Shaking down fishing boats
The orcas will wait all day for a fisher to accumulate a catch of halibut, and then deftly rob them blind. They will relentlessly stalk individual fishing boats, sometimes forcing them back into port.
Most chilling of all, this is new: After decades of relatively peaceful coexistence with cod and halibut fishers off the coast of Alaska, the region’s orcas appear to be turning on them in greater numbers.
“We’ve been chased out of the Bering Sea,” said Paul Clampitt, Washington State-based co-owner of the
Like many boats, the has tried electronic noisemakers to ward off the animals, but the orcas simply got used to them. “It became a dinner bell,” said Clampitt. John McHenry, owner of the described orca pods near Alaska’s Aleutian Islands as being like a “motorcycle gang.”
“You’d see two of them show up, and that’s the end of the trip. Pretty soon all 40 of them would be around you,” he said. A report this week in the
outlined instances of aggressive orcas harassing boats relentlessly — even refusing to leave after a desperate skipper cut the engine and drifted silently for 18 hours.
“It’s gotten completely out of control,” Alaska fisherman Jay Hebert told the paper.
Fishing lines are also being pillaged by sperm whales, the large square-headed whale best known as the white whale in
“Since 1997, reports of depredation have increased dramatically,” noted a report by the Southeast Alaska Sperm Whale Avoidance Project.
A remarkable 2006 video by the Avoidance Project captured one of the 50,000 kg whales delicately shaking fish loose from a line. After a particularly heavy assault by sperm whales, fishers are known to pull up lines in which up to 90 per cent of the catch has disappeared or been mangled.
Some skippers will try to outrun a hovering pod, but the time and fuel needed to dodge a persistent gang of whales can wreak havoc on a trip’s profitability.
“I’ve had the same sperm whale follow me 70 miles,” Michael Offerman with the
told the by email.
While fishing boats all across Alaska have reported harassment by orcas, the worst incidents all seem to be occurring in the Bering Strait, the body of water separating western Alaska from Russia.
In a 2014 study of Alaska fisheries, orcas snatching fish from lines were estimated to cost boats as much as US$500 per day. Compare that to Uruguay, where a 2015 study of boats using similar fishing techniques found that “the presence of killer whales in the fishing ground seems not to affect the catch per unit effort.”
Whale predation on fishing boats is increasing in part due to a rebound of North Pacific whale populations brought about by the 1980s moratorium on commercial whaling.
Up until then, cod and halibut fishers were moving amongst whale populations that had been decimated by whaling fleets — and where survivors had learned to fear the approach of a boat engine.
“When I started fishing in the early 80s, when we saw a whale it was an event,” said Clampitt. “Now, they circle the boat.”
This is not the first time that Alaskan waters have been suddenly thrown into disorder by the changing appetites of killer whales. In the 1990s, researchers found that orca predation was responsible for a sudden collapse in Pacific sea otter populations not seen since the animals were driven to nearextinction by the fur trade.
Orcas have remarkably complex social structures, with regionally distinct languages and hunting strategies. They’re also innovative; orcas have frequently been observed inventing new hunting tactics and then teaching them to others.
In April, orcas off Monterey Bay, Calif., killed four grey whale calves over eight days in what was described as an unprecedented “killing spree” by local media. Biologists attributed the episode to a single nine-member pod of orcas that had simply become unusually skilled at hunting grey whales.
Similarly, harassed Alaska fishers say they are seeing increased numbers of juvenile whales — a possible sign that adult orcas are teaching their young to seek out fishing vessels for their meals.
McHenry describing pulling in lines cleared of fish, only to notice that some fish near the end of the line were merely gnawed.
“That was them teaching the little ones; it’s unfortunate the orcas are putting us out of business, because they’re really a phenomenal mammal,” he said.
The only surefire way to ward off a pod of hungry orcas is pot fishing. Rather than fishing with exposed lines, boats convert to “pots”; essentially giant crab traps that trap fish rather than hook them.