Steller's sea lions

The poor endangered Steller’s sea lions are surviving so poorly, and their populations decreasing alarmingly, at the point of Alaska’s Aleutian Islands that the Obama administration is stepping up, and calling for the immediate cease and desist order for the commercial fishing of two very prominent species of fish; the Atka mackerel and the Pacific cod.

This shutdown being proposed by the Obama administration would only hit a small, yet vital portion of Alaska’s largely Seattle-based fishing industry.

However, it is also the latest proof that the sea lions have become a proxy in a heated battle over fishing in Alaska. Both environmentalists and big Industry are keeping their eye on what’s happening to the $1 billion a year pollock industry in the Bering Sea nearby. The fishery there supplies half of the country’s catch of fish.

On Monday the fishing industry expressed their concerns at the rapid and sever proposal put out by the Obama administration. It should be noted however, that this proposal was made in response to a 45 percent drop in the western Aleutians’ sea lion population since 2000. That’s quite a dip in only 10 short years.

The National Marine Fisheries Service wants to have everything closed down and other preventative measures in place by next year.

“What they’ve put on the table today is a head shot for us,” exclaimed counsel for United States Seafood in South Seattle, Dave Wood.

Modern seals, walruses, and sea lions are all descendants of animals that once lived on land but eventually swapped their terrestrial lifestyle for a life in the ocean. Until now, the morphological evidence for this transition from land to water has been weak, but researchers from Canada and the United States have now found a remarkably well preserved skeleton of a newly discovered carnivorous animal: Puijila darwini.

Skeletal illustration of Puijila darwini.
Credit: Mark A. Klingler/Carnegie Museum of Natural History

Seals, walruses and sea lions all have flippers; a type of limb perfectly adapted for swimming and moving around in water. But how could a land living animal develop flippers? The adaptation evolved gradually over a long period of time, as some land living animals adapted semi-aquatic habits. New research now suggests that the genus Puijila is the “missing” evolutionary link between our modern seals, walruses and sea lions and their terrestrial ancestors.

Puijila darwini is described as having fore-limbs comparatively proportionate to modern carnivorous land animals rather than to pinnepeds*, a long tail, and webbed feet.

“The remarkably preserved skeleton of Puijila had heavy limbs, indicative of well developed muscles, and flattened phalanges which suggests that the feet were webbed, but not flippers. This animal was likely adept at both swimming and walking on land. For swimming it paddled with both front and hind limbs. Puijila is the evolutionary evidence we have been lacking for so long,” says Mary Dawson, curator emeritus of Carnegie Museum of Natural History.

The Puijila darwini skeleton was found in Nunavut, Canada in the remains of what was once a crater lake on coastal Devon Island. The first pieces of the skeleton were found in 2007, but the important basicranium wasn’t found until researchers paid a new visit to the site in 2008. Without a basicranium it is much more difficult to determine taxonomic relationships.

Based on Paleobotanic fossils, Devon Island had a cool, coastal temperate climate during the Miocene when Puijila darwini roamed the seashore. The conditions were quite similar to modern-day New Jersey and the lakes would freeze during the winter, something which probably prompted Puijila darwini to move over land from the lake to the sea in search of food.

“The find suggests that pinnipeds went through a freshwater phase in their evolution. It also provides us with a glimpse of what pinnipeds looked like before they had flippers,” says Natalia Rybczynski, leader of the field expedition.

The idea that semi-aquatic mammals may have undergone a transition from freshwater to saltwater is not new. In the On the Origin of Species by the Means of Natural Selection, Charles Darwin writes “A strictly terrestrial animal, by occasionally hunting for food in shallow water, then in streams or lakes, might at last be converted in an animal so thoroughly aquatic as to brace the open ocean.”

The oldest well-preserved pinniped animal belongs to the genus Enaliarctos and was a sea living creature with flippers. This species has been found on North Americas northern Pacific shores which have lead researchers to believe that the evolution of pinniped animals may have taken place mainly around the Arctic. This new finding of Puijila darwini strengthens that notion.

You can find more information about Puijila darwini and the origin of pinnipeds in the April 23 issue of the journal Nature.

http://www.nature.com

http://www.nature.com/nature/index.html

* The pinnipeds are a widely distributed and diverse group of semi-aquatic marine mammals. It contains the families Odobenidae (walruses), Otariidae (eared seals, including sea lions and fur seals), and Phocidae (earless seals). The name is derived from the Latin words pinna, which means wing or fin, and ped, which means foot. The pinnipeds are therefore also known as fin-footed mammals.

A federal judge on Wednesday refused to stop Oregon and Washington from trapping and killing California sea lions at Bonneville Dam this spring to keep them from gobbling endangered salmon.

The Humane Society of the United States filed a lawsuit against the plan and asked for a preliminary court injunction to stop it.

Humane Society attorneys argued that culling sea lions won’t significantly benefit threatened salmon and steelhead runs. Shooting the animals would harm Columbia River kayakers and others who have relationships with individual sea lions, they said

But U.S. District Judge Michael Mosman rejected the injunction request. The judge agreed that it appears somewhat arbitrary to crack down on sea lions when fishing kills more salmon listed under the Endangered Species Act. But initial evidence indicates that sea lions do “very serious” harm to endangered and threatened salmon, Mosman ruled.

“It’s a rather remarkable thing to say that (destroying) an individual animal will cause irreparable harm,” Mosman said early in the hearing. He later called the Humane Society’s evidence of damage “far less weighty” than the government’s.

State officials said they could begin trapping sea lions as early as Tuesday, targeting animals that have been seen eating federally protected fish at the dam.

The plan authorizes capturing and killing up to 85 sea lions a year for five years. But the states’ goal is to capture 30 this year, with first priority given to relocating the animals to captive environments such as Sea World and the St. Louis Zoo.

About 20 slots have been found so far, said Guy Norman, director of the Washington Department of Fish and Wildlife’s Vancouver office. Only about four weeks remain in the spring chinook’s journey upriver to Bonneville, Norman said.

“Our No. 1 step is to relocate as many sea lions as we can,” he said. “Whether we will get to lethal means this year is unknown.”

Anglers and biologists have grown increasingly frustrated with sea lions that feast on salmon gathering to climb Bonneville’s fish ladders. Last year, crews counted sea lions eating more than 4 percent of the salmon run, although biologists suspect they probably ate more.

Sea lion numbers have surged from about 1,000 animals in the 1930s to about 238,000 now along the West Coast. Fishery managers say it doesn’t make sense to let sea lions eat salmon while the Northwest restricts fishing and spends billions to try to help the fish recover.

Humane Society officials said the killing of sea lions at Bonneville Dam would be the first government-led killing since at least 1994, when Congress beefed up protection of marine mammals.

Other sea lions probably will take the place of the captured sea lions, they argued. Getting rid of 30 sea lions would save about 2,100 endangered or threatened fish, far fewer than fishing takes.

A decisive hearing on the lawsuit will be held as early as mid-May — when sea lion trapping probably will be finished for the year.

Sharon Young, a Humane Society field director, said the government should back off in the meantime. “We’re hoping they will not start shooting while the court is still hearing arguments.”

I have recieved permission to use this news article from Scott Learn at scottlearn@news.oregonian.com