Saturday, 4 February 2012

Tagging of orcas raises concern


Federal biologists plan to tag up to six southern resident orcas next month with tiny satellite devices to discover their range of habitat in winter months.

Surveys have shown the animals can travel as far south as Monterey, Calif., and as far as the north coast of British Columbia during winter.

Researchers will use a cross bow or air gun to shoot the dart tags, which have two barbs about 6 centimeters long. The tags provide information for between 16 and 94 days and usually fall off as the whales swim, National Oceanic and Atmospheric Administration Fisheries Service officials say.

Killer whale experts on San Juan are concerned that the darts could injure the orcas.

Ken Balcomb, senior scientist with the Center for Whale Research, applied for a federal permit in 2008 to tag the Puget Sound orcas because at the time he believed the devices were not harmful. He received federal approval in 2009, but later declined to tag any orcas after following orcas that had been darted by the National Marine Fisheries Service.

Balcomb determined that the tags caused swelling and extruding tissues in certain cases.

Balcomb and other orca advocates have questioned whether the benefits of tagging were worth harming the orcas, whose population now stands at 89.

Officials at The Whale Museum advocated more passive measures to track the whales, such as listening to their distinctive sounds, visual observation, and teaming up with other researchers.

In a comment letter, they said NOAA has spent thousands of dollars on surveys that found the whales in shallow waters of the West Coast, but little has been done to protect them from naval warfare training in the area.

“Therefore, we cannot see a compelling need to use an invasive technique to show similar data trends when the existing data observations were not used, or were not adequate, to take conservation measures that would have prevented potential impact to whales in areas and times of the year when they have been demonstrated to use the area,” they wrote.

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