When Technology Meant to Save a Rare Whale Turns Deadly
Some killer whale conservationists have warned for years that barbed satellite tags used to track the animals could cause infection, leading to illness and possibly death. Now their prediction may have come true.
Officials at the National Oceanic and Atmospheric Administration on Wednesday announced that a 20-year-old male member of the endangered Southern Resident killer whale population died of a fungal infection likely related to tagging.
The whale, known as L95, was found dead last March in Canadian waters, with prongs from a device lodged in his dorsal fin. Researchers tagged him on Feb. 24 off the coast of Washington state, but satellite transmissions stopped three days later, suggesting “premature detachment,” NOAA officials said at the time.
The agency suspended killer whale tagging operations pending a final necropsy and an expert panel report, which were released on Wednesday.
“L95 died of a fungal infection, and this infection may have been introduced at the tag wound,” Richard Merrick, chief scientist at NOAA Fisheries, said on a conference call with reporters.
“NOAA and the biologists who work on these whales are deeply dismayed that one of their tags may have had something to do with the death of this whale,” Merrick said. “There is always risk involved while conducting research with wild animals.”
Merrick said the expert panel had “concluded that a few extenuating factors may have predisposed this whale to a severe fungal infection.”
For one, the “incomplete sterilization” of the tag after it fell into the water during an unsuccessful tagging attempt may have played a role, he said. The biologist who shot the device used alcohol to sterilize the tag but failed to also use bleach, as required by NOAA protocol.
Broken prongs that remained in the whale may also have played a role. “The location of the tag was near significant blood vessels, which may have contributed to the infection,” Merrick said.
Finally, he added, the whale’s health may have been compromised at the time of tagging.
“Because the report is not totally conclusive, we will never know exactly what happened,” Merrick said. “But we take the loss of L95 very seriously.”
NOAA will continue to suspend tagging efforts pending reviews of the practice within the agency and by an independent scientific panel. The International Whaling Commission will also hold a tagging workshop next spring.
Merrick said a permanent ban on invasive orca tagging “is a potential outcome.”
Amy Sloan, deputy chief of NOAA’s Permits and Conservation Division, said the reviews will “look at different mitigation measures that can be improved, such as sterilization in the field, appropriate tagging sites, condition of the animals prior to tagging, tag breakage, and working with the manufacturer to improve tag breakages.”
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Deborah Fauquier, NOAA’s veterinary medical officer, said the tag on L95 was implanted lower and closer to the back of the dorsal fin than usual.
“It happened to be near some larger blood vessels, and the fungus particularly likes to invade vessels,” she said. “Unfortunately, there are blood vessels throughout the dorsal fin, and part of the review is to see if there might be some better locations...with smaller blood vessels.”
NOAA deploys tags to track Southern Resident orcas, which spend much of the year in the Puget Sound area. But complete data on where they go in the open ocean are lacking. The tags are important for determining the full extent of their critical habitat, which is required under the United States Endangered Species Act.
The fish-eating Southern Resident population, now at 82, was listed as endangered under the act in 2005. Eight Southern Residents have been tagged since 2012, seven of them without any problems, according to NOAA.
Two mammal-eating orcas, known as transients, disappeared after being tagged in 2010, and some conservationists have demanded an end to the invasive method.
“I’m disappointed that my government hadn’t listened to me in the past about this issue,” said Ken Balcomb, director of the Center for Whale Research. “They just said, ‘OK,’ and crossed their fingers that something like this wouldn’t happen.”
Balcomb said invasive tagging should end permanently and NOAA should concentrate on salmon recovery programs, including dam removals, which are critical for preventing extinction of the population.
Michael Harris, executive director of the Pacific Coast Whale Watch Association, which also supports a ban, said tagging is unnecessary because whales can be tracked through sightings and underwater hydrophones—which is done in Canada, where orca tagging is prohibited—and by analyzing exposures to pesticides that are used only in certain areas.
“It was clear this was a dangerous methodology, and they were advised by esteemed scientists not to use it, and now you add one more factor: human error,” Harris said.
The NOAA biologist who deployed the dart “made a mistake that killed a 20-year-old male, and in this population we cannot afford to lose any whales.”