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.

As reported earlier , the European Union has decided to ban the import of seal skin and other seal products hailing from commercial seal hunting.

This has upset Canadian seal hunters since Italy and Denmark, both members of the European Union, are two major importers of seal products. Italy imports most of their seal skins from Russia, but Denmark has always been an important trade partner for North American seal hunters, partly due to Denmark’s traditional connection to Greenland.

According to a statement from Canadian Trade Minister Stockwell Day, the federal government is now getting ready to move in with an appeal against the ban, which they see as a clear breach of WTO regulation.

“We’ll go to the WTO because it’s clear in WTO regulations that if one country wants to ban the products of another, it has to have clear scientific, medically acceptable reasons for doing so, and this EU ban is not based on hard science,” Day said.

The Canadin government believes that Canada deserves an exemption from the import ban since it follows internationally accepted guidelines regarding seal hunting, e.g. by prohibiting the clubbing of baby seals while they still have their white coats.

Day claims that the European ban is based on “people’s feelings” rather than hard facts, and says that the trade action will proceed unless the European Union Parliament exempts Canada and other countries that he said practise humane and sustainable seal hunting. According to Day, seal hunt proponents erroneously portray seal hunting as it was 40 years ago.

The suggested seal import ban must still be approved by individual European governments before becoming law but can, if passed, come into effect as early as next year. If the is approved, it will cause an annual 2 million USD loss for the Canadian industry.

Canadian Fisheries Minister Gail Shea agrees supports the government’s planned trade action.

“When you live in small coastal communities, sometimes there’s not many opportunities to make some additional money,” she said. “We have a number of families who make up to 35% of their annual income from the seal hunt. So yes, I do think it’s very important.”

As reported earlier, the proposed European seal import ban will contain some exemptions and seal products resulting from hunts traditionally conducted by Inuit and other indigenous communities can still be imported to and marketed in European Union countries even if the ban is approved. Products that result from hunting conducted for the purpose of sustainable management of marine resources on a non-profit basis will also be allowed, and individual travellers will be permitted to bring seal products to the European Union as long as the import is of an occasional nature and consists exclusively of goods for the personal use of the traveller.

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)