A new study funded by the U.S. navy and the Office of Naval Research show that Beaked whales are at higher risk of developing decompression sickness since they live with extremely high levels of nitrogen in their blood and body tissues. This may explain why beaked whales seem to be especially susceptible to naval sonar. If the sonar causes the animals to surface more rapidly than they would normally do, e.g. because they are frightened by the underwater sounds, it may lead to decompression sickness which may in turn explain the strandings associated with naval sonar exercises.

Decompression sickness, commonly referred to as “the bends” among scuba divers, is a consequence of the sudden drop in pressure that occurs when you ascend rapidly from the deep. When mammals dive, nitrogen builds in our bodies. If we ascend slowly the nitrogen isn’t dangerous, but if we ascend too quickly the nitrogen forms bubbles inside the body. Tiny bubbles might not sound like anything to fuzz about, but within the body it can be lethal.

Beaked whales are believed to accumulate large amounts of nitrogen within their bodies since they make repeated dives to such great depths. They can stay submerged without breathing for long periods of time and are capable of descending down to nearly 1,500 metres. Having this inclination for decompression sickness may explain why beaked whales seem to be more vulnerable to naval sonar than other marine mammals.

“It provides more evidence that beaked whales that are being found dead in association with naval sonar activities are likely to be getting decompression sickness,” said Robin Baird, a marine biologist at Cascadia Research Collective and one of the report’s authors.

The study has focused on three species of beaked whale: Cuvier’s beaked whale (Ziphius cavirostris), Blainville’s beaked whale (Mesoplodon densirostris), and the Northern bottlenose whale (Hyperoodon ampullatus). The Northern bottlenose whale was studied off the cost of Nova Scotia, Canada while the two others were observed around Hawaii, U.S.

According to a 2006 report in the Journal of Cetacean Research and Management, 41 known cases of mass strandings of Cuvier’s beaked whales have occurred since 1960. Some of them have happened at the same time as naval sonar exercises in the area, including Greece in 1996, the Bahamas in 2000, and the Canary Islands in 2002. When the beaked whales stranded in Bahamas were autopsied, they turned out to have bleedings around their brains and ears; bleedings which may have been caused by nitrogen bubbles.

The U.S. navy has agreed to adopt certain practises to protect whales, but is resisting more stringent restrictions until more scientific evidence is at hand. The navy has budgeted 26 million US per year over the next five years to fund marine mammal research on how these animals are affected by sound.

If you wish to find out more about the beaked whale study, it is published online this week in the journal Respiratory Physiology and Neurobiology.

This Saturday, about 55 False killer whales (Pseudorca crassidens) stranded on Long Beach, Kommetjie, in South Africa. Both adults and calves began to appear on the shore around 5.30 in the morning, perhaps as a result of the bad weather. This incident is the second large stranding in a short period of time; in March about 80 whales stranded in Hamelin Bay on Western Australia’s southern coast.

Massive whale strandings are however not new phenomenon; Long Beach was for instance the site of a heartbreaking stranding in 1928 when 103 whales beached on Christmas Eve. This was before marine experts and volunteers had figured out how to save stranded whales, so all 103 animals died in the scorching sun. This was also during a period when whales were chiefly seen as something that you hunted; not something worth saving.

So, why do whales beach? Scientists are still in the dark on when it comes to this bewildering question and no hypothesis has been confirmed yet. In his book “Whales and Dolphins of the Southern African Subregion”, whale researcher Peter Best lists a long row of hypotheses – all of the seemingly plausible – and also states that whale strandings may be due to a combination of several factors.

“It is very likely that no single cause is responsible and elements of some hypotheses may have to act in combination to produce the circumstances for a mass stranding to occur”, Best explains.

Here are some hypotheses put forward by marine scientists:

• Parasites infesting the middle ear can cause severe disorientation and make it difficult for whales to navigate. If one or several animals in a group develop middle-ear problems, the other ones might follow them due to their social bonding, even if it means stranding on a beach.
• An injured or sick whale may send out a distress call that the others follow all the way up on the beach.
• If cetaceans navigate using the earth’s geomagnetic field, geomagnetic disturbances could make them disorientated and, if they’re unlucky, even cause them to beach.
• Beachings may be a density-dependent response, where a population approaching its carrying capacity suffers increased natural mortality.
• Whales hunting for food close to the shoreline may accidently strand themselves in the pursuit.
• Whales might end up on beaches after getting caught in a rip current, getting their sonar confused. A rip current (also known as rip tide) is a strong surface flow of water returning seaward from near the shore.
• Beaked whales seem to be extra sensitive to mid-range sonar, so human activities may be to blame for the stranding of beaked whales.

The 2009 whaling season has now started in the waters off Iceland.

Iceland and Norway are the only two countries that openly defy the international whaling moratorium; Japan is instead using a loop whole, claiming their whaling to be carried out for scientific purposes.

Former Icelandic fisheries minister Steingrimur Sigfusson said in February that Iceland would make no changes to its whaling quotas of 150 Fin whales and up to 150 Minke whales per year.

“The first batch of meat will be in stores by the weekend,” says Gunnar Bergmann Jonsson, manager of the Minke Whaler Association. He said 50 to 60 per cent of the meat will be sold domestically, while the rest is sold to Japan.

The first whales are usually killed in a bay outside Reykjavik, since whaling is prohibited close to the harbour. The prohibition has been imposed to prevent whalers from disturbing whale watchers, since that may cause damage to the Icelandic whale watching business.

The Icelandic whaling season usually runs from May to late September.

Whale facts
Also known as Little Piked Whales or Lesser Rorquals, Mink Whales prefer icy waters but are found world-wide. Once perceived as one single species, the population has quite recently been recognized as consisting of two distinct species: the Northern Mink Whale, Balaenoptera acutorostrata, and the Southern Mink Whale, Balaenoptera bonaerensis. Together, the two species are believed to form a population of over 1 million Minke Whales world-wide. Balaenoptera acutorostrata is listed as Least Concern on the IUCN Red List of Threatened Species, while Balaenoptera bonaerensi is listed as Data Deficient since it was recognized as a separate species so recently.

The Fin Whale (Balaenoptera physalus) is also found world-wide, with 40,000-56,000 specimens living in the North Atlantic. Unlike the Mink Whale, the Fin Whale is listed as Endangered on the IUCN Red List of Threatened Species.

Photograph created by Erik Christensen. Taken on the Faroe island not Island.

The Snubfin dolphin (Orcaella heinsohni), recognized as a species as recently as 2005, have been spotted while utilizing a rare hunting technique previously only noted in the Irrawaddy dolphin (Orcaella brevirostris), a close relative of the Snubfin.

The unusual group hunting technique involves chasing the prey fish to the surface of the ocean and rounding them up by spitting jets of water at them. Once the fish is packed together in a reasonably small “cylinder”, the dolphins move in to devour them.

According to WWF Australia’s marine and coasts manager Lydia Gibson, the behaviour was first noticed in Australia off the Kimberley Coast.

We still know very little about the Snubfin dolphin, which lives along Australia’s northern coast in a number of locations off the Queensland and Northern Territory coasts, as well as the Kimberley region of Western Australia. It is listed as Near Threatened on the IUCN Red List of Threatened Species, chiefly due to habitat destruction. Since Snubfin dolphins live close to shore, they are also more likely to end up in gill nets and drown compared to more pelagic species of dolphin.

Thanks to a system of underwater hydrophones, scientists have been able to document the presence of North Atlantic Right whales in an area where they were believed to have gone extinct.

The North Atlantic Right whale (Eubalaena glacialis), where even the name is a reference to it being the “right” whale to hunt, was heavily targeted by whalers during the 19^th and 20^th century and the entire species was on the brink of extinction when the moratorium on whaling was implemented in the 1960s.

Being an important whaling area throughout the 19^th century, Cape Farewell Ground off the southern tip of Greenland was believed to have no surviving population of Right whales, but when scientists from Oregon State University (OSU) and the National Oceanic and Atmospheric Administration (NOAA) begun investigating the area using hydrophones, they recorded a total of 2,012 Right whale “calls” from July through December 2007.

“We don’t know how many right whales there were in the area,” says David Mellinger, assistant professor at OSU’s Hatfield Marine Science Center in Newport and chief scientist of the project. “They aren’t individually distinctive in their vocalizations. But we did hear right whales at three widely space sites on the same day, so the absolute minimum is three. Even that number is significant because the entire population is estimated to be only 300 to 400 whales.”

During the last 50 years no more than two Right whales have been sighted at Cape Farewell Ground, so even a figure as low as three during the same day is good news.

The project has been using five hydrophones engineered by Haru Matsumoto at OSU, configured to continuously record ambient sounds below 1,000 Hz over a large region of the North Atlantic. These underwater hydrophones are sensitive enough to record sounds from hundreds of miles away. The scientists used previous recordings of Atlantic and North Pacific Right whales to identify the species’ distinct sounds, including a type of vocalization known as “up” calls.

“The technology has enabled us to identify an important unstudied habitat for endangered right whales and raises the possibility that – contrary to general belief – a remnant of a central or eastern Atlantic stock of right whales still exists and might be viable,” says Mellinger.

Results of the 2007 study were presented this week at a meeting of the Acoustical Society of America in Portland, Oregon.

In addition to Mellinger and Clapham, scientists involved in the project include Sharon Nieukirk, Karolin Klinck, Holger Klinck and Bob Dziak of the Cooperative Institute for Marine Resources Studies – a joint venture between OSU and NOAA; Phillip Clapham, a right whale expert with NOAA’s National Marine Mammal Laboratory, and Bryndís Brandsdóttir of the University of Iceland.

Japan needed to cede more ground, says outgoing head of the International Whaling Commission (IWC) William Hogarth*, voicing regrets over his failure to design a compromise regarding Japanese “lethal research” on whales.

After a meeting next month in Portugal, Hogarth will step down as both US delegate and head of the world whaling body. While announcing his disappointment in leaving the chairmanship without having resolved the “scientific whaling” issue, Hogarth also said that his efforts brought civility to the IWC, where annual meetings had long been showdowns between pro- and anti-whaling nations.

Norway and Iceland are the only nations that hunt whales in open defiance of the 1986 IWC moratorium; Japan is instead using a loophole in the moratorium that allows for lethal research.

In a series of closed-door negotiations with Japan and other nations lead by Hogarth, Japan allegedly offered to reduce but not end its annual Antarctic whale hunts; an offer which infuriated the neighbouring countries Australia and New Zealand.

Japan accuses Western nations of cultural insensitivity and is currently pushing for the IWC to accept whaling of the coast of Japan, since whaling is a time-honoured Japanese tradition.

One of the highlights of Hogarth’s time as head of the International Whaling Commission was a compromise brokered by him in 2007, in which Japan agreed to suspend plans to expand its hunt to include Humpback whales – a species that haven’t been hunted by Japanese whalers for several decades.

* William Hogarth is a biologist and dean of the University of South Florida’s College of Marine Science.

Indonesia will create Southeast Asia’s largest marine park in the Savu Sea, Minister of Marine Affairs and Fisheries Freddy Numberi said on Wednesday at the World Ocean Conference in Manado, Sulawesi.

The Savu Marine National Park will cover 3.5 million hectares in an incredibly diverse area where you can find no less than 500 coral species, over 300 recognized species of fish and a lot of charismatic wildlife like sea turtles, sharks, dolphins and whales. Out of 27 known species of whale, no less than 14 migrate through the Savu Sea to get from the Pacific to the Indian Ocean. The Savu Sea is also an important spawning ground for many marine species, including the world’s dwindling tuna population.

Indonesia is famous for its prosperous marine environment, but this marine flora and fauna are today facing serious treats, including pollution, over fishing and the use of unsustainable fishing methods. Lax enforcement of Indonesian law has made it possible for fishermen to continue using illegal fishing methods such as dynamite and cyanide fishing.

Within the Savu Marine National Park, efforts will be made to eradicate illegal fishing practises while keeping certain areas open for local fishermen to continue traditional subsistence fishing. Tourism activities will also be allowed in certain designated areas within the park. Environmental groups, including WWF and The Nature Conservancy, will help set up the reserve together with the Indonesian government.

“Enforcement is one of the key questions we need to work out, said Rili Djohani”, marine expert at The Nature Conservancy. “It could be a combination of community-based and government patrols.”

The Savu Marine National Park is located within the so called Coral Triangle, a coral reef network bounded by Indonesia, Malaysia, the Philippines, Papua New Guinea, East Timor and the Solomon Islands.

U.S. and Canadian scientists have documented the first known migration of blue whales from the coast of California to areas off British Columbia and the Gulf of Alaska since the 1965 ban of commercial whaling.

Researchers identified 15 separate cases where Blue Whales were spotted in the waters off British Columbia and the Gulf of Alaska. Four of the observed animals were identified as Blue Whales previously seen swimming in Californian waters, which suggests that Blue Whales are re-establishing their old migration pattern.

The identifications were made by comparing pictures of Blue Whales photographed in the northern parts of the Pacific Ocean since 1997 with photographs of Blue Whales taken off the southern U.S. West Coast. The identity of individual Blue Whales was determined based on dorsal fin shape and pigmentation patterns in skin colour.

The Blue Whale was almost hunted to extinction during the 20^th century and even though commercial whaling has been prohibited (albeit not strictly enforced) since 1965 the populations are having a hard time recovering. Blue Whales are still listed as endangered on the IUCN Red List of Threatened Species and no more than roughly 5,000 to 12,000 Blue Whales are believed to remain in our oceans, with 2,000 of them living of the U.S. West Coast.

The migration research was conducted by scientists from Cascadia Research Collective in Washington State, NOAA’s* Southwest Fisheries Science Center in California, and Canada’s Department of Fisheries and Oceans. You can read the full article in the most recent issue of the journal Marine Mammal Science.

* The United States National Oceanic and Atmospheric Administration (NOAA)

Amber, a porpoise living at the Harderwijk dolphin centre in the Netherlands, has given birth to a calf this spring, making her the second porpoise ever to give birth in captivity.

Visitors are now gathering to come and see the calf, which has been given the name Kwin.

Picture is GNU

“Mum Amber and her baby, Kwin, are doing fine,” the centre said in a statement on Thursday.

The sex of the calf has not yet been determined and will continue remain unknown for several weeks. Another conundrum concerns the paternity of the calf. According to the dolphin centre, two male porpoises were swimming with Amber at the time of conception and any of them may be Kwin’s father.

The very first porpoise ever to give birth in captivity lives in Denmark where it had a calf in 2007 and the Harderwijk dolphin centre is now enlisting the aid of Danish porpoise keepers to make sure that baby Kwin is properly cared for.

“As we don’t know much about newborn porpoises, a team of Danish minders has come to help us,” the centre says in its statement.

The porpoise is a small ocean-dwelling mammal related to whales and dolphins. There are six recognized species of porpoise and their common ancestor is believed to have diverged from the dolphins roughly 15 million years ago. Porpoises are not as large as dolphins and have stouter bodies with small, rounded heads. Compared to dolphins, wild porpoises bear young more quickly and some species give birth to a calf as often as once a year. However, porpoises do not adapt to life in captivity as well as dolphins do and successful reproduction in zoos is therefore extremely rare.

A research boat used by the National Oceanic and Atmospheric Administration (NOAA), a federal agency charged with protecting the endangered North Atlantic Right Whale, collided with one of the whales off the Massachusetts coast this Sunday.

The NOAA vessel Auk was on its way back from a research journey when a Right Whale surfaced just 10 feet in front of the boat. The boat collided with the whale and the propeller cut into the animal’s left tail fluke. According to NOAA spokesman David Miller, the lacerations on the left tail fluke did not appear to be life-threatening. Researchers followed the whale for about 45 minutes after the accident and it appeared to be OK.

The accident highlights how difficult it is to avoid whale collisions and how we must work even harder to learn new ways of keeping these animals safe from boats. Even with the special precautions taken by NOAA vessels, the calamity still happened.

“To me, if it can happen to NOAA, it can happen to anybody,” said Regina Asmutis-Silvia, a Plymouth-based biologist with the Whale and Dolphin Conservation Society. “Therefore, everybody needs to up the ante and up their vigilance and take the issue much more seriously.“

Ship strikes are currently the major threat to the North Atlantic Right Whale (Eubalaena glacialis). This year, a record number of calves were born in U.S. waters, but the population still comprises no more than roughly 400 animals.