March 19, 2013

Chesapeake Bay's intersex fish mystery remains unsolved and other wildlife disease news stories


First case of clinical CWD in a wild elk from Saskatchewan

The discovery on February 5th, 2013 of a dead yearling male elk in a farm yard near Nipawin, Saskatchewan marks the first wild elk to be found that has died of chronic wasting disease in the province. At autopsy this elk was thin and had an aspiration pneumonia which likely killed it. Aspiration pneumonia is a relatively common consequence of CWD....

This elk was discovered in Wildlife Management Zone (WMZ) 50, an area endemic for CWD. Submissions of deer and elk heads from hunters in this area have declined significantly over the last few years in spite of the presence of a free testing service; therefore, estimates of the prevalence of CWD in this zone are very crude.

A total of 53 cervids (deer and elk) have been tested from WMZ 50 over the last 3 years and of these 13 or 24% have tested positive. The 13 include a few deer that were found dead or sick and this is likely to bias the estimate. Although the prevalence appears to be very high, better surveillance is needed to estimate the true prevalence of the disease and the area over which these high prevalence’s are occurring.
15 Mar 2013
Location: Nipawin, Canada - Map It

Chesapeake Bay's intersex fish mystery remains unsolved

Ten years have gone by since one of the weirdest discoveries in the Chesapeake Bay region, on the south branch of the Potomac River -- male smallmouth bass with lady parts, eggs in places where they absolutely should not be.

Over that decade, wildlife biologists have probed the bay's tributaries, slicing open fish for more necropsies than anyone can count. And one thing is clear: They still aren't sure why between 50 and 100 percent of bass in various locations are gender-bending, switching from male to something called intersex.

Biologists say studies are falling short because of a lack of data on the type and quantity of pesticides that run into the bay from farms. This complaint, along with other factors, prompted Democrats in the Maryland House and Senate to sponsor two bills in the current legislative session that would for the first time require growers to record their use of insecticides and herbicides and submit it to the state.

The pesticide-reporting rule would create a treasure trove of data that scientists could draw from for studies on human and animal health, supporters say. Scientists could use it to focus research on chemical "hot spots," the exact moment high concentrations of pesticides hit waters where vulnerable young fish are growing, said Vicki Blazer, a biologist who studies bass for the U.S. Geological Survey.

Anchorage Daily News -
17 Mar 2013
D Fears
Location: Chesapeake Bay region, USA

Hundreds of Starving Baby Sea Lions Wash Ashore in Mysterious Mass Stranding

It began in January. At first, there were only a few. But as the weeks went on, more sea lion pups washed ashore. The dehydrated, emaciated pups showed up on Southern California's beaches, tucked under trucks and lifeguard towers....

In late January, scientists surveying Channel Island sea lion rookeries reported something worrying: Pups out there were in bad shape. By early February, regional marine mammal rescue centers were concerned. The strandings hadn't stopped. Instead, the pace was picking up.

Wired -
15 Mar 2013
N Drake
Location: Channel Islands, California, USA - Map It

Other Wildlife Health Related News
One Health News Corner
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