A Clockwork Naturalist

Credit: Photo courtesy of Taylor Edwards, 2010, via ScienceDaily

June 29, 2011 - A team of researchers investigated a desert tortoise from the United States Southwest and northwestern Mexico. What was thought to be a simple problem in species identification turned out to be a very complex matter. Their investigations required forensic genetics and several other methods. In the end, they found it necessary to describe a new species. More than that, the discovery has very important implications for conservation and the development of the deserts of southern California. [full story]

Other areas of California are now reporting numbers of dead leopard sharks - the still-mysterious affliction would seem to be the same one observed in the sharks of Redwood City, (see my initial post on this issue).

By Mark Prado, The Marin Independent Journal, 5/19/2011:

…Starting May 2, Richardson Bay Audubon Center and Sanctuary researchers began to scour beaches along Richardson Bay after high tide. Since then, more than 20 have turned up dead.

“The leopard sharks are here this time of year anyway, but we don’t know if that’s why we are seeing dead ones or if they are being washed here,” Wilcox said. “There are all sorts of questions.”

Last week, Liz Beers and her mother were walking near Greenwood Cove near the Cove Apartments in Tiburon and saw five leopard sharks that had beached themselves.

“Three of the leopard sharks were already dead and the other two were floundering about, trying to free themselves from the mud,” she wrote via email. “It was a very sad sight.”

More than 100 of the sharks have washed ashore in San Mateo, San Francisco and Marin counties over the past month.

The sharks need a certain amount of salinity to survive, but with all the rain that has fallen this year there may be too much freshwater in the bay. A similar die-off occurred in 2006 after heavy rains, said Carrie Wilson, biologist with the state Department of Fish and Game.

“Based on history, that is one thing we are looking at,” she said.

But the evidence for that theory is not conclusive. Another theory is that there is a lack of oxygen in the water. Samples of the dead sharks have been taken for analysis. Those results will come back in a few weeks and could provide more details. [full story]

SEEN A SHARK?

Workers at the Richardson Bay Audubon Center are asking the public to notify them with any sightings of dead or dying leopard sharks. Email kwilcox@audubon.org or call 388-2524.

This story has me really, really upset, so I’m going to be following it closely and posting updates about it whenever I can. Here’s a more detailed article from X-Ray Mag. See if you can spot the red flag in this description of the behavior of the species.

“The leopard shark occurs in the cool to warm-temperate continental waters of the northeastern Pacific Ocean, from Coos Bay, Oregon to Mazatlán, Mexico, including the Gulf of California. It favors muddy or sandy flats within enclosed bays and estuaries, and may also be encountered near kelp beds and rocky reefs, or along the open coast. Numbers have been known to gather near discharges of warm effluent from power plants.”

Wow, what an interesting friggin’ coincidence. [full story]

The poor little guys.

Photo credit: Matthew Field, www.photography.mattfield.com

Discovery News - Analysis by Jennifer Viegas

Thu May 12, 2011 01:28 PM ET

Dozens of leopard sharks have been washing up dead in California since April, and now a necropsy shows at least one of the sharks died of massive internal bleeding, such that blood was even coming out of the shark’s skin, according to a Daily News report…

…A key question then clearly remains: What is causing the internal bleeding?

As of now, that’s still a mystery. A statement released by the Silicon Valley city mentioned, “The…pathologist is not drawing any conclusions until more examinations and all tests are performed.” [full story]

(Photo credit: Upsilon Andromidae)