A team in Coffman Cove helped set free two killer whales that had been trapped in Barnes Lake on northeast Prince of Wales Island since mid-August for six weeks, according to the National Oceanic and Atmospheric Administration.
The orcas presumably stranded themselves by chasing prey into the lake during a high-tide cycle. Transient, or Bigg’s, killer whales are a genetically and culturally distinct population of orcas that live in the Pacific Northwest and feed primarily on marine mammals, according to NOAA.
Barnes Lake has two entrances from salt water that a whale could pass through during a very high tide; the north and south entrances become whitewater rapids, shallows or dry land at low tide. Experts and community members during a high-tide cycle last week used multiple techniques to encourage the orcas to exit through a narrow channel at the south end of the lake when the tide allowed a brief opportunity on Sept. 29.
The 42-year-old male and 16-year-old male orcas — well known to researchers — were not the first whales to be trapped in the lake. In 1994, a pod of nine offshore killer whales, a different ecotype of orcas, spent about six or seven weeks in the lake before whale biologist David Bain led efforts to push them back into the ocean. Two of those nine orcas died before the others were freed from the lake.
Bain, who is the chief scientist for the Orca Conservancy, returned to Barnes Lake last month to lend his experience to the latest effort.
Mandy Keogh, Alaska marine mammal stranding coordinator for NOAA, said Coffman Cove community members reported sightings of the two killer whales in the lake as early as Aug. 17.
“These whales were out of habitat and they needed intervention to get back to their natural environment,” Keogh said. “So, in that case, it becomes a stranding.”
One high-tide cycle in August would have allowed the killer whales to swim through the channel on their own, but they didn’t find their way out during those high tides, Keogh said. Experts began hatching a plan for the next high-tide cycle from Sept. 28 to Oct. 2.
“That gave us time to bring in a team,” Keogh said.
Keogh said she worked primarily with Jared Tower, who is a killer whale research technician with the Department of Fisheries and Oceans Canada, Chloe Kotik, a Ph.D. student with the University of Alaska Fairbanks whose research focuses on transient killer whales, and David Bain.
Tower brought technology that allowed the team to play calls recorded of other whales, according to Keogh.
The team also used a hukilau, a weighted fishing net that’s used in Hawaii, and oikomi pipes, which are a traditional sonic deterrent used in Japan and made by banging hammers against hollow pipes set into the ocean off the side of boats, Keogh explained.
Using skiffs, the team employed all three tactics to corral the killer whales in the north channel of Barnes Lake.
Residents of Coffman Cove did some heavy lifting throughout the rescue, Keogh said. “I think they had about 15 boats and over 30 community members who came out during the two-day response and spent their time and boats on the water and kind of shared their knowledge with us.”
The team on Sept. 28 focused on the north channel. In 1994, boats with oikomi pipes successfully pushed offshore killer whales through the north channel, though the tide was higher, the whales were smaller and the kelp bed had deteriorated more into the winter, according to Bain.
“We knew that the kelp bed in the north channel was potentially a psychological barrier,” Keogh said. “We thought if we had the tides timed right, the kelp would drop down enough for the whales to get over and out.”
However, the orcas didn’t make it through the north channel on Sept. 28.
“It looked like the kelp was actually kind of physically blocking them,” Keogh said. “So even though we had a really high tide, the whales were just too large to get past the kelp bed without getting like kelp wrapped around themselves. So, they backed out and got back into the lake.”
Bain, the killer whale scientist that headed the 1994 rescue, said the older male is about 25 feet long, while the subadult male is about 21 feet long.
On the second day, the team “took a different approach” involving two teams, Keogh said.
“We had one team of folks that were on the north entrance working to clear the kelp out,” in case the whales had to pass that way, “and then the second team focused on trying to encourage the whales out of the lake from the south entrance,” she said.
It was an even higher tide on Sept. 29, 18 feet, which “was really the best chance we had on that south entrance,” she said.
Using playback audio of whale calls, Towers drew the two orcas toward the south channel. Bain said that “playback kind of gave (the whales) the impression that another whale could go through that channel, so they tried to go out that direction and ended up following the boat out.”
The whales swam from the channel into the ocean.
“After they left the lake, we followed them for about two and a half hours, and they made it over 10 miles away by the time that we stopped following them,” Bain said. “We left them in a place called Lincoln Rock.”
The freed orcas visited with a group of humpback whales out at sea, Bain said.
“They basically went east ... they went way over to the far shore and they stopped to visit a group of humpback whales,” he said. “They didn't fight with each other; they just ended up in the same neighborhood.”
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