Bambistew
Well-known member
ANCHORAGE, Alaska (AP) -- Sperm whales have learned to pluck sablefish from fishing lines being hauled from the depths of the Gulf of Alaska, showing a dexterity that belies their enormous size and toothy, underslung jaws.
"They somehow just pick them off like grapes," said Sitka commercial fisherman Dick Curran, who has fished the gulf's deep waters for decades. "I don't know how they do it, and I don't know the depth. ... Sometimes you get the heads back, sometimes you just see lips, and sometimes they're just shredded."
No one knows how the whales have come to target sablefish, also called black cod, whose oily, rich flesh has become a lucrative product in Japanese markets. But a coalition of commercial fishermen and biologists has begun to investigate with about $200,000 from the North Pacific Research Board.
"We don't want the fishermen to have an economic loss. Plus it's a biological loss, because we don't know how many sablefish are being taken," said Sitka-based whale specialist Jan Straley, a lead investigator in the project. "My interest is biological, and I really want to understand what these whales are doing."
What Straley and her partners have found after one season suggests that male sperm whales may patrol the edge of the continental shelf, where the water is 1,200 to 3,000 feet deep.
The whales' behavior off Alaska's coast gives people a chance to study a complex ocean predator that has the largest brain of any animal ever known.
"For sure they know the sound of hydraulics engaging. ... It's like ringing the dinner bell for them," said Linda Behnken, director of the Alaska Longline Fishermen's Association, which is coordinating the study.
"But they've gone one step beyond that. They've learned that the flag and bag (of the buoy) in the water is all part of that dinner bell. Everyone knows whales are smart, and they're proving it."
Federal surveys confirm that sperm whales don't always pluck fish when they're around, Sigler said. When the whales do take fish, the catch rates decrease by 20 percent to 25 percent.
"No one likes to get fewer fish, but take one look at those big whales and you realize you're out of your league," said Sitka longliner Dan Falvey, who, along with Curran, is one of 10 fishermen working with Straley.
"We'll set and there will be no sperm whales around, and we'll be coming out from our anchorage and there'll be two or three sperm whales waiting by the flag," Falvey said. "Sometimes they'll swim by the boat less than 40 or 50 feet away and stick their head out of the water and look at you with their big eyeballs, and just look at what's going on."
Sperm whales are the largest toothed cetaceans, ranging more than 35 tons and 50 feet long. That's longer than a city bus and three times as heavy. Their bodies are about 40 percent head.
Like other great whales, they find prey with their extraordinary hearing, able to perceive their environment with echoed clicks and other sounds. In other areas of the Pacific, sperm whales are known for taking 45-minute dives to gulp giant squid.
To harvest black cod, fishermen sink a 2-mile-long line with baited hooks every 3 to 6 feet. Each end is anchored to the sea floor along the continental slope and buoyed at the surface. After a 8- to 12-hour "soak," fishermen haul the line, sometimes harvesting hundreds of sablefish in a single set.
Over the past few decades, some of the gulf sperm whales apparently realized that fishermen were bringing this deep food source to the surface, and learned to remove a 20- to 30-inch fish from hooks. They also seem to enjoy what fishermen throw overboard after processing the catch.
The whales have yet to get seriously hurt or entangled in the sablefish gear, according to fishery managers and whale biologists. Yet the situation has the potential to put a largely unknown population of legally endangered animals at odds with what has become one of Alaska's most valuable fisheries.
Personally I hope they do away with long line fishing all together. Look what its done for the swordfish in the atlantic... They used to catch 3-500 pounders now they're lucky to catch a 75pounder. Alaska has some of the most screwed up commercial fishing laws. Numberous populations of salmon have almost become extinct and others are on the verge.
I'm cheering for the whales...
"They somehow just pick them off like grapes," said Sitka commercial fisherman Dick Curran, who has fished the gulf's deep waters for decades. "I don't know how they do it, and I don't know the depth. ... Sometimes you get the heads back, sometimes you just see lips, and sometimes they're just shredded."
No one knows how the whales have come to target sablefish, also called black cod, whose oily, rich flesh has become a lucrative product in Japanese markets. But a coalition of commercial fishermen and biologists has begun to investigate with about $200,000 from the North Pacific Research Board.
"We don't want the fishermen to have an economic loss. Plus it's a biological loss, because we don't know how many sablefish are being taken," said Sitka-based whale specialist Jan Straley, a lead investigator in the project. "My interest is biological, and I really want to understand what these whales are doing."
What Straley and her partners have found after one season suggests that male sperm whales may patrol the edge of the continental shelf, where the water is 1,200 to 3,000 feet deep.
The whales' behavior off Alaska's coast gives people a chance to study a complex ocean predator that has the largest brain of any animal ever known.
"For sure they know the sound of hydraulics engaging. ... It's like ringing the dinner bell for them," said Linda Behnken, director of the Alaska Longline Fishermen's Association, which is coordinating the study.
"But they've gone one step beyond that. They've learned that the flag and bag (of the buoy) in the water is all part of that dinner bell. Everyone knows whales are smart, and they're proving it."
Federal surveys confirm that sperm whales don't always pluck fish when they're around, Sigler said. When the whales do take fish, the catch rates decrease by 20 percent to 25 percent.
"No one likes to get fewer fish, but take one look at those big whales and you realize you're out of your league," said Sitka longliner Dan Falvey, who, along with Curran, is one of 10 fishermen working with Straley.
"We'll set and there will be no sperm whales around, and we'll be coming out from our anchorage and there'll be two or three sperm whales waiting by the flag," Falvey said. "Sometimes they'll swim by the boat less than 40 or 50 feet away and stick their head out of the water and look at you with their big eyeballs, and just look at what's going on."
Sperm whales are the largest toothed cetaceans, ranging more than 35 tons and 50 feet long. That's longer than a city bus and three times as heavy. Their bodies are about 40 percent head.
Like other great whales, they find prey with their extraordinary hearing, able to perceive their environment with echoed clicks and other sounds. In other areas of the Pacific, sperm whales are known for taking 45-minute dives to gulp giant squid.
To harvest black cod, fishermen sink a 2-mile-long line with baited hooks every 3 to 6 feet. Each end is anchored to the sea floor along the continental slope and buoyed at the surface. After a 8- to 12-hour "soak," fishermen haul the line, sometimes harvesting hundreds of sablefish in a single set.
Over the past few decades, some of the gulf sperm whales apparently realized that fishermen were bringing this deep food source to the surface, and learned to remove a 20- to 30-inch fish from hooks. They also seem to enjoy what fishermen throw overboard after processing the catch.
The whales have yet to get seriously hurt or entangled in the sablefish gear, according to fishery managers and whale biologists. Yet the situation has the potential to put a largely unknown population of legally endangered animals at odds with what has become one of Alaska's most valuable fisheries.
Personally I hope they do away with long line fishing all together. Look what its done for the swordfish in the atlantic... They used to catch 3-500 pounders now they're lucky to catch a 75pounder. Alaska has some of the most screwed up commercial fishing laws. Numberous populations of salmon have almost become extinct and others are on the verge.
I'm cheering for the whales...
