#WhaleWednesday – Bowhead Whale

 

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One of just three year-round Arctic whale species, bowheads, are famous for their massive bow-shaped heads, designed perfectly for one of their main challenges: getting through think sea ice to breathe. Bowheads are able to use their large reinforced skulls and powerful bodies to break through ice 20cm think. Although Inuit hunters in Alaska have reported whales surfacing though approximately 60cm of ice. Their Heads make up about a third of the total length – which in adults can be up to 20 metres – newborn calves are about 4 metres long and weigh 2-3 tonnes.

Bowhead whales are also known in quiet Arctic waters for their intense bouts of social group interactions, involving tail and flipper slapping, as well as breaching (leaping entirely out of the water) – which is an impressive feat for whale that weigh up to 100 tonnes.

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Whales are close to the top of the food chain and important indicators of overall health of the marine environment. The bowhead whale’s conservation status is listed as “Least Concern” overall, however some populations, such as the East Greenland-Svalbard population are endangered.

Data has shown that bowhead whales may be among the longest-lived animals on earth. Based on the recovery of stone harpoon tops in their blubber, and from analysis of eye tissue, scientists believe that the life span of bowhead whales can be over 100 years.

Bowhead whale, Arctic

Like the other ice whales (beluga and narwhal), bowheads also have no dorsal fin, enabling them to move easily under the sea ice. Bowheads can dive for over 30 minutes at a time. They typically spend the entire year in Arctic waters, their travels shaped by the melting and freezing of the ice, and seasonal movements to a series of spring-summer productive feeding areas. They have a very thick layer of blubber – approx 40-50cm – which serves primarily as an energy store to see them through the annual cycle.

Bowhead whale, Isabella Bay, Nunavut, Canada

Bowheads are baleen whales, with about 250-350 keritanous baleen plates on each side of their upper jaw. These massive vertical plates – up to 4.6m long in fully grown individuals, the largest of any whale – to filter their food from the hug open-mouth gulps of water that they take. Bowhead whales need to eat about 100 tonnes of food annually, mainly tiny crustacean zooplankton. Most of their annual feeding occurs in the summer months, and much of that in the Canadian waters.

The bowhead whale has been a victim of the appeal of its long baleen plates and thick blubber – the most economically valuable whales. Hunted by commercial whalers until the last century for whale oil and baleen, bowhead whales are still recovering slowly from their economic extinction. While some populations are faring better as a result, it will take many more decades for this long lived and slow reproducing species to recover to its pre-whaling numbers. Inuit in Canada, Greenland and Alaska are allowed a limited subsistence hunt for bowhead whales.

Threats: Modern threats to bowhead whales include sea ice retreat and changes to food web dynamics due to rapid climate change and ocean acidification. Bowheads are also affected by direct and indirect impacts of increased development such as oil and gas exploration, commercial shipping, and fishing.

The Canadian and Alaskan governments have attached satellite radio transmitters to a sample of bowhead whales, in order to better understand seasonal movements and habitat use of these Arctic giants. This information can be sued to identify and protect the most important areas used by these whales, and to help plan further human activities, like shipping and development, in these sensitive, quiet arctic waters – the bowheads’ home –  and in all decisions regarding the future of Arctic marine systems facing rapid climate and economic change.

 

 

#WhaleWednesday – Gray Whale

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Gray whales have a hump and a ridge of sharp bumps along their back, instead of a dorsal fin, and can be between 40 and 50 feet long. They are a type of baleen whale, meaning they filter food from the water through special bristly structures in their mouths. Gray whales stay close to shore and feed in shallow water. Their migrations take them between feeding and breeding areas, swimming as much as 12, 000 miles per trip.

Critically endangered western gray whales migrate into their summer feeding grounds near Sahkalin Island, Russia in May or early June and then return to their winter feeding grounds in the the South China Sea in late Autumn.

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The eastern population of the gray whale can be found in the Bering and Chukchi Seas between Alaska and Russia during the summer feeding. In the winter, the eastern gray whale migrates south along the west coast of the US to Mexico to breed and have their calves.

The Gulf of California’s San Ignacio Lagoon is one the best places in the world to see gray whales with their calves. The calm, warm waters of the lagoon are a safe place for young whales, free from predators like killer whales. Locals in the area, call gray whales “friendly ones” as they have an unusual tendency to approach whale watching boats and check out the occupants.

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Threats: Oil and gas development, entanglement in fishing gear, and collisions with ships threaten gray whales. The western North Pacific gray whale is on the verge of extinction because of such threats. The waters off Russia’s Sakhalin Island, a main feeding habitat for them in the summer, are being targeted for oil and gas development. In the eastern Pacific Ocean, the potential for oil and gas exploration in the Bering and Chukchi Seas also exists. Whales are very sensitive to noise and such industrial activities generate massive underwater booms. The gray whale must get an entire year’s worth of food during those summer months and any disruption could have significant impact on this process.

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Friendly Gray Whales in San Ignacio Lagoon

#WhaleWednesday – Fin Whale

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The fin whale, the second largest living mammal, has been severely impacted worldwide by commercial whaling. Nearly 750,000 animals were killed in areas of the Southern Hemisphere alone between 1904 and 1979, and they are rarely seen there today. Their current status is unknown in most areas outside of the North Atlantic.

The fin whale is the world’s second largest animal after the blue whale. They can dive to depths of 230 metres and make low-frequency noises (infrasound) which can be as loud as 188 decibels. These sounds cannot be heard by humans, but can be detected by other fin whales up to 850 km away. An individual fin whale is identified by the pattern of light-coloured chevrons on its back as well as by the size and shape of its dorsal fin. Records of females have been found with multiple foetuses, but it is unlikely that more than one would survive. The oldest specimen captured in Antarctica was 111 years old. Fin whales have also been known to mate with blue whales and to produce first generation offspring.

Growing up to 27 metres long and weighing as much as 120 tonnes, the slender body of the fin whale is capable of speeds of up to 37km/h, with brief bursts of up to about 47km/h which led to its nickname, ‘greyhound of the sea’. The upper half of the body is dark grey or brownish, while the belly is white. The head has a single medial ridge and has distinctive asymmetrical markings: on the right side the lower lip, mouth cavity and baleen plates are white, whereas on the left these features are dark. The fin whale has a small, falcate dorsal fin and slightly concave trailing edges to its flukes, which are rarely raised out of the water.

The fin whale feeds on animal plankton (including krill) and schooling fishes, lunging to take in great quantities of water and prey, then filtering the water out through its baleen plates leaving the prey trapped inside its mouth. When a fin whale eats it often turns on its side with the right side facing downward; in this position the lighter head colouration makes it less visible to prey. The fin whale generally travels alone or in pairs, and rarely breaches or spyhops. Its exceptionally large size, asymmetrical head colouration and small dorsal fin are probably the best identifying features. Overall range and distribution is not well studied but they are known to inhabit primarily pelagic habitats of both northern and southern hemispheres. Most populations are thought to be migratory whilst several resident populations are known to exist in the Gulf of California, East China Sea and the Mediterranean.

Extinction Risk:

Fin Whale

 

 

 

Threats:

With krill reduced, will they go too? Fin whales have been greatly affected by historical hunting, mostly due to their economically valuable blubber, oil and baleen. The recovery of the southern hemisphere fin whale may be undermined by, among other things, a reduction of Southern Ocean krill due to climate change.
Pollution: Fin whales are also threatened by habitat degradation. In some regions they have been shown to carry high levels of pollutants such as heavy metals, PCBs and other organochlorine compounds that accumulate with age and transfer between mother and calf during nursing. These substances can cause health and reproductive problems in cetaceans.
Ship strikes: Boat collisions are another serious cause of fin whale mortality, particularly in areas with high-speed vessel traffic. A dead fin whale that was washed ashore in south-west England in early 2010 is believed to have been the victim of a ship strike.

Bycatch: They are also vulnerable to incidental catches in fishing gear, but less so than many other cetacean species.

Whaling: Whaling remains a threat for this species. In 2006 Iceland resumed commercial whaling and in 2009 set a quota for 150 fin whales over 5 years – to date 125 fin whales have been harvested – despite the species’ status as “Endangered”.

Note: Japan is also set to return to a full-scale commercial whaling on the high seas, a move currently blocked by the International Whaling Commission (IWC). But the Japan government has consistently ignored objections and resolutions from the IWC against its scientific whaling and has even ignored a decision by the International Court of Justice that they close down their whaling activities as undermining the IWC. The new Japanese legislation includes funding to repair the aging whale ships being used for the current bogus “scientific” whaling and guarantees funding for whale “research” in the future. Furthermore, the new legislation allows Japan to send vessels to Antarctica with the fleet specifically to deal with harassment from such organizations as the Sea Shepherd Conservation Society, which seeks to interfere with whaling activities they contend violate international law. (Memo to Japan government: Sea Shepherd is right.)

 

Japan has also moved to stop interference with their illegal whaling operations by declaring that anyone who opposes whaling and the killing of dolphins is a terrorist.

Apparently, simply witnessing and documenting the slaughter of dolphins in Japan will now be a crime and classified as terrorism.

#WhaleWednesday – Narwhal

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The narwhal looks like a cross between a whale and a unicorn with its long, spiraled tusk jutting from its head. Males most commonly have tusks, and some may even have two. The tusk, which can grow as long as 10 feet, is actually an enlarged tooth. The tusk may also play a role in the ways males exert dominance.

Narwhals are related to bottlenose dolphins, belugas, harbor porpoises, and orcas. Like some other porpoises, they travel in groups and feed on fish, shrimp, squid, and other aquatic fare. They are often sighted swimming in groups of 15 to 20, but gatherings of hundreds—or even several thousand—narwhals have been reported. Sometimes these groups become trapped by shifting pack ice and fall victim to Inuit hunters, polar bears, or walruses.

Whales, like the narwhal, are at the top of the food chain and have an important role in the overall health of the marine environment. Narwhals are also culturally important to indigenous communities in the Arctic. Like polar bears, the narwhal depends on sea ice for its existence and can be directly impacted by climate change.

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Extinction Risk 

Narwhal

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Threats faced by Narwhals:

Oil and Gas Development – Vessels that support oil and gas development mean increased shipping in sensitive areas. Increased shipping means more noise that can mask communications for many Arctic marine species and it increases the potential for collisions with marine mammals, especially whales. It also brings more pollution and a greater possibility of oil or fuel spills.

Ocean Noise – Shipping, industrial extraction, marine construction and military activities cause underwater noise pollution. Since whales depend on sound to communicate, any interference by noise pollution can negatively affect their ability to find food and mates, navigate, avoid predators and take care of their young.

Climate Change – Thousands of years of evolution have prepared Arctic species like the polar bear, walrus and narwhal for life on and around the sea ice. Because of climate change, that ice cover has been changing rapidly, in both extent and thickness, and shrinking far too quickly for these species to adapt. A narwhal’s entire life is connected to sea ice, both as a place to feed and a place to take refuge. Slow swimming whales rely on sea ice as a place to hide from predators like killer whales.

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#WhaleWednesday – Blue Whale

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The blue whale is the largest animal to ever live, in the entire history of Earth. Reaching lengths of at least 110 feet (33 meters) and weights of 209 tons (190 tonnes), these animals are only slightly smaller than the United States Space Shuttle. Their incredible size is only possible because of their aquatic lifestyles and the buoyancy provided by seawater. On land, an animal as large as the blue whale would almost certainly be crushed under its own weight.

Interestingly, though they are enormous, blue whales are not predatory.  They filter feed for tiny krill and are totally harmless to people (other than through accidental collisions).  This life history strategy is common among several large animals in the ocean, including the whale shark, the basking shark, and the other great whales.  Like all whales, blue whales are mammals and give live birth to very large calves that they nurse for six or seven months.  Because the female is responsible for providing milk for its babies, she must store extra energy reserves and is consequentially larger than males.  All of the record blue whales (by size) are females.  Males do not provide parental care and do not seem to live near the females/young for most of the year.

Blue whales have a truly global distribution and live in every ocean except the parts of the Arctic that remain covered with ice throughout most of the year (including summer).  There are three distinct populations of blue whales (North Atlantic, North Pacific, and southern hemisphere), and individuals are known to undergo very long migrations between feeding grounds near the poles and calving grounds in the tropics.  Their very large size may help blue whales (and other migrating animals) survive such long trips through waters that may provide relatively little food.

Unfortunately, blue whales were one of the hardest hit species by commercial whaling, and they have been slow to recover since their worldwide protection in 1966.  Experts continue to view them as endangered (highly vulnerable to extinction) and estimate their numbers to be only three to ten percent of what they were before whaling.  Today, a primary threat to blue whale recovery is accidental interactions with fishing gear and with ships, but their numbers are slowly increasing.  To compound their trouble, however, blue whales’ preferred food source – krill – is now fished commercially.  Their recovery from commercial whaling is in direct competition with commercial fishers in the Southern Ocean.  As that fishery takes more and more krill, the slow increase in numbers of blue whales may stop or even be reversed.

#WhaleWednesday – Beluga Whales

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The beluga whale is a relatively small toothed whale that is brown-gray at birth and bright white in adulthood. The beluga is one of just two species in the “white whales” family, the other being the narwhal. As they are closely related and do not have the characteristic tusk of the males, juvenile and female Narwhals can be incorrectly identified as belugas.

Belugas, however, are typically more solidly white than their grayish cousins.  Adult belugas are also slightly larger than Narwhals, reaching lengths of around 18 feet (5.5 m).  Interestingly, the beluga whale is the only species of cetacean (whales and dolphins) that has a movable neck.  Belugas can move their heads up and down and from side to side.

Beluga whales are restricted to the Arctic Ocean and adjacent waters.  They feed in shallow, coastal waters during the summer and near the ice edge in winter.  Some populations undergo long, seasonal migrations, while others are more resident in nature.  They eat a variety of fish and invertebrate prey.  Killer whales and polar bears have been known to attack and eat beluga whales.  Scientists believe that belugas may swim far into ice-covered waters to avoid Killer Whales but that this may put them in greater risk of predation by Polar Bears.

Occasionally, belugas can be observed far inland, swimming up coastal rivers as far as hundreds of miles.  Scientists do not know if these trips into freshwater are for feeding or for other purposes, but belugas are apparently unafraid of very shallow water.  In fact, some individuals have been known to survive being stranded/beached by patiently waiting for the return of the high tide.  Belugas are also known for their loud, clear vocalizations.  They often “sing,” and can even be heard above the ocean surface by people in boats or onshore.

Northern Manitoba’s Hudson Bay coastline is home to the world’s largest population of beluga whales. More than 57,000 beluga whales gather in the region between mid-June to mid-September.

You can check out Explore.org live cams in Churchill: it’s the office season now – but the live cam highlights are definitely worth checking out!

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http://explore.org/live-cams/player/beluga-boat-cam-underwater

Conservation scientists consider the beluga to be near threatened with extinction.  Climate change is causing rapid changes to the Arctic ecosystem that affect beluga habitat, and chemical pollution in the Arctic is particularly bad, risking the health of large predators like this species.  These whales are hunted, legally, by indigenous peoples all around the Arctic, but this ongoing hunt is not generally thought to threaten the species.  Climate change and pollution are likely more significant threats to beluga populations, though further research is necessary before accurate predictions can be made.

 

#WhaleWednesday – Humpback Whale

The humpback whale is a charismatic species of large whale that has a truly global distribution, living from Antarctica to the Arctic and from the coast to the open ocean. The humpback whale is one of the largest animals on Earth, growing to lengths of more than 50 feet and weights of 40 tons. This incredible size is only possible because of this species’ aquatic lifestyles and the buoyancy provided by seawater. On land, an animal as large as the humpback whale would almost certainly be crushed under its own weight.

Interestingly, though they are enormous, humpback whales are not predatory.  They filter feed for tiny krill or small pelagic fishes and are totally harmless to people (other than through accidental collisions).  This life history strategy is common among several large animals in the ocean, including the whale shark, the basking shark, and the other great whales.  Like all whales, humpback whales are mammals and give live birth to very large calves.  These whales are known for their singing; during courtship, the males compose intricate songs to attract females.  The killer whale is the only species known to attack and eat humpback whales (always juveniles).

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Humpback Whale – Victoria, BC – Photo Credit Mel Komus

Every year, humpback whales undergo incredible migrations between feeding and breeding grounds.  They feed near the poles and give birth in the tropics, and each year, individual humpback whales travel as much as sixteen thousand miles (25,000 km) between these two areas.  They only eat in their winter feeding grounds and live off fat reserves for the rest of the year, including while migrating.

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Humpback Whale – Victoria, BC – Photo Credit Mel Komus

During the height of commercial whaling, the humpback whale was hunted almost to extinction.  Global populations declined by more than 90% before regulators enacted a worldwide moratorium on hunting in 1966.  Fortunately, the humpback whale has recovered remarkably well, and populations continue to increase.  Now, this great whale has come all the way back from the brink of extinction to be considered a species of least concern.