Dead porpoises pique interest
July 3, 2008 · Updated 2:51 PM
Environmentalists are wondering if dead marine mammals washing up on area beaches were killed by intense, mid-frequency sonar that was projected May 5 by a U.S. Navy destroyer into Haro Strait between San Juan and Vancouver islands.
The sonar waves from the USS Shoup were strong enough to be heard by people on whale watching boats who reported seeing porpoise, orcas and minke whales in the area acting strangely.
This incident comes as the U.S. House of Representatives is discussing a proposal to exempt the Department of Defense from the Marine Mammal Protection Act and Endangered Species Act. Critics argue that it could free the Navy to use sonar more freely, regardless of its effects on whales and porpoises.
Just over a week after the sonar testing in the San Juans, two dead harbor porpoises washed up on Whidbey Island beaches. A dead Dahls porpoise has been reported on Fidalgo Island. And several dead marine mammals have come ashore in the San Juans.
Are these marine incidents related?
Maybe none are, Susan Berta of Orca Network said. But its enough of a coincidence that we have to take a look.
Thursday night, Brad Hanson, a researcher with Northwest Fisheries Center in Seattle, collected the harbor porpoise carcass from the beach at Admiralty Head in Fort Casey State Park. Volunteers with Whidbey Island Marine Mammal Stranding Network had secured the body after collecting data and taking digital photos.
The porpoise had no external signs of injury but was bleeding from the eye and blowhole.
Although eagles had scavenged the animal, Berta said necropsy tests could reveal possible causes of death from pressure trauma to pathology. Theyll be looking for all types internal trauma plus pathogens, bacteria and parasites, she said.
Berta said looking at biological contaminants is important because May 3, a cruise ship discharged 40 tons of raw sewage into Admiralty Inlet about four nautical miles off Whidbey Island.
Cmdr. Karen Sellers, public affairs officer for Navy Region Northwest, did not immediately return phone calls. However, in a statement Sellers stated that neither visual lookouts nor the ships instruments detected the presence of marine mammals in the immediate area. The sonar sweep ended when Canadian authorities reported complaints from small-boat operators.
Berta thinks Seattle researchers will finish testing all the collected dead animals within the month. Another dead harbor porpoise has been reported on West Beach but has not been found. Neither has a dead Dahls porpoise around Fidalgo Island. Berta encourages people to report all marine mammal strandings.
Even decomposed bodies have clues to cause of death, she said.
All washed up
To report any sightings or strandings of dead marine mammals, call Orca Network, 678-3451, or Beach Watchers, 679-7391. For sightings in the San Juans, call the Whale Museum in Friday Harbor, 1-800-562-8832. For Washingtons northwest region, call National Marine Fisheries Service, (206) 526-6733.