Apologies to my readers for a lack of updates this last week. I'm driving my mother to Burleson, Texas and she is old, deaf, and mobility impaired. So it's been work. I simply haven't had the time to update here, and when I have had the time, haven't had the energy.
I was planning to get all caught up today...stopped early on purpose just to do so..but the hotel was the hotel room from hell, which I didn't realize until we'd already got unpacked. Despite the problems - no TV, no internet, running toilet, loud refrigerator (neither of which my mom could hear, of course) my mom didn't want to move.
Finally, at 7.17 pm Central time I'm able to access the internet, but I'm too mentally exhausted to do anything except complain about how exhausted I am.
So this blog will return to form - and have new features - on this comng Sunday, when we will have arrived in Burleson and I can work all day long.
Thanks for understanding!
Wednesday, September 29, 2010
Saturday, September 25, 2010
Screams of dying whales haunt Far North rescue
The Northern Advocate: Screams of dying whales haunt Far North rescue
Rescuers struggled in soft sand and against the ferocious sting of windblown sand to reach whales beached in a mass stranding on one of Northland's most remote beaches.
Joyce Munns, manager of nearby Waitiki Landing Holiday Park, said she will never forget the sound of the dying whales' "high-pitched screams".
Yesterday's stranding at Spirits Bay, 90km north of Kaitaia and between Cape Reinga and North Cape, was even bigger than last month's at Karikari Beach. Again, it involved pilot whales.
Atrocious weather conditions combined with crashing surf meant rescuers faced a hard job to save the whales from drowning or being dashed against rocks. Some of the whales had to be euthanised because of their injuries.
The remaining whales were due to be transported by truck to Rarawa Beach this morning in a desperate attempt to save their lives.
Volunteers from Project Jonah, Far North Whale Rescue, and other DoC offices in Northland and Auckland, along with members of the local Te Hapua community put in a long night to help keep the surviving whales alive.
"They will be lifted up with big nets on to the back of trucks with straw or hay loaded on them," Project Jonah chairman Mark Simpson said.
It was not clear how many trucks would be involved in the move but more help from the public would be needed throughout the day.
Advertisement"More whales are still coming in. Pilot whales have very strong social bonds and they try to help each other so more keep getting stuck," Mr Simpson said last night.
Ms Munns said she and other helpers felt useless against the furious weather conditions and the inevitability that the whales they could see "bobbing around" beyond the surfline would also strand. Many did.
About 6pm, Ms Munns went home, unable to stay with other rescuers for the long night time vigil of trying to shift the whales above the surf line and keeping them wet.
The alarm was raised at 11.30am when 32 pilot whales were reported stranded. By 2pm, 74 whales were stranded along a 2km stretch of beach. Of those, 49 were still alive. During the afternoon only nine had been refloated.
Kaitaia area manager Jonathan Maxwell said considerable effort and manpower will be required to save so many whales, with up to five people required per whale. Anyone who can help is urged to report to Spirits Bay-Kapowairua campground, with wetsuit, warm clothing and wet weather gear, he said.
Human safety was the number one priority, so careful planning and co-ordination were crucial, Mr Maxwell said.
The stranding at Karikari Beach, just a month ago on August 20, involved 58 pilot whales ranging from newborn calves to fully-grown adults.
Forty-three were already dead when found on the isolated beach; another six died during the rescue attempt and nine were refloated the following day at Matai Bay.
Tutukaka based marine conservationist Wade Doak said it was unlikely the answer to why the second stranding occurred in the same region will be found.
"There are places that are recurring stranding sites, like Farewell Spit, but the Far North coast is not known for frequent strandings," Mr Doak said.
He has swum with stranded whales and dolphins when their echo-sounding capabilities have not worked on a flat, shallow seabed. He said says people also become disoriented on flat, shallow seabeds when they can not use their vision to locate landmarks.
"Whales are social mammals and won't abandon the rest of the pod.
"While that works in their favour much of the time, this kind of situation proves it can be detrimental to the pod's well-being, too," he said.
Rescuers struggled in soft sand and against the ferocious sting of windblown sand to reach whales beached in a mass stranding on one of Northland's most remote beaches.
Joyce Munns, manager of nearby Waitiki Landing Holiday Park, said she will never forget the sound of the dying whales' "high-pitched screams".
Yesterday's stranding at Spirits Bay, 90km north of Kaitaia and between Cape Reinga and North Cape, was even bigger than last month's at Karikari Beach. Again, it involved pilot whales.
Atrocious weather conditions combined with crashing surf meant rescuers faced a hard job to save the whales from drowning or being dashed against rocks. Some of the whales had to be euthanised because of their injuries.
The remaining whales were due to be transported by truck to Rarawa Beach this morning in a desperate attempt to save their lives.
Volunteers from Project Jonah, Far North Whale Rescue, and other DoC offices in Northland and Auckland, along with members of the local Te Hapua community put in a long night to help keep the surviving whales alive.
"They will be lifted up with big nets on to the back of trucks with straw or hay loaded on them," Project Jonah chairman Mark Simpson said.
It was not clear how many trucks would be involved in the move but more help from the public would be needed throughout the day.
Advertisement"More whales are still coming in. Pilot whales have very strong social bonds and they try to help each other so more keep getting stuck," Mr Simpson said last night.
Ms Munns said she and other helpers felt useless against the furious weather conditions and the inevitability that the whales they could see "bobbing around" beyond the surfline would also strand. Many did.
About 6pm, Ms Munns went home, unable to stay with other rescuers for the long night time vigil of trying to shift the whales above the surf line and keeping them wet.
The alarm was raised at 11.30am when 32 pilot whales were reported stranded. By 2pm, 74 whales were stranded along a 2km stretch of beach. Of those, 49 were still alive. During the afternoon only nine had been refloated.
Kaitaia area manager Jonathan Maxwell said considerable effort and manpower will be required to save so many whales, with up to five people required per whale. Anyone who can help is urged to report to Spirits Bay-Kapowairua campground, with wetsuit, warm clothing and wet weather gear, he said.
Human safety was the number one priority, so careful planning and co-ordination were crucial, Mr Maxwell said.
The stranding at Karikari Beach, just a month ago on August 20, involved 58 pilot whales ranging from newborn calves to fully-grown adults.
Forty-three were already dead when found on the isolated beach; another six died during the rescue attempt and nine were refloated the following day at Matai Bay.
Tutukaka based marine conservationist Wade Doak said it was unlikely the answer to why the second stranding occurred in the same region will be found.
"There are places that are recurring stranding sites, like Farewell Spit, but the Far North coast is not known for frequent strandings," Mr Doak said.
He has swum with stranded whales and dolphins when their echo-sounding capabilities have not worked on a flat, shallow seabed. He said says people also become disoriented on flat, shallow seabeds when they can not use their vision to locate landmarks.
"Whales are social mammals and won't abandon the rest of the pod.
"While that works in their favour much of the time, this kind of situation proves it can be detrimental to the pod's well-being, too," he said.
Scores of whales feared dead in New Zealand mass beaching
Telegraph.Co.UK, from Sept 23: Scores of whales feared dead in New Zealand mass beaching
A pod of about 80 whales was found stranded at Spirits Bay, 200 miles northwest of Auckland, the second mass beaching in the area in two months.
While 25 of the whales were already dead, the Department of Conservation called in 100 volunteers to help the remaining mammals survive.
"It's pretty cold and arduous for the people on the beach trying to save the whales," she told Radio NZ.
Ms Smith said heavy swells and high seas were making it impossible to refloat the whales at Spirits Bay and the department was considering using trucks to move them to a more sheltered beach about an hour's drive away.
Last month, 63 pilot whales stranded themselves near Kaitaia, about 50 miles away. Only nine survived.
Scientists are unsure why pilot whales beach themselves, although they speculate it may occur when their sonar becomes scrambled in shallow water or when a sick member of the pod heads for shore and others follow
A pod of about 80 whales was found stranded at Spirits Bay, 200 miles northwest of Auckland, the second mass beaching in the area in two months.
While 25 of the whales were already dead, the Department of Conservation called in 100 volunteers to help the remaining mammals survive.
"It's pretty cold and arduous for the people on the beach trying to save the whales," she told Radio NZ.
Ms Smith said heavy swells and high seas were making it impossible to refloat the whales at Spirits Bay and the department was considering using trucks to move them to a more sheltered beach about an hour's drive away.
Last month, 63 pilot whales stranded themselves near Kaitaia, about 50 miles away. Only nine survived.
Scientists are unsure why pilot whales beach themselves, although they speculate it may occur when their sonar becomes scrambled in shallow water or when a sick member of the pod heads for shore and others follow
Friday, September 24, 2010
New Study Affirms Gulf Oil Spill's Vastness: 4.4 Million Barrels; 'We Think It's A Really Good Ballpark'
Underwater Times: New Study Affirms Gulf Oil Spill's Vastness: 4.4 Million Barrels; 'We Think It's A Really Good Ballpark'
NEW YORK, New York -- BP's leaking oil well in the Gulf of Mexico was conclusively sealed this week, but even now, questions remain about the amount of oil that actually came out of it. Initially after the April 20 explosion, officials claimed that the flow could not be measured. Then, as public pressure for information mounted, they looked for ways to measure it, and started producing estimates: at first, 1,000 barrels a day; then 5,000; then 12,000 to 19,000; then upward from there.
Now, in the first independent, peer-reviewed paper on the leak's volume, scientists have affirmed heightened estimates of what is now acknowledged as the largest marine oil accident ever. Using a new technique to analyze underwater video of the well riser, they say it leaked some 56,000 to 68,000 barrels daily--maybe more--until the first effective cap was installed, on July 15. Their estimate of the total oil escaped into the open ocean is some 4.4 million barrels--close to the most recent consensus of government advisors, whose methods have not been detailed publicly. The paper appears in this week's early online edition of the leading journal Science.
"We wanted to do an independent estimate because people had the sense that the numbers out there were not necessarily accurate," said lead author Timothy Crone, a marine geophysicist at Columbia University's Lamont-Doherty Earth Observatory. After BP and government officials downplayed the possibility or importance of measurements, a wide spectrum of scientists, environmental groups and legal experts pointed out that the information was needed to determine both short- and long-term responses, and monetary liability.
The new study divides the flow rate into two periods: April 22 to June 3, when oil spurted from a jagged break in the riser; and after June 3, when the riser was cut, and oil temporarily spewed into the ocean unimpeded. Crone and his coauthor, Lamont marine geophysicist Maya Tolstoy, used a visual analysis technique Crone recently developed called optical plume velocimetry. They say video from the earlier period indicated a flow of about 56,000 barrels a day (a barrel is 42 gallons). After the pipe was cut, they say, the rate went to about 68,000. After accounting for time elapsed, the authors subtracted 804,877 barrels collected by BP at the site, to come up with a total of 4.4 million barrels that escaped. Given the study's stated 20 percent margin of error plus or minus, this roughly agrees with the federal government's Flow Rate Technical Group's most recent comparable estimate of 4.1 million barrels (after subtracting the oil collected by BP).
Attempts to get a handle on the size of the release have been fraught with high-profile problems. A week after the initial 1,000-barrel-a-day assertion, it became apparent that BP was collecting more than that, and far more beside was escaping. On April 28, NOAA hastily produced an estimate of 5,000 barrels, extrapolating this from the size of the surface plume. But scientists and journalists soon attacked this figure (for instance in a May 13 New York Times report). Crone became involved when National Public Radio asked him and other experts to come up with their own estimates; a May 14 NPR story based on their observations suggested that the rate was actually five or ten times higher. On May 21, the Times published an op-ed piece by Crone and colleagues from three other institutions outlining the case that existing scientific techniques could be used to form a realistic picture. On May 27, the government raised the estimate again, to 12,000-19,000 barrels per day. A variety of techniques went into this and the later, even higher, official estimates, but the government and its advisors have released only limited information on their techniques—again, raising criticism from the scientific community . This new study is the first to lay out the details of an analysis publicly in a report independently reviewed by other researchers.
Crone started developing optical plume velocimetry in 2006, in order to study natural hydrothermal vents—volcanically driven cracks and holes in the seafloor that shoot out buoyant, superheated jets of mineral-laden water. A jet from a leaking oil pipe is similar. The technique uses high-resolution video from underwater cameras to track the motion of turbulent billows and flows in the water, breaking down the movement pixel by pixel. Under a grant from the U.S. National Science Foundation, Crone tested it first in the lab, then at deep-sea vents in the eastern Pacific, and the Juan de Fuca ridge, off the U.S. Pacific northwest. He is currently developing a network of automatic cameras that will track vent activity on the Juan de Fuca. "This is a great example of how basic research that doesn't seem to have any immediate value suddenly gains huge immediacy for society," said Crone.
The scientists say their study is just a start. Other researchers have been trying to get at the same question using separate visual and acoustic techniques. Crone and Tolstoy say their conclusions rest on just a few short clips of high-resolution video—almost all that has been released by BP and the government so far, and made available by members of Congress to the scientists. (A live publicly accessible webcam showing the leak as it continued week after week had extremely low resolution, insufficient for analysis.) The researchers point out that the flows could have varied day to day. And, the analysis did not include video of several other leaks from smaller holes further up the pipe, which are thought to have grown with time; thus, the true figures may be larger, if anything, said Crone. "We clearly acknowledge the limits of our technique; we're unlikely to ever know the exact figure," he said. Tolstoy added: "This is not the last word. It is the first peer-reviewed word. But we think it's a really good ballpark."
The researchers said they hope they and others will be able to refine their estimates if the government and BP release more video and other information to independent researchers. Ian MacDonald, a Florida State University oceanographer who has also studied the leak, but was not involved in the study, said: "This is a welcome paper in that it opens the door onto how the oil spill flow-rate estimates have been calculated. It provides a transparency of method and a foundation for peer review for what has until now been a confusing and uncertain process."
NEW YORK, New York -- BP's leaking oil well in the Gulf of Mexico was conclusively sealed this week, but even now, questions remain about the amount of oil that actually came out of it. Initially after the April 20 explosion, officials claimed that the flow could not be measured. Then, as public pressure for information mounted, they looked for ways to measure it, and started producing estimates: at first, 1,000 barrels a day; then 5,000; then 12,000 to 19,000; then upward from there.
Now, in the first independent, peer-reviewed paper on the leak's volume, scientists have affirmed heightened estimates of what is now acknowledged as the largest marine oil accident ever. Using a new technique to analyze underwater video of the well riser, they say it leaked some 56,000 to 68,000 barrels daily--maybe more--until the first effective cap was installed, on July 15. Their estimate of the total oil escaped into the open ocean is some 4.4 million barrels--close to the most recent consensus of government advisors, whose methods have not been detailed publicly. The paper appears in this week's early online edition of the leading journal Science.
"We wanted to do an independent estimate because people had the sense that the numbers out there were not necessarily accurate," said lead author Timothy Crone, a marine geophysicist at Columbia University's Lamont-Doherty Earth Observatory. After BP and government officials downplayed the possibility or importance of measurements, a wide spectrum of scientists, environmental groups and legal experts pointed out that the information was needed to determine both short- and long-term responses, and monetary liability.
The new study divides the flow rate into two periods: April 22 to June 3, when oil spurted from a jagged break in the riser; and after June 3, when the riser was cut, and oil temporarily spewed into the ocean unimpeded. Crone and his coauthor, Lamont marine geophysicist Maya Tolstoy, used a visual analysis technique Crone recently developed called optical plume velocimetry. They say video from the earlier period indicated a flow of about 56,000 barrels a day (a barrel is 42 gallons). After the pipe was cut, they say, the rate went to about 68,000. After accounting for time elapsed, the authors subtracted 804,877 barrels collected by BP at the site, to come up with a total of 4.4 million barrels that escaped. Given the study's stated 20 percent margin of error plus or minus, this roughly agrees with the federal government's Flow Rate Technical Group's most recent comparable estimate of 4.1 million barrels (after subtracting the oil collected by BP).
Attempts to get a handle on the size of the release have been fraught with high-profile problems. A week after the initial 1,000-barrel-a-day assertion, it became apparent that BP was collecting more than that, and far more beside was escaping. On April 28, NOAA hastily produced an estimate of 5,000 barrels, extrapolating this from the size of the surface plume. But scientists and journalists soon attacked this figure (for instance in a May 13 New York Times report). Crone became involved when National Public Radio asked him and other experts to come up with their own estimates; a May 14 NPR story based on their observations suggested that the rate was actually five or ten times higher. On May 21, the Times published an op-ed piece by Crone and colleagues from three other institutions outlining the case that existing scientific techniques could be used to form a realistic picture. On May 27, the government raised the estimate again, to 12,000-19,000 barrels per day. A variety of techniques went into this and the later, even higher, official estimates, but the government and its advisors have released only limited information on their techniques—again, raising criticism from the scientific community . This new study is the first to lay out the details of an analysis publicly in a report independently reviewed by other researchers.
Crone started developing optical plume velocimetry in 2006, in order to study natural hydrothermal vents—volcanically driven cracks and holes in the seafloor that shoot out buoyant, superheated jets of mineral-laden water. A jet from a leaking oil pipe is similar. The technique uses high-resolution video from underwater cameras to track the motion of turbulent billows and flows in the water, breaking down the movement pixel by pixel. Under a grant from the U.S. National Science Foundation, Crone tested it first in the lab, then at deep-sea vents in the eastern Pacific, and the Juan de Fuca ridge, off the U.S. Pacific northwest. He is currently developing a network of automatic cameras that will track vent activity on the Juan de Fuca. "This is a great example of how basic research that doesn't seem to have any immediate value suddenly gains huge immediacy for society," said Crone.
The scientists say their study is just a start. Other researchers have been trying to get at the same question using separate visual and acoustic techniques. Crone and Tolstoy say their conclusions rest on just a few short clips of high-resolution video—almost all that has been released by BP and the government so far, and made available by members of Congress to the scientists. (A live publicly accessible webcam showing the leak as it continued week after week had extremely low resolution, insufficient for analysis.) The researchers point out that the flows could have varied day to day. And, the analysis did not include video of several other leaks from smaller holes further up the pipe, which are thought to have grown with time; thus, the true figures may be larger, if anything, said Crone. "We clearly acknowledge the limits of our technique; we're unlikely to ever know the exact figure," he said. Tolstoy added: "This is not the last word. It is the first peer-reviewed word. But we think it's a really good ballpark."
The researchers said they hope they and others will be able to refine their estimates if the government and BP release more video and other information to independent researchers. Ian MacDonald, a Florida State University oceanographer who has also studied the leak, but was not involved in the study, said: "This is a welcome paper in that it opens the door onto how the oil spill flow-rate estimates have been calculated. It provides a transparency of method and a foundation for peer review for what has until now been a confusing and uncertain process."
Colossal coral bleaching kills up to 95 percent of corals in the Philippines
MongaBay.com: Colossal coral bleaching kills up to 95 percent of corals in the Philippines
It is one of the most worrisome observations: fast massive death of coral reefs. A severe wide-scale bleaching occurred in the Philippines leaving 95 percent of the corals dead. The bleaching happened as the result of the 2009-2010 El Niño, with the Indian Ocean and Southeast Asia waters experiencing significant thermal increase especially since the beginning of 2010.
In one of our conservation sites prior to the bleaching event, dead coral represented only 20 percent of all corals, after bleaching that percentage rose to 95 percent of corals. The dominant live coral morphologies on the reef flat included branching, encrusting and foliose forms (Acropora and Montipora species) followed by sub-massive and massive Porites species. The crest had a slightly lower percentage of encrusting and massive forms, and an increased percentage of tabulate and corymbose forms. In contrast, slope regions were dominated by foliose (Montipora species). Now, the majority of the coral are dead and are mostly covered by algae while some are already showing signs of rubble.
Millepora coral in the Philippines prior to bleaching event. Photo courtesy of Pierre Fidenci.
The bleaching has been observed at many other sites around the Philippines featuring mass mortality of corals including the coral triangle outside the Philippines. This environmental catastrophe will probably be considered the most damaging bleaching event ever recorded in the Philippines, surpassing the big one of 1998.
During bleaching events, corals loss the symbiotic algae (known as zooxanthellae) which causes the coral to look white as the limestone skeleton becomes visible. Corals that are not able to recover from bleaching will die and eventually break down. While corals can recover from bleaching, extreme or long exposure to temperature anomalies cause significant mortality. Recoveries are strongly influenced by human disturbances such as overfishing and water pollution.
The consequence of this large-scale event is far from being fully known but fish diversity and populations will be highly affected. Livelihood depending on small sustainable fishing activities will see their income significantly reduced. Tourism will suffer greatly and tourists activities to replace diving will be needed.
Prior to this year’s bleaching, it was estimated that about 85 percent of the reefs have been damaged or destroyed in the Philippines, now the current estimate is likely to be close to 95 percent.
It is one of the most worrisome observations: fast massive death of coral reefs. A severe wide-scale bleaching occurred in the Philippines leaving 95 percent of the corals dead. The bleaching happened as the result of the 2009-2010 El Niño, with the Indian Ocean and Southeast Asia waters experiencing significant thermal increase especially since the beginning of 2010.
In one of our conservation sites prior to the bleaching event, dead coral represented only 20 percent of all corals, after bleaching that percentage rose to 95 percent of corals. The dominant live coral morphologies on the reef flat included branching, encrusting and foliose forms (Acropora and Montipora species) followed by sub-massive and massive Porites species. The crest had a slightly lower percentage of encrusting and massive forms, and an increased percentage of tabulate and corymbose forms. In contrast, slope regions were dominated by foliose (Montipora species). Now, the majority of the coral are dead and are mostly covered by algae while some are already showing signs of rubble.
Millepora coral in the Philippines prior to bleaching event. Photo courtesy of Pierre Fidenci.
The bleaching has been observed at many other sites around the Philippines featuring mass mortality of corals including the coral triangle outside the Philippines. This environmental catastrophe will probably be considered the most damaging bleaching event ever recorded in the Philippines, surpassing the big one of 1998.
During bleaching events, corals loss the symbiotic algae (known as zooxanthellae) which causes the coral to look white as the limestone skeleton becomes visible. Corals that are not able to recover from bleaching will die and eventually break down. While corals can recover from bleaching, extreme or long exposure to temperature anomalies cause significant mortality. Recoveries are strongly influenced by human disturbances such as overfishing and water pollution.
The consequence of this large-scale event is far from being fully known but fish diversity and populations will be highly affected. Livelihood depending on small sustainable fishing activities will see their income significantly reduced. Tourism will suffer greatly and tourists activities to replace diving will be needed.
Prior to this year’s bleaching, it was estimated that about 85 percent of the reefs have been damaged or destroyed in the Philippines, now the current estimate is likely to be close to 95 percent.
Thursday, September 23, 2010
Jaws exposed: Extraordinary pictures of great whites stripping a whale carcass shows they're actually quite picky eaters
Daily Mail Online: Jaws exposed: Extraordinary pictures of great whites stripping a whale carcass shows they're actually quite picky eaters
Ever since Jaws, great whites have had a reputation as killing machines that has never seemed much point questioning.
However, that could all be about to change - after a study into the fearsome predators' dining habits.
Scientists towed a 36ft Brydes whale carcass into a well-known hunting ground for the animals in an exercise aimed at documenting how they tackled the huge free lunch.
And these amazing pictures show how up to 30 of them stripped a single whale carcass - and gave an 'extraordinary' insight into how the much-feared predators behave.
But while many would have expected a feeding frenzy and potentially lethal fights between the razor-teethed gians, the behaviour observed was quite different.
The sharks appeared to select choice cuts of the dead whale and did not appear to be aggressive towards each other.
Free lunch: The 30 great white sharks were provided with a whale carcass so scientists could study their eating habits
Tasty findings: Alison Kock was the principal scientist at Save Our Seas Shark Centre and Shark Spotting Programme, at Cape Town in South Africa and was surprised by the sharks
Alison Kock, 33, the principal scientist at Save Our Seas Shark Centre and Shark Spotting Programme, at Cape Town South Africa, said: 'Contrary to their reputation as mindless killers, the level of selectivity for which parts of the dead whale they ate was extraordinary.
'They targeted the energy-rich blubber, often making repeated "test bites" where no flesh was removed, and removing flesh only once they had determined it was what they wanted. If they got a mouthful of muscle, they often spat it out.
'They were very picky.'
It's thought the huge whale was killed after being struck by a boat and was found floating towards Miller's Point near Cape Town, South Africa, where the clean up operation for the local authorities would have been difficult as their huge bodies are harder to remove on land.
It was also feared the body - giving off oils that attract predators like sharks - may have drawn in great whites to an area frequented by swimmers.
Kock added: 'Permission was granted by the authorities to have the dead whale towed to nearby Seal Island where the carcass was less of an issue and the sharks could help solve the clean-up problem.
'In addition it provided an unparalleled opportunity to document white shark behaviour and record the number of sharks in the area.
'Whale carcasses are believed to be a very important source of food for white sharks with some scientific evidence suggesting they follow whale migrations possibly to, opportunistically feed on dead or sick whales.'
Jaws: Alison Koch said: 'Contrary to their reputation as mindless killers, the level of selectivity for which parts of the dead whale they ate was extraordinary'
Blubber: During the nine-day experiment Kock and her team made some shocking discoveries, including the fact that the sharks seemed to have a huge preference for soft blubber over tough muscle
During the nine-day experiment, which ended on Saturday, Kock and her team made some shocking discoveries, including the fact that the sharks seemed to have a huge preference for soft blubber over tough muscle.
'In the case of the whale carcass the sharks knew exactly what they wanted,' said Kock.
'It provides evidence that when they bite into a surfboard, or kayak or person wearing a wetsuit they can immediately determine it's not something they want to eat.
'It's very common in attacks on humans for white sharks to take a single bite and leave it at that. Our study provides more evidence that they are simply tasting and looking for meat that is nutritious. It shows that they are not just swimming around mindlessly eating everything they come across, as they are sometimes portrayed.'
She added: 'I was surprised at the total number of white sharks that fed on the dead whale over the nine days we documented the event. We recorded over 30 different sharks in total. At one stage we had up to four white sharks feeding simultaneously on the carcass.
'The first two days were the busiest with the most sharks, and the activity slowly decreased as the sharks had their fill. The last two days we recorded no sharks feeding on the carcass.
'Many of the sharks I recognised as individuals hunting seals around the island from this shark season, as well as previous years. We used their unique dorsal fins to identify them, but there were also new sharks that I had never seen before.
'The sharks showed very little aggression towards one another in the presence of such a large food source, often feeding side by side.
'Some of the sharks we observed were gorging on the blubber and you could actually see their bellies getting fuller.
"Some would arrive quite skinny and by the end of their session they looked pregnant with their bellies bulging.'
During the study, the sharks reduced the carcass down to less than seven feet (two metres) of bone and muscle, having removed all the blubber.
Shark enthusiast Kock, added: 'This is the ultimate example of the very important role sharks play in the ecosystem. That of recycling life, and of keeping our oceans healthy by removing dead and decaying animals like dead whales.'
Ooooooooh, Barracuda
Vancouver Sun: Secrets of barracudas revealed in thesis
Ottawa's Amanda O'Toole swam with barracudas to help determine where and how they live, Tom Spears reports.
Everyone in the Caribbean knows the barracuda, a big, tough predator that watches curiously from a short distance away when humans snorkel or dive around coral reefs.
Yet the big fish is a mystery. Does it swim long distances or stay at home? Where does it spawn? If you catch and release one, does it survive?
Carleton University student Amanda O'Toole of Ottawa found almost no one had studied the barracuda except for one guy from Miami in the 1960s. That's unusual for a top predator in any ecosystem. People study lions, tigers, grizzlies. Why not barracudas?
So off she went to study the fish for her master's thesis in biology.
It fit nicely with O'Toole's interests:
Enjoys working outdoors. Check.
Likes conservation. Check.
Likes to travel to the Bahamas in winter. Definitely.
"They're a very common fish," she says. That's one reason to study them; often scientists only get around to studying animals once they're endangered, leaving questions about what a healthy population looks like.
To conserve a species, you have to know where and how it lives, says O'Toole's adviser, Carleton professor Steven Cooke.
"When we started working on them, we were blown away" by the knowledge gap, he says.
O'Toole swam with her barracuda, feeling no fear. Attacks on humans are rare and usually seem to occur when the diver is carrying something that looks like a fish, she believes.
"They're fun to photograph. They're just really cool fish."
The barracuda is important both to the ecosystem and for sport fishing. Often they're caught by accident by someone looking for mahi mahi or other sport fish, but some people also try to catch barracuda.
That led to one question: Does a barracuda that's released recover? Mostly yes, she found. "They're quite robust" but they still have to be treated gently to avoid injury.
"These areas are quite predator-heavy, so there are lots of sharks or other barracuda around, ready to chomp a vulnerable fish as you release it."
She also studied a common toxin that some fish absorb called ciguatera, which can poison humans. The question was whether fish in one area carry more toxin than fish from a few kilometres away.
Yes, the local residents say.
No, her results showed, because the barracuda loves to travel.
"We put tags inside of barracuda. We have all these little listening stations set up on the ocean floor" near the island of Eleuthera, and these devices recorded where the fish moved.
Some stayed in one spot, but others moved around freely. "Our little telemetry array spans about 14 kilometres square, and sometimes these fish will zip straight across it in a day."
One even swam from her area to another fish-monitoring base 100 kilometres away, and back.
Some mysteries remain, though. The fish disappear for months in the summer, presumably leaving the continental shelf for the deep regions lying nearby. They may be spawning.
O'Toole has just finished her master's and moved to Vancouver, where she'll work for a consulting firm that studies the effects of development on fish.
She's happy to be working with fish, "but I'll miss my barracuda."
Ottawa's Amanda O'Toole swam with barracudas to help determine where and how they live, Tom Spears reports.
Everyone in the Caribbean knows the barracuda, a big, tough predator that watches curiously from a short distance away when humans snorkel or dive around coral reefs.
Yet the big fish is a mystery. Does it swim long distances or stay at home? Where does it spawn? If you catch and release one, does it survive?
Carleton University student Amanda O'Toole of Ottawa found almost no one had studied the barracuda except for one guy from Miami in the 1960s. That's unusual for a top predator in any ecosystem. People study lions, tigers, grizzlies. Why not barracudas?
So off she went to study the fish for her master's thesis in biology.
It fit nicely with O'Toole's interests:
Enjoys working outdoors. Check.
Likes conservation. Check.
Likes to travel to the Bahamas in winter. Definitely.
"They're a very common fish," she says. That's one reason to study them; often scientists only get around to studying animals once they're endangered, leaving questions about what a healthy population looks like.
To conserve a species, you have to know where and how it lives, says O'Toole's adviser, Carleton professor Steven Cooke.
"When we started working on them, we were blown away" by the knowledge gap, he says.
O'Toole swam with her barracuda, feeling no fear. Attacks on humans are rare and usually seem to occur when the diver is carrying something that looks like a fish, she believes.
"They're fun to photograph. They're just really cool fish."
The barracuda is important both to the ecosystem and for sport fishing. Often they're caught by accident by someone looking for mahi mahi or other sport fish, but some people also try to catch barracuda.
That led to one question: Does a barracuda that's released recover? Mostly yes, she found. "They're quite robust" but they still have to be treated gently to avoid injury.
"These areas are quite predator-heavy, so there are lots of sharks or other barracuda around, ready to chomp a vulnerable fish as you release it."
She also studied a common toxin that some fish absorb called ciguatera, which can poison humans. The question was whether fish in one area carry more toxin than fish from a few kilometres away.
Yes, the local residents say.
No, her results showed, because the barracuda loves to travel.
"We put tags inside of barracuda. We have all these little listening stations set up on the ocean floor" near the island of Eleuthera, and these devices recorded where the fish moved.
Some stayed in one spot, but others moved around freely. "Our little telemetry array spans about 14 kilometres square, and sometimes these fish will zip straight across it in a day."
One even swam from her area to another fish-monitoring base 100 kilometres away, and back.
Some mysteries remain, though. The fish disappear for months in the summer, presumably leaving the continental shelf for the deep regions lying nearby. They may be spawning.
O'Toole has just finished her master's and moved to Vancouver, where she'll work for a consulting firm that studies the effects of development on fish.
She's happy to be working with fish, "but I'll miss my barracuda."
Subscribe to:
Posts (Atom)