Two newly identified types of killer whales that hunt prey off of Antarctic sea ice risk losing food sources to global warming and melting, according to a new study on the whales' movement patterns.
The study reveals that killer whales that feed primarily on fish that congregate under ice shelves are more or less "homebodies," sticking close to the ice, whereas seal-eating killer whales wander wide and seemingly aimlessly.
The differences in movement patterns likely correlate to differences in the whales' foraging strategies and how they interact with their prey, according to the study.
For example, fish-eating whales can stay local because the main anti-predator strategy of fish is to bunch up into schools, often under the ice shelves, according to researchers. On the other hand, the seal-eating whales chase prey with a wider range, as seals wash off of ice floes and travel farther.
Both types of killer whales tracked are heavily dependent on ice cover, according to Robert Pitman, a study co-author and marine biologist with the National Oceanic and Atmospheric Administration in La Jolla, California.
"If there are changes in the amount of ice cover [in the Antarctic] then it means there are going to be changes in the amount of habitat that [the whales] have available to them," Pitman said. "And we're not sure how adaptable they are to living in a different kind of habitat."
The new research, published online this month in the journal Polar Biology, highlights the need to unravel the whale's basic biology, noted Pitman.
The research was supported by a grant from the National Geographic Society (which owns National Geographic News).
New Killer Whale Species?
Pitman and his colleagues have spent nearly ten years compiling evidence to show that three species of killer whales, not one, ply the icy Antarctic waters.
To date, the researchers have identified three "types" of killer whales, each with distinct looks, habits, and diets, and perhaps even unique genes.
One type swims under the cracked ice and eats fish and another feeds on seals and other mammals, such as penguins, from ice floes. The third, a more transient and more studied species, swims in the open ocean and preys primarily on minke whales, which are a small filter-feeding species of marine mammal.
Until the 1970s, Pitman noted, all killer whales, also known as orcas, were considered one species that occurred around the world from the Antarctic to the Arctic and ate anything they could find.
The picture changed when researchers identified three types of killer whales in the North Pacific.
The three types do not interbreed. "In fact, they completely avoid each other," said Pitman, whose studies of Antarctic killer whales are revealing patterns similar to those in the North Pacific.
While scientists are hesitant to call the whale types different species because their differences could be culturally enforced, the whales are "clearly on a trajectory to become separate species," Pitman said.
He noted that their distinct food and habitat preferences, size differences, and perhaps even different vocalizations are all barriers to reproduction.
"At some point, they won't be able to interbreed even if they wanted to," Pitman said.
This May, Pitman co-authored a paper in the journal Biology Letters that found genetic differences that are consistent with reproductive isolation among the three types of Antarctic killer whales.
John Ford is a killer whale expert with Fisheries and Oceans Canada's Pacific Biological Station in Nanaimo, British Columbia.
He said the Antarctic studies fit with the global picture that killer whales represent a complex of populations that function as different species even though they are not yet scientifically described as such.
Ford added that the addition of the satellite tagging technology that Pitman used on his most recent study of killer whales will help "focus our conservation efforts for particular populations that might be in trouble."
maandag 4 augustus 2008
Carcass of baby orca found off San Juan Island
A dead orca calf was recovered from a beach on Henry Island's Open Bay, Saturday, by the San Juan County Marine Mammal Stranding Network.
The calf's carcass was initially sighted and photographed by a part-time resident of Henry Island during low tide the morning of July 26. The Stranding Network reported it did not get the information and pictures until several days later, so when the carcass was finally recovered, it was in a state of advanced decomposition.
It is believed the calf was born prematurely. Cause of death, as well as whether it was a member of a resident or transient pod, is expected to be determined in a necropsy being conducted by Dr. Joe Gaydos, the Stranding Network’s veterinarian and regional director of the SeaDoc Society.
“A newborn killer whale calf is usually 7 to 8 feet long and 300-400 pounds,” Stranding Network Coordinator Amy Traxler said in a press release.
“This carcass was approximately 5 feet long with an estimated weight of 70-80 pounds, so it’s likely this calf was aborted.” The placenta was lying next to the calf when originally discovered, she said.
Gaydos expected to collect tissue samples during the necropsy to determine the whale's parentage.
“If we recover viable skin and blubber, which is not always possible from a decomposed carcass, we might be able to determine if the calf is a member of the Southern resident community and possibly even narrow down the pod of origin,” Traxler said.
Fresh tissue samples also would contain information on contaminant levels and possibly provide a cause for the calf’s abortion.
It’s very rare to recover a body of a stranded killer whale. A recent paper Gaydos presented to the International Whaling Commission suggests that an average of seven killer-whale carcasses are found around the world annually, making every killer whale stranding a rare opportunity to learn more about the biology and diseases of this species.
In May 2002, L-60’s carcass was found on the outer coast of Washington. In January 2002, the body of a female transient whale was recovered by Dungeness Spit. The body of J-18 washed up by Tsawwassen, B.C. in March 2000. The body of L-51 was found in September 1999 near Victoria, B.C.
All of these carcasses were fresh, permitting scientists to learn more about the diseases of killer whales and which diseases might have an impact on the overall health of the population. Fresh necropsy samples also have helped scientists understand how contaminants impact killer whales.
The San Juan County Marine Mammal Stranding Network is one of many science and education programs at The Whale Museum. If you encounter a stranded marine mammal in San Juan County, alive or dead, call (800) 562-8832 and leave a message with your name, phone number, location, and other pertinent details of the stranding.
The calf's carcass was initially sighted and photographed by a part-time resident of Henry Island during low tide the morning of July 26. The Stranding Network reported it did not get the information and pictures until several days later, so when the carcass was finally recovered, it was in a state of advanced decomposition.
It is believed the calf was born prematurely. Cause of death, as well as whether it was a member of a resident or transient pod, is expected to be determined in a necropsy being conducted by Dr. Joe Gaydos, the Stranding Network’s veterinarian and regional director of the SeaDoc Society.
“A newborn killer whale calf is usually 7 to 8 feet long and 300-400 pounds,” Stranding Network Coordinator Amy Traxler said in a press release.
“This carcass was approximately 5 feet long with an estimated weight of 70-80 pounds, so it’s likely this calf was aborted.” The placenta was lying next to the calf when originally discovered, she said.
Gaydos expected to collect tissue samples during the necropsy to determine the whale's parentage.
“If we recover viable skin and blubber, which is not always possible from a decomposed carcass, we might be able to determine if the calf is a member of the Southern resident community and possibly even narrow down the pod of origin,” Traxler said.
Fresh tissue samples also would contain information on contaminant levels and possibly provide a cause for the calf’s abortion.
It’s very rare to recover a body of a stranded killer whale. A recent paper Gaydos presented to the International Whaling Commission suggests that an average of seven killer-whale carcasses are found around the world annually, making every killer whale stranding a rare opportunity to learn more about the biology and diseases of this species.
In May 2002, L-60’s carcass was found on the outer coast of Washington. In January 2002, the body of a female transient whale was recovered by Dungeness Spit. The body of J-18 washed up by Tsawwassen, B.C. in March 2000. The body of L-51 was found in September 1999 near Victoria, B.C.
All of these carcasses were fresh, permitting scientists to learn more about the diseases of killer whales and which diseases might have an impact on the overall health of the population. Fresh necropsy samples also have helped scientists understand how contaminants impact killer whales.
The San Juan County Marine Mammal Stranding Network is one of many science and education programs at The Whale Museum. If you encounter a stranded marine mammal in San Juan County, alive or dead, call (800) 562-8832 and leave a message with your name, phone number, location, and other pertinent details of the stranding.
K-7, oldest of Southern resident orcas, believed dead
K-7, the oldest orca in the Southern resident pods, is believed dead. She is believed to have been 98 years old and was the matriarch of a line that extended five generations.
The whale, also known as Lummi, was last seen Dec. 23 and has not been seen since K pod returned in spring, according to the Center for Whale Research on San Juan Island. All other K pod whales are accounted for, including K-42, a calf born in June.
The Center for Whale Research, which has monitored the local orca population since 1976, puts the whale population at 88. That's 26 in J pod, 19 in K pod and 43 in L. Research assistant Courtney Smith said the estimated population of L pod is "soft" because L pod has spent most of the season along the west coast of Vancouver Island. "We haven't accurately identified everyone in L pod yet," she said.
As for K-7, "(Researchers) have seen everyone else in K pod except K-7. It's safe to say she's gone," Smith said.
K-7's last known sighting was in Puget Sound on Dec. 23 by Brad Hanson of the Northwest Fisheries Science Center.
K-7, believed born in 1910, was an important symbol. When she was born — to parents undoubtedly born in the 1800s — the local orca population was possibly over 120. In her lifetime, she survived bullets from fishermen that saw orcas as competition for salmon. She survived the marine park era, in which 50 whales were captured or died during capture. She survived despite depleted salmon stocks and increased marine pollution.
The population rebounded from 71 in 1973 to 99 in 1995, then plummeted to 79 six years later. The population rebounded to 80 in 2002, 83 in 2003, 85 in 2004 and 89 in 2005, but has seesawed around 88 since then. The local pods were declared endangered by the U.S. and Canada by 2005 and the National Oceanographic and Atmospheric Administration has been patrolling the area to enforce rules requiring boats to maintain a distance of 100 yards from the whales.
The Center for Whale Research says the whales' biggest threats are pollution in Puget Sound and declines in salmon. The center says the Navy may also share the blame.
"The whale population decline is coincident with the deployment of (Destroyer Squadron) 9 to Everett in 1995,” the center's Web site states. "The destroyer squadron's exercise area is nominally off the Olympic Peninsula but has included Strait of Juan de Fuca and Haro Strait.”
The whales are called Southern residents because they spend a lot of the year in this region. J is here much of the year, while K and L travel as far as California but return in the summer.
When the pods return to the San Juan Islands in early summer, the Center for Whale Research gets their first good look at who is present, including any new calves, as well as who may not have made it through the winter.
“These orcas are icons and indicators of the quality of Puget Sound and coastal waters," center director Ken Balcomb said in an earlier interview. "How they fare in coming years will tell us a lot about our own fate.”
With K-42's death, the oldest Southern resident orca is J-2, also known as Granny, believed born in 1911. The matriarch of L pod is L-25, also known as Ocean Sun, born in 1928.
K-42 descendants include a daughter, K-11, believed born in 1933; a granddaughter, K-13; four great-grandchildren, K-20, K-25, K-27 and K-34; and a great-great-grandchild, K-38.
K-38 is the offspring of K-20.
The whale, also known as Lummi, was last seen Dec. 23 and has not been seen since K pod returned in spring, according to the Center for Whale Research on San Juan Island. All other K pod whales are accounted for, including K-42, a calf born in June.
The Center for Whale Research, which has monitored the local orca population since 1976, puts the whale population at 88. That's 26 in J pod, 19 in K pod and 43 in L. Research assistant Courtney Smith said the estimated population of L pod is "soft" because L pod has spent most of the season along the west coast of Vancouver Island. "We haven't accurately identified everyone in L pod yet," she said.
As for K-7, "(Researchers) have seen everyone else in K pod except K-7. It's safe to say she's gone," Smith said.
K-7's last known sighting was in Puget Sound on Dec. 23 by Brad Hanson of the Northwest Fisheries Science Center.
K-7, believed born in 1910, was an important symbol. When she was born — to parents undoubtedly born in the 1800s — the local orca population was possibly over 120. In her lifetime, she survived bullets from fishermen that saw orcas as competition for salmon. She survived the marine park era, in which 50 whales were captured or died during capture. She survived despite depleted salmon stocks and increased marine pollution.
The population rebounded from 71 in 1973 to 99 in 1995, then plummeted to 79 six years later. The population rebounded to 80 in 2002, 83 in 2003, 85 in 2004 and 89 in 2005, but has seesawed around 88 since then. The local pods were declared endangered by the U.S. and Canada by 2005 and the National Oceanographic and Atmospheric Administration has been patrolling the area to enforce rules requiring boats to maintain a distance of 100 yards from the whales.
The Center for Whale Research says the whales' biggest threats are pollution in Puget Sound and declines in salmon. The center says the Navy may also share the blame.
"The whale population decline is coincident with the deployment of (Destroyer Squadron) 9 to Everett in 1995,” the center's Web site states. "The destroyer squadron's exercise area is nominally off the Olympic Peninsula but has included Strait of Juan de Fuca and Haro Strait.”
The whales are called Southern residents because they spend a lot of the year in this region. J is here much of the year, while K and L travel as far as California but return in the summer.
When the pods return to the San Juan Islands in early summer, the Center for Whale Research gets their first good look at who is present, including any new calves, as well as who may not have made it through the winter.
“These orcas are icons and indicators of the quality of Puget Sound and coastal waters," center director Ken Balcomb said in an earlier interview. "How they fare in coming years will tell us a lot about our own fate.”
With K-42's death, the oldest Southern resident orca is J-2, also known as Granny, believed born in 1911. The matriarch of L pod is L-25, also known as Ocean Sun, born in 1928.
K-42 descendants include a daughter, K-11, believed born in 1933; a granddaughter, K-13; four great-grandchildren, K-20, K-25, K-27 and K-34; and a great-great-grandchild, K-38.
K-38 is the offspring of K-20.
zondag 3 augustus 2008
Group campaigns for return of penned orca
Annual memorial strives for killer whale's release
It was 38 years ago this Friday that life changed forever for the southern resident killer whales.
As members of the three resident orca pods travelled up Puget Sound, explosives were thrown into the water from aircraft and about 100 frantic animals were driven into Penn Cove on Whidbey Island and netted.
At least four whales were killed and about seven others were captured and taken to aquariums.
It was the height of the whale captures between 1965 and 1973, which saw about a dozen whales killed and at least 45 captured from the waters of southern Vancouver Island and Puget Sound.
The population, now listed as endangered with 88 whales in three pods, has never recovered and is now facing the additional threats of pollution and shrinking salmon runs.
The only survivor of the southern resident captures is Lolita, a member of L Pod who, for 38 years, has lived in a cramped tank at Miami Seaquarium.
Each year on Aug. 8, in a grim commemoration at the Captain Whidbey Inn at Penn Cove, the Orca Network holds a ceremony to remember the capture and make yet another plea for Lolita's release.
After an evening of special presentations, there will be a waterside ceremony, said Susan Berta of Orca Network.
"We make a wreath out of cedar and native plants and, at the end of the event, we go and put the wreath in the water," she said.
"Every year we hope it will be the year to welcome home Lolita. We hold on to that."
Earlier this year a group of celebrities became active in trying to get Lolita released, and animal-rights lawyers around Miami are looking for ways to launch a lawsuit.
But Miami Seaquarium has shown no sign of budging, even though Lolita -- now in her early 40's -- is no longer the major star of the shows.
In a statement issued earlier this year, Andrew Hertz, general manager of Miami Seaquarium, said releasing Lolita is not an option and there is no scientific evidence she could survive in the open ocean.
"Lolita will remain at Miami Seaquarium surrounded by people who love and protect her," he said.
Everyone is welcome at the Penn Cove event and the audience includes a core group of people who witnessed the capture, Berta said.
"They feel they need to recognize the horror of it and remember the whales we have lost," Berta said.
For more information visit www.orcanetwork.org.
It was 38 years ago this Friday that life changed forever for the southern resident killer whales.
As members of the three resident orca pods travelled up Puget Sound, explosives were thrown into the water from aircraft and about 100 frantic animals were driven into Penn Cove on Whidbey Island and netted.
At least four whales were killed and about seven others were captured and taken to aquariums.
It was the height of the whale captures between 1965 and 1973, which saw about a dozen whales killed and at least 45 captured from the waters of southern Vancouver Island and Puget Sound.
The population, now listed as endangered with 88 whales in three pods, has never recovered and is now facing the additional threats of pollution and shrinking salmon runs.
The only survivor of the southern resident captures is Lolita, a member of L Pod who, for 38 years, has lived in a cramped tank at Miami Seaquarium.
Each year on Aug. 8, in a grim commemoration at the Captain Whidbey Inn at Penn Cove, the Orca Network holds a ceremony to remember the capture and make yet another plea for Lolita's release.
After an evening of special presentations, there will be a waterside ceremony, said Susan Berta of Orca Network.
"We make a wreath out of cedar and native plants and, at the end of the event, we go and put the wreath in the water," she said.
"Every year we hope it will be the year to welcome home Lolita. We hold on to that."
Earlier this year a group of celebrities became active in trying to get Lolita released, and animal-rights lawyers around Miami are looking for ways to launch a lawsuit.
But Miami Seaquarium has shown no sign of budging, even though Lolita -- now in her early 40's -- is no longer the major star of the shows.
In a statement issued earlier this year, Andrew Hertz, general manager of Miami Seaquarium, said releasing Lolita is not an option and there is no scientific evidence she could survive in the open ocean.
"Lolita will remain at Miami Seaquarium surrounded by people who love and protect her," he said.
Everyone is welcome at the Penn Cove event and the audience includes a core group of people who witnessed the capture, Berta said.
"They feel they need to recognize the horror of it and remember the whales we have lost," Berta said.
For more information visit www.orcanetwork.org.
donderdag 24 juli 2008
Whale Watchers in North Iceland Observe Slaughter
Around 100 tourists on a whale watching tour with Nordur-Sigling from Húsavík on Skjálfandaflói bay in northeast Iceland were in for a shock on Tuesday night when they observed a group of killer whales attack a larger minke whale, slaughter and eat it.
“No one was expecting to observe slaughter but we decided to follow this natural phenomenon because it is very unusual,” Heimir Hardarson, marketing director of Nordur-Sigling, told Morgunbladid, adding that the tourists, who were mostly foreign, had been very taken aback by the spectacle.
Tuesday was likely the first time that pictures have been taken of killer whales attacking a larger mammal in Icelandic waters. Killer whales are on top of the food chain of predators in the ocean and are sometimes called the wolves of the sea.
Killer whales are divided into two groups—which some say are two different species—one of which only feeds on fish and another which hunts mammals of all sizes. Until now, only the first group was believed to live in Icelandic waters.
“It was obviously very organized and not rushed at all,” Hardarson described. “They acted like those who are in power and the calves jumped around and played in the blood.”
Hardarson and his associates counted between 20 and 30 killer whales that participated in the attack. They were very coordinated; they had surrounded the minke whale and then took charge in turn.
Hardarson said the minke whale had been terrified. “It was so confused that it swam into the boat two times and one time it looked as if it was going to hide underneath it.”
The minke whale died after a heroic fight, Hardarson said, and then there was a great feast for the killer whales which shared their catch with every member of the group.
Killer whales are known to have killed great white sharks and blue whales, but they are not known to have attacked people.
“No one was expecting to observe slaughter but we decided to follow this natural phenomenon because it is very unusual,” Heimir Hardarson, marketing director of Nordur-Sigling, told Morgunbladid, adding that the tourists, who were mostly foreign, had been very taken aback by the spectacle.
Tuesday was likely the first time that pictures have been taken of killer whales attacking a larger mammal in Icelandic waters. Killer whales are on top of the food chain of predators in the ocean and are sometimes called the wolves of the sea.
Killer whales are divided into two groups—which some say are two different species—one of which only feeds on fish and another which hunts mammals of all sizes. Until now, only the first group was believed to live in Icelandic waters.
“It was obviously very organized and not rushed at all,” Hardarson described. “They acted like those who are in power and the calves jumped around and played in the blood.”
Hardarson and his associates counted between 20 and 30 killer whales that participated in the attack. They were very coordinated; they had surrounded the minke whale and then took charge in turn.
Hardarson said the minke whale had been terrified. “It was so confused that it swam into the boat two times and one time it looked as if it was going to hide underneath it.”
The minke whale died after a heroic fight, Hardarson said, and then there was a great feast for the killer whales which shared their catch with every member of the group.
Killer whales are known to have killed great white sharks and blue whales, but they are not known to have attacked people.
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