently in Puget Sound, according to John Calambokidis of Cascadia Research Collective.

Still, the items are an unprecedented amount of junk to find in the stomach of a gray whale in Washington state, said Calambokidis, who participated in the necropsy over the weekend. John said he has never seen this number of foreign objects in a gray whale, and Cascadia’s records cover nearly 200 such whales examined over many years.
Continue reading →

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Navy research considers effects of sonar on whales

The U.S. Navy is collaborating with private and governmental researchers in an effort to determine how sonar affects marine mammals.

Tracey Moriarty, chief of the Naval Operations Environmental Readiness Division, describes three recent field studies in a piece published Monday on the Navy News Web site.

One project, based in the Bahamas, involved tracking marine mammals — notably beaked whales — during battle group exercises. Before the exercises started, researchers were able to attach radio and acoustic “tags” to three Blaineville’s beaked whales, a Cuvier’s beaked whale and five sperm whales.

Beaked whales are believed to be especially sensitive to sonar. It was in the Bahamas that six beaked whales were found dead on the beach within 24 hours of a Navy exercise.

“The mere presence of these species on a Navy range is counterintuitive to the perception of beaked whale reactions to sonar,” the Navy’s David Moretti was quoted as saying. “Given that this is an active Navy range where sonar is used, you wouldn’t anticipate this species to be present in this particular location if you believed the popular press.”

Moretti is the principal investigator for the Marine Mammal Monitoring Program at the Naval Undersea Warfare Center in Rhode Island.

“The animals are moving in and out of here,” said Diane Claridge, director of the Bahamas Marine Mammal Research Organization, “and one of the things I’m interested in is whether or not that movement is related to the activities taking place such as the SCC (the Navy exercise).”

The working hypothesis is that the animals move off the training range during sonar exercises and then come back when the exercises are over, but researchers can’t be sure the returning animals are the same.

“I think the most important thing is that it’s still very early,” John Durban of the National Marine Fisheries Service said in Moriarty’s report. “Like any study, it’s tempting to want results straight away, but often the key results are only obtained from continued long-term monitoring of abundance and movement patterns.”

A similar experiment in California was conducted with the assistance of Greg Schorr and Erin Falcone of Cascadia Research Collective, based in Olympia. By the way, Cascadia’s Robin Baird collaborated on a study published in June (PDF 832 kb) about the likelihood of beaked whales getting “the bends” when startled by sonar.

The third experiment, in the Mediterranean Sea, looked at the responses of whales to sound in an area where whales were unlikely to have been exposed to sonar in the past.

I’m looking forward to conclusions from all three studies, which are expected to be described in upcoming reports.

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Gray whales were probably killed by a ship, researchers say

Two gray whales found dead this week in Northern Puget Sound probably died after they were struck by a large ship, according to a summary report by John Calambokidis and Jessie Huggins of Cascadia Research Collective in Olympia.

The report was written following a necropsy of the two whales.

Although there have been lots of gray whale sightings around Whidbey Island this spring, so far we have seen fewer deaths than average. These are the third and fourth gray whales found dead this year in Washington state.

What is odd about these two deaths is that they appear to be unrelated, and both animals appeared to be relatively healthy at the time of their death, according to the report, which includes photos.

“Both showed signs of traumatic injuries, although we are awaiting further tests to be sure these were the ultimate cause of death,” the report states. “Whales are known to die from ship and boat strikes and these injuries can sometimes be hard to spot especially once decomposition has set in.”

Personally, I can’t remember any deaths like this in recent years, and to have two dead whales from traumatic injuries this close together seems especially odd.

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