Friday, April 29, 2011

Ice Whale winter habitat 98% ice-covered

A research paper published in February but which received little attention in the popular press is a fascinating example of why narwhals could be considered the most extreme marine mammal on the planet.  The paper reports on an aerial survey of Baffin Bay in April 2008 that highlights the challenging conditions that narwhals live under in winter.
“During their migration, the ice begins to chase them south and they arrive in their wintering grounds and the ice just forms right around them,” explained biologist Kristin Laidre, who conducted the study.  “They become enveloped by the ice.  It’s very dense ice...and the ice floes are constantly changing, the leads are constantly opening and closing.”
Laidre’s objective in conducting the aerial survey was, in part, to quantify the amount of open water where the narwhals were found.  By combining the data collected on the aerial survey with satellite images of the sea ice, she determined that just two percent of the area surveyed was open water, and there were 18,000 narwhals there, or 77 narwhals per square kilometer of open water.
Narwhals surface to breathe in narrow opening in the sea ice. Photo by BBC.

“That means you have this large density of animals that need open water to breathe packed into a very small amount of habitat,” she said.  “The overall habitat area is large, but what’s actually usable to them is quite small.”
It is amazing to me that these remarkable animals can thrive in these conditions, where the risk that the ice could freeze over and provide no access to catch their breath seems absurdly high, where the area often appears totally frozen over to the naked eye, but somehow they eke out a living there.
It got me wondering why the narwhals stay there, when just 10 or 20 or 30 miles further south there is far less ice and the living conditions would be much easier. The answer, Laidre said, is partly because that’s simply how they have evolved.  “They really have a niche, they’re totally adapted to this pack ice, more than any other northern hemisphere cetacean, and they don’t have many competitors.  Why go further south when you’re adapted to live in the pack ice and don’t need to go further?”
But there’s more to it than that.  She said that it probably also has a great deal to do with competition and the partitioning of resources.  Narwhals, belugas and bowheads are the only whales that spend their entire lives in the Arctic, but there is a large pool of more southerly whales and marine mammals that come to the Arctic in summer to feed in its highly productive ecosystem.  Those subarctic species avoid the Arctic when it’s dark and ice-covered and miserably cold in the winter but move in during the spring and stay throughout the summer and early fall.  The narwhal has developed a strategy to exploit the ecosystem at a time when there are few competitors in an area where they know they have a reliable food supply available.  When the ice recedes, the Arctic whales move north just as the slew of subarctic species arrive in the area they just left.
“There are also theories that the narwhals avoid killer whales by living in the pack ice,” Laidre said.  “I don’t necessarily think that’s the case, because there are basically no killer whales in the Arctic in the winter.  There’s no good reason to just hide in the ice when, at that time, there is nothing to hide from.”
It’s just one more reason to be in awe of the ice whale of the Arctic.

Friday, April 22, 2011

Narwhals no fan of military, industrial noises

The news this week that the U.S. Navy is going to be allowed to “incidentally” harass marine mammals during tests of their sonar systems and unmanned submarines in the waters around Washington State is certainly worrisome in itself.  But it comes on the heels of an announcement that the Navy plans live fire tests in the Gulf of Alaska where the exercises could cause harm to whales and a report that training by the Navy off San Diego last month has been linked to at least three dolphin deaths.
                While most Americans will recognize the necessity of training by the Navy, there must be places it could be held where cetaceans are less likely to be affected.  A couple dozen species of marine mammals reportedly live in or pass through the area where the Washington State tests are to be conducted, and the Gulf of Alaska is famous for its marine mammal spectacle.
                It can be argued that military sonar has not been proven to negatively affect large baleen whales, but even the Navy admits that smaller toothed whales, especially beaked whales, are particularly sensitive to this type of sonar and are often killed or beach themselves. Although to my knowledge no military sonar tests have been conducted in the range of the narwhal, this species is a small toothed whale and is probably not immune. 
                Every narwhal biologist will agree, however, that narwhals are quite sensitive to even the slightest unnatural noise in their environment.  Inuit hunters told me that if they aren’t especially careful when paddling their kayaks and make a slight splashing noise, any nearby narwhals will dive and disappear.  The noise from the increased shipping and exploratory drilling for oil and minerals that is already resulting from the retreat of Arctic sea ice, while perhaps not killing the animals outright, is certain to cause them to abandon feeding, resting and breeding areas.  And during stressful times when the animals are competing for food and mates, these unnecessary and dangerous noises are the last thing they need. (Shipping noise is also known to be destructive to other marine life, including squid and octopus.)
                These man-made noises are also likely to affect communication by narwhals and their use of echolocation.  Little is known about narwhal vocalizations, though it is believed they have a sophisticated sound-based means of finding food and exploring their environment, much like many other cetaceans.  One scientist even believes that individual narwhals can be distinguished by their unique sounds, somewhat like a human accent or voice.  But those voices are of little use to them if they are being drowned out by military and industrial noises.

Sunday, April 17, 2011

Narwhals and Their Melting World

Last week’s news reports note that scientists now predict that the Arctic will be ice-free in summer as early as 2016.  While that may be somewhat welcome news to shipping companies seeking a more reliable route through the Northwest Passage or for oil exploration companies anticipating a longer working season, or even for those southern Greenlanders looking for a longer growing season, it is not good news for many Arctic marine mammals that depend on that ice as a feeding or resting platform or for a reliable place to find food.  And that certainly includes narwhals.
             A recent research study concluded that narwhals and polar bears are the Arctic species at greatest risk from a warming climate.  While the polar bear situation has been told many times, few reports have described how narwhals will be affected.  Kristin Laidre, a narwhal researcher at the University of Washington, told me that the impact of climate change on narwhals may come from a wide range of factors.  
View from Qaanaaq, Greenland, Aug. 2010

“These include not only sea ice loss, but also changes in ocean regimes, such as altered ocean temperatures, salinity or currents that may change distribution of prey,” she said.  “There are also human impacts.  There is considerable interest in oil exploration and drilling in the Arctic as the region warms and sea ice disappears.  This comes with increased shipping, for example, through the Northwest Passage, as well as other activities that could potentially disrupt migratory routes and feeding areas, such as competition from developing fisheries, noise and pollution…If you’re a species that relies on specific predictable prey resources and you go exactly where they are found, then if something happens and the system changes you have to be able to adapt your behavior.  To some extent, these indirect impacts may make narwhals more vulnerable than the direct impacts of sea ice loss.”
It’s the narwhal’s inflexibility that seems to make it more vulnerable to changes in its marine environment.  They have very specific habitat and dietary needs, and warming waters may move their preferred foods north and away from their preferred habitat.  The northward expansion of southern species of whales, especially killer whales (a main predator on narwhals), could end up increasing competition for food and alter predator-prey relationships.  It could also make them more vulnerable to disease, especially new diseases that may expand their range into the Arctic. The melting ice has also triggered plankton blooms, which provide the basis of the food web, to occur 50 days earlier than they did just 15 years ago.  And that could mean that food availability during important times of year will shift, with uncertain affects on narwhals and other whales.
So while narwhal populations are presently somewhat healthy, the warming climate makes their future precarious.

Monday, April 11, 2011

In Search of the Right Whale

Photos by Cynthia Brown, Provincetown Center for Coastal Studies

Long before I began my research into the life history of narwhals, I spent time learning about what may be the rarest mammal in North America, the North Atlantic right whale, for my 2007 book about endangered species in New England.  Instead of having to travel to the Arctic to see my target species as I’ve done for the last few years, I was treated to great views of right whales somewhat nearby in Cape Cod Bay, thanks to the generosity of Stormy Mayo and the Provincetown Center for Coastal Studies.
                This past weekend I returned to Provincetown with my wife Renay to see if we could get a look at the whales from shore, something she had never seen before despite repeated attempts.  Stormy told me that the whales had been congregating just offshore in the days leading up to the weekend, and he was right.  It only took us a few minutes to see our first right whale, and over the course of three days we saw more than a dozen whales cavorting within binocular-viewing of Race Point and even from our motel room window overlooking Provincetown harbor.
                Right whales breed off the coast of Georgia and northern Florida and migrate north in time to arrive in the waters around Cape Cod in late winter and early spring to feed on the abundance of copepods – shrimp-like crustaceans smaller than a grain of rice – that are found in the area at this time of year.  It’s a treacherous trip for the whales, and the news media has reported several becoming entangled in fishing gear and others dying from ship strikes or unknown causes during the journey this year.  But thankfully many of the whales survived the trip and put on quite a show for us.
                We watched as the whales cavorted in entertaining ways, like tail slapping, spy-hopping and my favorite behavior, skim-feeding – opening their mouths above the water’s surface and skimming food from the top of the water column.  While the whales were sometimes hard to see and even more difficult to count this weekend, from a distance it was easy to see the mist emitted from their blowholes as they surfaced for air and their frequent display of their flukes as they began a deep dive.  Right whales are impossible to misidentify, since they are the only large whale in the area that doesn’t have a dorsal fin, so we were confident of our sightings, though we did see one whale in the vicinity with a dorsal fin, which may have been a sei whale.
                Nonetheless, it was wonderful weekend of marine mammal sightings, which included looks at a pod of harbor porpoises and a gray seal (as well as an unfortunate look at a dead Atlantic white-sided dolphin on the beach).  While there is no guarantee of seeing whales from shore, and there are no commercial whale-watching trips at this time of year, a winter weekend in Provincetown in search of our rarest whale is absolutely worth the trip.

Thursday, April 7, 2011

Hunting the Ice Whale

            I have always struggled with the concept of sport hunting, regardless of whether the species being hunted is abundant or not.  Killing for fun is an idea that is completely alien to me. But I have always supported subsistence hunting, at least philosophically. That position was put to the test last summer when I traveled to northern Greenland to observe a narwhal hunt by members of the local Inuit community.
            I was impressed with the traditional hunting practices they employed – handmade kayaks and harpoons thrown by hand – and by the respect they appear to have for the animals and for the health of the narwhal population. The hunters made it clear to me that in the village of Qaanaaq, the northernmost municipality on Earth, they have little access to fresh produce or packaged foods, and so they must live on whatever they can harvest by their skill and determination. 
            These photos provide a visual summary of my experience in Qaanaaq, where I left feeling comfortable with my support of subsistence hunting and with one hunter’s affirmation that, despite his wish that the village quota of 85 narwhals be doubled, no one ever continues hunting after the quota is met.

Inuit hunters scan the fjord for narwhals.
Hunter Mads Ole Kristiansen paddles off in his homemade kayak.
Mads Ole tosses his harpoon at a surfacing narwhal.
The successful hunter.
Close-up of female narwhal harvested by Inuit hunters.

Monday, April 4, 2011

Geeks hijack narwhal and beluga

Despite the vast ways to keep track of the latest news about narwhals and other marine mammals in the Arctic, it’s also increasingly challenging to do so because both the narwhal and beluga have been hijacked by the high-tech world.  An online search of news about narwhals usually turns up an abundance of stories and blogs about the Ubuntu Natty Narwhal, which is apparently the latest open source operating system produced by Linux.  And searching on beluga finds that it is the name of a new group messaging application that was just purchased by Facebook.
On the one hand, the names given to these programs are causing plenty of geeks to take a moment to learn a little about the Arctic marine mammals that the products are named for, as is evidenced by several articles by IT columnists, like these in the Manila Standard Today and The Atlantic.  And I learned a little from these articles, too.  Like the fact that earlier versions of related Linux products have been named after an alphabetical listing of wildlife, the most recent of which (before narwhal) are ibex, jackalope, koala, lynx and meerkat.  I bet the next one will be opossum.  Or oriole.
But at the same time, I worry that the real narwhals and belugas will lose their identities in the mass of high-tech marketing for these products. The whales are already among the lesser known marine mammals on the planet, largely because their Arctic ranges are far from human populations. Rather than becoming even more obscure, the whales need to have additional attention brought to their amazing life cycles, behaviors and habitat, which is the purpose of this blog in the first place. 
But I can’t do it alone.  So give these amazing whales the props they deserve.  If you find yourself using the high tech products named for the narwhal and beluga, make sure to give your friends and colleagues a natural history lesson by sharing what you know about the whales so they get a little benefit from their namesake products.  It’s the least we can do.

Friday, April 1, 2011

Who doesn't love a parade?

My wife and I are going to spend a couple days on Cape Cod next weekend in an effort to see one of the world’s rarest mammals, the North Atlantic right whale, which feed in Cape Cod Bay in early spring each year.  In conducting research for a book several years ago, I had lots of great views of the whales from aboard a research vessel operated by the Provincetown Center for Coastal Studies.  And the most amazing thing I saw was what I described in my book as a right whale parade as the animals repeatedly swam back and forth in front of me while skim-feeding copepods from the water with their mouths wide open and their heads above the surface.  I’ll never forget it.
            But right whales aren’t the only whales that can put on a parade.  During my time camping last summer in Tremblay Sound, on Baffin Island, Canada, the narwhal research team and I had a chance to watch a narwhal parade almost every six or eight or ten hours.  And it’s hard to describe the spectacular feeling it gave me every time I saw it.
            We would usually hear the whales well before they arrived, with their repeated surfacing for air making little splashing noises and their breathing making somewhat similar sounds.  On several occasions, the narwhals announced their appearance with a wide variety of vocalizations that sounded like farm animals, squeaky doors, whistles and clicks.  As you can see in this video, they paid little attention to us as they swam by, but a pod of 200 narwhals certainly attracts attention from the human population, and I couldn’t get enough of them.
            The only downside was that the researchers were trying to capture several narwhals during our three-week encampment, but every time the animals approached the nets set out in the water, they easily maneuvered around or under them and they continued casually on their way. As frustrating as it was for the scientists, it also made us admire the whales even more.