The news release and pictures are at this website:
http://www.usgs.gov/newsroom/article.asp?ID=2268&from=rss_home
USGS News Release
| Aug. 3, 2009 | Catherine Puckett (call during WDA conference) | 352-264-3532 | cpuckett@xxxxxxxx |
New Ouchless Plague Vaccine, Shipwrecks Wrecking Coral Reefs, White-Nose Syndrome in Bats, and More at the Wildlife Disease Association Conference
Note to reporters and editors: The 58th annual meeting of the Wildlife Disease Association (WDA) will be August 2-7, 2009, in Blaine, Wash. The theme is Wildlife Health from Land to Sea: Impacts of a Changing World. This release is based on USGS research being presented at the conference. Also see a full press release on emerging diseases in fish at http://www.usgs.gov/newsroom/)
Get Your Shots! Eating Ouchless Vaccines Protects Prairie Dogs in the Lab Against Plague: A new oral vaccine against sylvatic plague is showing significant promise in the laboratory as a way to protect prairie dogs and may eventually protect endangered black-footed ferrets who now get the disease by eating infected prairie dogs, according to results by a USGS researcher at the USGS National Wildlife Health Center. Sylvatic plague is an infectious bacterial disease usually transmitted from animal to animal by fleas. This exotic disease is usually deadly for black-footed ferrets and their primary prey, prairie dogs, resulting in local extinctions or regional population reductions. Along with other wild rodents, prairie dogs are also considered a significant reservoir of plague for other wildlife, domestic animals, and people in the western U.S. Prevention of plague in wild rodents by immunization could reduce outbreaks of the disease in animals, thereby reducing the risk for human exposure to the disease.
USGS scientists offered plague vaccine in food for voluntary consumption by 16 black-tailed prairie dogs. They also injected a plague vaccine into 12 other prairie dogs and then studied how much protection against plague the two kinds of vaccines offered. USGS researcher Dr. Tonie Rocke, the lead researcher of the project, found that the prairie dogs that “ate” their vaccine were better protected from the disease than the ones who were injected with a vaccine. These results, said Rocke, demonstrate that oral immunization of prairie dogs against plague provides significant protection from the disease, at least in the laboratory. Black-footed ferrets, of course, are one of the rarest mammals in North America. An oral vaccine, said Rocke, could be put into bait and delivered into the field without having to handle any animals, a process that is time-consuming, costly, and sometimes stressful for the animals. The same bacterium that affects ferrets, prairie dogs, and other rodents, is also responsible for human cases of plague. For more information, contact Dr. Tonie Rocke at 608-270-2451 or trocke@xxxxxxxx
Shipwrecks Wrecking Coral Reefs?
A Case Study at Palmyra Atoll National Wildlife Refuge:
For the first time, researchers
have definitively shown that shipwrecks and other man-made structures increase
the potential for large invasions of unwanted species into coral reefs,
even comparatively pristine ones. These unwanted species can completely
overtake a reef and eliminate native corals, dramatically decreasing the
diversity of marine organisms on the reef. Coral reefs can undergo fast
changes in their dominant life forms, a phenomenon referred to as phase
shift. Scientists have speculated on many possible causes of phase shift,
but this study is the first one to clearly show that a rapid change in
the dominant life forms on a coral reef is associated with man-made structures.
In September 2007, USGS researcher
Dr. Thierry Work, Dr. Greta Aeby from the Hawaii Institute of Marine Biology,
and Dr. James Maragos from U.S. Fish and Wildlife Service studied
a 100-foot vessel that wrecked in 1991 on isolated Palmyra Atoll in the
central Pacific Ocean. They found extremely high numbers of an invasive
species related to anemones and corals, Rhodactis howesii, on and
around the shipwreck site. The density of this species progressively decreased
with distance from the ship, and it was rare or absent in other parts of
the atoll. Likewise, the researchers confirmed high densities of R.
howesii around several buoys installed on the atoll in 2001.
Even though phase shifts can have
long-term negative effects for coral reefs, eliminating organisms responsible
for phase shifts can be difficult, particularly if they cover a large area.
The extensive R. howesii invasion and subsequent loss of coral reef
habitat at Palmyra highlights the importance of rapid removal of shipwrecks
on corals reefs to help prevent reefs from being overgrown by invasive
species.
"Why this phenomenon is occurring
remains a mystery," said Work, a scientist at the USGS National Wildlife
Health Center's Honolulu Field Station. One possibility, he said, is that
iron leaching from the ship and mooring buoy chains, accompanied with other
environmental factors particular to Palmyra Atoll, are somehow promoting
the growth of Rhodactis. For more information, contact Dr. Thierry
Work at 808-72-9250 or thierry_work@xxxxxxxx
Society, Wildlife Disease and
Wildlife Conservation: Oxymoron or Evolutionary Siblings? Over the
past 50 years, the field of wildlife disease as an issue for concern has
exploded in significance, mostly because of the increased realization that
most emerging human diseases are “zoonotic,” that is, diseases that can
spread from people to other animals or vice-versa. USGS emeritus scientist
Dr. Milt Friend, in an invited talk at the Wildlife Disease Association
conference, will explore how and why the field of wildlife disease research
has changed over the last 50 years.
One of the biggest differences,
says Friend, is that until very recently, wildlife disease was not an important
focus for the wildlife conservation community. “Now, though, a new wave
of social environmentalism and public concerns about emerging zoonotic
diseases are placing increased pressure on wildlife agencies to address
disease ‘crises’ involving wildlife,” Friend says.
He emphasizes, however, that emerging
zoonotic diseases often result in double jeopardy for wildlife: not only
do wildlife often suffer direct negative effects from a disease, they also
endure indirect effects associated with actions taken to reduce human risks
by suppressing wildlife populations. In addition, says Friend, wildlife
can also be jeopardized by actions taken if they happen to share diseases
with domestic animals, even if those diseases do not pose a significant
public health threat. “Conversely, within the wildlife conservation community,
the role of disease as a factor for species extinctions is receiving increased
worldwide attention,” Friend noted. For more information, contact Dr.
Milton Friend at 608-270-2488 or mfriend@xxxxxxxx
Disease Risks When Moving Wildlife
to New Areas: Endangered Laysan Duck Cautionary Tale:
Laysan ducks, one of the world's
most endangered waterfowl, are native to only the Hawaiian archipelago.
For 150 years, Laysan ducks were restricted to an estimated 4 square kilometers
of land on Laysan Island in the northwestern Hawaiian Islands. In 2004
and 2005, in an effort to rebuild the
population, biologists released 42 Laysan ducks on Midway Atoll, located
one day's boat ride from Laysan. By 2007, a breeding population was well
established on Midway, reaching 200 ducks. However, in August 2008, more
than half of the Midway duck population (181 ducks) was lost to a disease
epidemic lasting 30 days. Necropsies (the animal equivalent of autopsies)
on dead birds revealed botulism type C as a cause of the die-off.
Disturbingly, said Work,
3 ducks were also infected with a worm suspected to be Echinuria uncinata;
this worm has been responsible for mass die-offs of Laysan ducks on Laysan
Island. Work notes that this worm was either moved to Midway during translocations
of ducks from Laysan, despite preventive treatment of all founding birds,
or it arrived with migratory waterfowl. Either way, says Work, this epizootic
highlights the disease risk to birds restricted to small island populations
and the challenges associated with managing newly translocated endangered
species. Frequent population monitoring for early disease detection
and comprehensive wetland monitoring and management will be needed to offset
the potential effects of avian botulism and parasitism on endangered Laysan
ducks, Work said. The bigger picture, though, is that disease risks need
to be closely examined for translocations of all kinds, especially in light
of translocations being proposed for dealing with habitat range changes
that affect endangered species due to climate change. For more information,
contact Dr. Thierry Work at 808-72-9250 or thierry_work@xxxxxxxx
Bat white-nose syndrome: An
emerging fungal pathogen? New research provides even more evidence
that a previously undescribed, cold-loving fungus is associated with white-nose
syndrome, a condition linked to the deaths of up to 1,000,000 cave-hibernating
bats in the northeastern and mid-Atlantic states. Since the winter of 2006-2007,
bat populations plummeted from 80 to 97 percent at surveyed bat-hibernation
caves, called hibernacula. USGS microbiologist Dr. David Blehert and his
colleagues identified the fungus last year, and have followed up by trying
to determine if the fungus may be responsible for the deaths or if it is
simply a side effect of another underlying disease. The researchers
found that 90 percent of all bats they examined from suspected WNS sites
had a severe fungal skin infection that did not just occur on the skin,
but below it as well. The growth temperature requirements of the fungus
are consistent with the core temperatures of cave-hibernating bat species
throughout temperate regions of the world. Given the hundreds of thousands
of hibernating bats found throughout the WNS-affected region, as well as
the potential for the spread of this disease to other parts of the United
States and Canada, white-nose syndrome represents an unprecedented threat
to bats of the northeastern United States and potentially beyond. For
more information, contact Dr. David Blehert at 608-270-2466 or dblehert@xxxxxxxx
Sick Fish May Get Sicker: Climate
Change and Other Stresses Expected to Affect Entire Populations of Fish
(see full press release on this subject at http://www.usgs.gov/newsroom/)
Entire populations of North American
fish already are being affected by several emerging diseases, a problem
that threatens to increase in the future with climate change and other
stresses on aquatic ecosystems, according to a noted U.S. Geological Survey
researcher giving an invited talk on this subject today at the Wildlife
Disease Association conference in Blaine, Wash.
“A generation ago, we couldn’t
have imaged the explosive growth in disease issues facing many of our wild
fish populations,” said Dr. Jim Winton, a fish disease specialist at the
USGS Western Fisheries Research Center. “Most fish health research
at that time was directed toward diseases of farmed fish.” In contrast,
said Winton, recent studies in natural aquatic systems have revealed that,
in addition to being a cause of natural death, infectious and parasitic
fish diseases can produce significantly greater mortality in altered habitats
leading to population fluctuations, extinction of endangered fish, reduced
overall health and increased susceptibility to predation. For more information,
contact Dr. Jim Winton at 206-526-6282, x328 or jwinton@xxxxxxxx
USGS provides science for a changing
world. For more information visit www.usgs.gov.
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Catherine Puckett
USGS Office of Communications
2201 NW 40th Terrace
Gainesville, FL 32605-3574
OFFICE PHONE: 352-264-3532
CELL PHONE: 352-275-2639
FAX: 352-374-8080
EMAIL: cpuckett@xxxxxxxx
