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Arctic killers

A warmer North Pacific Ocean might be partly to blame for king-salmon-eating killer whales struggling in the Salish Sea of the Pacific Northwest, but climate changes appear to be opening rich, new hunting grounds for some of their northern cousins.

 

A hydrophone placed in the Chukchi Sea just north of the Bering Strait in 2009 has been picking up ever more sounds of killer whales talking to each other year by year, Kathleen Stafford at the Applied Physics Laboratory at the University of Washington reports in a paper published in Marine Mammal Science.

The report buttresses the observations of hunters and scientists from along Alaska’s remote and desolate northern Bering Sea, Chukchi and Beaufort Sea coasts.

“They’ve always been around based on local knowledge, but the aerial surveys essentially never saw them until the last decade,” said Craig George, an elder scientist based at the top of the world in Utqiaġvik, the community formerly known as Barrow.

“In the last five years, the first bowhead (whale) calf kills have been recorded,” George said Saturday. “So I’m pretty convinced the killer whale densities have increased in the northeast Chukchi and there may be more killer whales now.  Grays and bowheads are at historic levels, and fin (whales) humpbacks are now common in the Chukchi. Lots of food around for killer whales.”

The wolves of the sea, killer whales – orcas to some – would naturally try to exploit a new prey base, and the hydrophone data would indicate that is what is happening.

“Killer whale calls were detected every year from 2009 to 2015,” she wrote. “Signals were detected with increasing frequency in fall months (September to November) annually from 2009 to 2015, and in every month from June through November from 2013 to 2015.”

The hydrophone provides but a snapshot of a tiny part of the picture of what is going on in the region.

“The acoustic detections reported here are from a single site in the southern Chukchi Sea that is located where Bering Sea waters from both the eastern and western sides of the Bering Strait converge,” Stafford noted. “The detection range for killer whale calls under very low ambient noise conditions is on the order of at most 10 kilometers (6.2 miles), therefore only very small proportion of the southern Chukchi Sea was monitored during this study.

“The occurrence documented here should be considered minimum estimate of the time spent in the Chukchi Sea.”

Data collection was hampered by, among other things, the fact that “mammal-eating killer whales tend to be silent when hunting, only producing calls during social interactions or after a successful kill or when pursuing large prey,” Stafford wrote.

The thinking is that killer whales on the hunt travel silently so as not to alert prey of their presence in the area.

Given the limitations on the hydrophone data, Stafford expressed a belief killer whale numbers in the increasingly ice-free Alaska Arctic might be far higher than indicated.

“In the eastern Canadian Arctic, particularly the Hudson Bay area, killer whale sightings have increased exponentially since the 1950s,” she observed. “This increase has been partially attributed to decreases in seasonal sea ice at ‘choke points’ where heavy, multiyear sea ice has restricted their access in the past.

“The proportion of bowhead whales with killer whale rake marks, which are scars caused by an unsuccessful predation event, increased from 1986 to 2012 with an estimate of 10 percent of adults seen between 2007 and 2012 exhibiting interaction with killer whales.”

Residents and transients

Commercial fishermen in the Bering Sea have for years been complaining about a boom in whale numbers there. A 2014 study published in PLOS One concluded those fishermen were losing more than $500 per day to killer whales that had become masters at stealing fish off longlines.

“When I started fishing in the early ’80s, when we saw a whale it was an event,” Paul Clampitt, the Washington state-based skipper of the  F/V Augustine told Canada’s National Post in 2017. “Now, they circle the boat.”

These whales, however, are resident fish eaters, and interactions that bring them into contact with fishermen make them easier to track.

“We have over 700 individual resident killer whales photographed and catalogued in the waters stretching from southern Southeast Alaska to Kodiak Island and over 1,500 from the Aleutian Islands and Bering Sea shelf edge, and we are still discovering more with every field effort,” noted Alaska whale authority Craig Matkin wrote in the Journal of the American Cetacean Society.

Much less is known about the so-called transients that prey on other whales and marine mammals.

Although northern fur seals which breed in the Pribilof Islands are known to be prime prey for the transients, Maktkin said, only about 50 have been individually identified.

“Just what they do when they leave the Pribilofs is not certain,” he wrote, “but there is no doubt they travel substantial distances. One satellite-tagged whale headed southward more than 1120 miles into the subtropical transition region of the central North Pacific, nearly halfway to Hawaii.”

There have been indications, however, that the population has grown large enough to alter ecosystem in some places.

University of Alaska Fairbanks scientist Alan Springer and colleagues in 2003 suggested increasing killer whale predation likely caused an abrupt decrease in sea otters in Western Alaska and before that possibly in seals and sea lions.

“We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales’ foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus ‘fishing-down’ this element of the marine food web,” they said. “The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.”

Matkin, who estimates there are 350 killers using the waters around rookeries and haulouts, has questioned that. If they whales were only eating sea otters and sea lions, he wrote, they might be able to decimate those populations, but all indications are that the whales are feasting on a multitude of prey.

“…Our observations suggest some seasonal specialization (or) gray whales at migration time, or fur seals at breeding time,” he observed. “(But) stable isotope analysis of skin biopsy samples has shown that the spring/summer diet of transient killer whales in the Aleutian Islands is not composed exclusively or even primarily of Steller sea lions or sea otters, a finding
supported by field observation data indicating that gray whales, minke whales, and northern fur seals comprise a substantial portion of the their diet.

“Additionally, transient killer whales sampled in the Bering Sea have stable isotope signatures consistent with a largely cetacean diet (of) Dall’s porpoises, minke whales, and gray whales. We have not observed actual consumption of sea otters in this region, although there are a few accounts from other researchers.”

Available prey

Opportunistic hunters, the killer whales could well have shifted their hunting toward more plentiful prey after Western Alaska sea lion numbers plummeted in the 1980s and whales became more common.

The population of eastern grey whales has been increasingly steadily since the 1990s, and expanding ever northward into new habitat as Arctic Ocean ice retreats.

NOAA scientist Sue Moore suggested in 2016 that it was “boom times” for all the baleen whales in the Arctic and near-Arctic. Killer whales feed on those whales along with other marine mammals.

“A ‘new normal’ climate is emerging in the Pacific Arctic marine ecosystem, coincident with the dramatic loss of sea ice at a rate which accelerated after 2000,” Moore observed. “Overall, the region has lost 75 percent of sea ice by volume and 50 percent in late-summer surface cover, coincident with the extension of the open-water period by four to six weeks.”

Sea-ice loss that has been generally bad for polar bears, walruses and ice seals, she opined in that commentary for Biology Letters, but appears to have been  very good for whales.

“Satellite data suggest that this biophysical transformation supports increased rates of phytoplankton net primary production by 42 percent in the Chukchi Sea and 53.1 percent in the Beaufort Sea, probably in response to reduced sea ice thickness and extension of the open-water period,” she wrote.

Increasing volumes of phytoplankton, in turn, “probably supports higher rates of secondary production, including the mesozooplankton and forage fish prey of baleen whales,” Moore concluded. “This suggested link between sea ice loss and increased prey production is supported by limited observations in the Chukchi Sea, where the abundance and biomass of mesozooplankton was higher in reduced-ice years (2007/2008) compared with years with extensive sea ice (1991/1992).”

As the base of the pyramid-shaped food web grows, so too do the number of predators on up the web – salmon, pollock, pinnipeds, the little whales, the big whales, and finally at the top of the heap the highly predatory killer whales.

“At present,” Moore concluded, “conditions in the Pacific Arctic appear to be favourable  – i.e. ‘boom times’ – for all five species of baleen whales.”

Indications are that the boom times for baleen whales might now have trickled down to the killer whales coming north to join the mix in the bloody jungle that is the natural world, where the richness of an ecosystem, or lack thereof, is usually most  obvious in the volume of killing taking place.

Whether these changes are a good thing or a bad thing for the Arctic going forward only time will tell.

“Baleen whales also act as ecosystem engineers and their recovering numbers may actually buffer the marine ecosystem from destabilizing stresses associated with rapid change,” Moore wrote. “With more baleen whales recycling nutrients vertically and horizontally and, with increasing numbers of bowhead and grey whales re-suspending sediments during epibenthic and benthic foraging, the Pacific Arctic marine ecosystem will probably continue to change in ways now difficult to predict.”

So far, however, the warming of the Bering Sea and waters to the north has brought good times for any number of species from baleen whales to killer whales to salmon.

Bristol Bay at the southern edge of the Bering Sea is witnessing unprecedented returns of sockeye salmon, and Russia’s Kamchatka Peninsula on the eastern edge of the sea was overrun by the 2018 pink salmon return. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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23 replies »

  1. Although rarely mentioned today, back in 2011 scientists made a new discovery…
    “NASA Discovers Significant Ozone Hole Over The Arctic”
    The paper states that “chemical ozone destruction over the Arctic in early 2011 was – for the first time in the observational record – comparable to that in the Antarctic ozone hole.” “Unusually long-lasting cold conditions in the Arctic lower stratosphere led to persistent enhancement in ozone-destroying forms of chlorine and to unprecedented ozone loss, which exceeded 80 percent.”
    “The scientists cite the dramatic depletion of ozone over the region as an example how sudden anomalies can occur as a result of human activity that ended decades ago, in this case the release of chlorinated fluorocarbons (CFCs).”
    This example shows how human activity can lead to changes in our environment.
    It is also important to note that:
    “2016’s record meant that 16 of the 17 warmest years have occurred since 2000,[12] 2017 being the third-hottest year on record meant that 17 of the last 18 warmest years have occurred since 2000.”
    (Wikipedia)
    These hotter years we are experiencing correlate to the discovery of an 80 percent Ozone loss over the Arctic.
    This loss in Ozone only further exacerbates sea ice loss in the region as does the release of Methane gas from thawing permafrost throughout the North.

    https://www.thearcticinstitute.org/nasa-discovers-significant-ozone-hole-arctic/

    Like

  2. More “Cult of Catastrophe” crap. But hey that NY Communist in the House says we only have 12 years left……….……so eat, drink and be merry! For in 12 years we’re all gonna die Al Gore style.

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    • Your comment has nothing to do with this article. It is the definition of a strawman argument. I don’t see how Pelosi (I think that’s who you were referring to?) has anything to do with this story. Quick question for you: are you suggesting that arctic sea ice has not been diminishing over the past 30 years? Are you suggesting that killer whales do not modify their diets based on food availability? Or, was your comment an attempt at satirical humor? If so, kudos to you – nailed it!

      Cheers!

      Like

      • Pretty hard to say with Burt Jack, but he may have been referring to AOC (NY representative) referencing a recent UN report.

        Like

  3. “Arctic ice loss has tripled since the 1980s, with melting in places such as Greenland and Alaska providing the greatest instigator of sea level rise while destabilizing the very ground underneath 4 million people’s feet.”
    “The only thing we can do is adapt and mitigate further global warming – it’s too late for there to be no effect,” Bevis said. “This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point.”
    “We’re going to see faster and faster sea level rise for the foreseeable future. Once you hit that tipping point, the only question is: how severe does it get?”

    https://www.google.com/amp/s/amp.theguardian.com/world/2019/jan/21/greenland-ice-melting-faster-than-scientists-previously-thought-study

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  4. “Arctic sea ice is proving remarkably reluctant to enter its appointed ‘death throes’, despite the usual suspects having already planned the funeral. Climate Change Anxiety Disorder, it turns out, is yet to impose its angst on the actual climate, no matter how hard the BBC tries to make it.

    The latest observations show that Arctic sea ice is on course to have a greater minimum extent than in 2015 and 2016, and is running higher than levels seen a decade ago. Back then, the BBC reported that Arctic summers may be ice-free by 2013, although this estimate was described as being ‘too conservative’.

    That prediction was spectacularly wrong, and contrary to warnings of an ‘Arctic death spiral’, sea ice extent has been remarkably stable in the last decade. No one can say what exactly will happen next; if this humbling affair teaches anything it should be precisely that.

    The climate has misbehaved in other ways too. The Greenland Ice Sheet has been gaining mass at a record rate for the second year running, and Antarctic sea ice extent is perfectly normal relative to the 1981-2010 average. These facts get little coverage because they don’t sound alarming at all, and for most reporters that means they’re not news. These ‘inconvenient truths’ are nonetheless a helpful reminder that climate change coverage should be taken with a healthy dose of scepticism. There is a long way to go before we can make accurate predictions about how the climate will behave, if indeed we ever can.

    Climate science has to be more deeply grounded in real-world observations rather than models that are inevitably riddled with flawed human assumptions.”

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      • Thank God Obama lowered the rising sea levels. We owe our lives to that Community Agitator. Well, for another 12yrs anyhow.

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      • Bryan, are you suggesting that the ice caps (and most glaciers) are not shrinking on a decade by decade basis over the past 30 years? I’m just curious if I should move you from the serious doubter to outright denier category. Or, are you such an ideologue that you must shoot down any support of a contrary believe without looking at reality or using science to back up your claims? Let’s see some of your evidence (from serious sources – not from breitbart or infowars – maybe you could look at actual satellite images from 20 years ago vs today). Sorry, but I’m just not sure how I should take your comments.

        Cheers!

        Liked by 1 person

      • Jack, I am curious. Since MSNBC, CNN, NYT, Wash Post, etc.. all purposely had gotten the phony “Vietnam”, indian vet story wrong and Breitbart had gotten it right, you imply Breitbart isn’t a reliable source? How do you come to that conclusion? I am not sure how to take your response. Satire?

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      • If you are using the last 20-30 as a guideline then you are using the wrong information to form your opinion. The earth has been warming and cooling and warming and cooling for as long as it has existed. To better understand our most recent historical climate just look up the Pleistocene Epoch, Bill has been reading all about it can surely offer some knowledge on the subject.

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      • The present time will be known as the Steve-O Epoch, where his cojones shriveled up to nothing. He used to carry them around in a wheelbarrow but now keeps them in his watch pocket.

        Liked by 1 person

      • Bill, it’s been less than 24 hours since you said the following to another commenter:

        “All you do on here is show how retarded you are by attacking the messenger regularly, rather than the message.
        Try debating the subject sometime-you might find it refreshing but I suspect that debate is not one of your strong suits. Just my opinion!”

        Followed by:

        “can’t you get a grip-you don’t produce a single thing on these posts other than name calling.
        You must be really bored but if you want to debate a subject go ahead and give it a try. My guess is that all you got is name calling and doesn’t play well with others.
        Fuck off!”

        So you can dish it out but you can’t take it. Perhaps you should take your own advice?

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      • Steve-O, it’s looking like I struck a nerve. And if you look at the context you’ll see I was merely responding to your own post. You don’t like it? Tough Noogies!

        Liked by 1 person

      • Bill I think a 4 th grader has taken over your handle. His obsession with cajones and nuggies has clarified his age . Please nudge him off the key board . It will help the discussions .

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      • Bill not struggling with discussion as you already knew . Just very unimpressed with your 4 th grade posts that made me consider the possibility a preteen is using your handle or computer. As to my memory the Bill Yankee who usually posts is a fishing captain well educated on many specifics beyond 4 th grade tactics. I don’t agree with many of the posters on here but at least they present viable information that I learn from on a regular basis . I am often impressed with their knowledge and carefully lined out information. Kudos them even when I don’t agree .

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      • Hi Brian,
        Congratulations on using a source that I use on a regular basis (Forbes – obviously). All I’m going to say about Breitbart getting the ding dong kids vs the ding dong native protester vs the black Hebrew Israelites story mostly right – Even a blind dog will find a bone once in a while…

        PS – watch out for Forbes – they tend to get a bit click baity regularly. I think that’s how they attract people from Fox ;>) Cheers man!

        Like

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