Previously posted by HerpDigest
HerpDigest
and
ProMED-mail <http://www.promedmail.org>
Date: Sat 24 Nov 2012 Source: Sunday Gazette-Mail [edited] <http://wvgazette.com/News/201211240036>
In July [2012], while walking near a small pond he had built on his
farm near Clendenin, Bill Archibald spotted a pair of dead eastern box
turtles in the brush.
"I didn't think a whole lot about it at first," Archibald recalled,
"but then I noticed other turtles in the same area acting kind of
lethargic, with swelling around their eyes, lying in the same spot for
days, and I started to wonder what was going on."
When Archibald returned to his farm following a weeklong trip to
Alaska, "every day that I walked up to the pond I'd find dead
turtles."
The mysterious deaths, which numbered 26 by the end of the summer,
didn't sit well with Archibald, a graduate of the state Division of
Natural Resources' Master Naturalist program, who had built the pond
to enhance habitat for the frogs, salamanders, and turtles living on
his land. He emailed Doug Wood, a retired Department of Environmental
Protection biologist who teaches several Master Naturalist classes.
"Bill sent me one of those unusual queries I get from time to time --
'Hey, Doug, do you know what this is?' " Wood recalled. After
consulting the Internet and some professional colleagues, Wood
supplied Archibald with the contact information he believed could
solve the mystery about what was killing the box turtles on his land.
As it turned out, the turtle was infected with ranavirus -- a pathogen
that causes an animal disease known to have caused large localized
die-offs, mainly in populations of frogs, salamanders, and other
amphibians in 25 states since 1997. In more recent years, the virus is
known to have infected scattered populations of box turtles, which are
reptiles, in several states.
At Wood's suggestion, Archibald got in touch with Towson University
(Maryland) biology professor Richard Siegel, leader of a box turtle
study at a highway construction site between Baltimore and Washington,
DC.
There, local turtles were outfitted with radio transmitters and
released in areas safe from blasting and heavy machinery. The study
was designed to determine whether relocated turtles did better by
being moved to a site 6 miles [9.7 km] from the construction zone, or
to an area just across a fence from the new highway site.
But Siegel and his Towson colleagues found that an alarming number of
turtles -- which can live to be 50 or older and normally have a 98
percent survival rate from year to year -- were dying at the
relocation area near the construction site. 31 of the 123 turtles
outfitted with the transmitters and released there were found dead
within a 3-year period. Cars or construction equipment killed 3 of the
turtles, but the rest were felled by disease, which turned out to be
ranavirus in 27 cases.
"Finding even one dead turtle is unusual," Siegel said in a Washington
Post story about the die-off that appeared earlier this year [2012].
"Finding over 27 dead turtles in a 2-to-3-year period was bizarre."
In addition to killing the Maryland box turtles, ranavirus is believed
to have been the cause of death of nearly every tadpole and young
salamander in the study area since spring of 2010.
Siegel referred Archibald, who had lost a similar number of turtles on
a half-acre [0.2 ha] tract of land within a single season, to Dr
Matthew Gray, professor of wetland ecology at the University of
Tennessee in Knoxville, and a ranavirus researcher. The Clendenin area
man sent 3 frozen box turtle carcasses to Gray for analysis through
the University of Tennessee's Center for Wildlife Health.
The best preserved of the 3 carcasses was that of a box turtle that
had exhibited signs similar to those shown by the ranavirus-infected
turtles in the Maryland study -- foot lesions, lethargy, difficulty
breathing, swollen eyes, and bubble production at the nose and mouth.
"We verified that ranavirus was the likely disease agent that killed
the turtles on Bill Archibald's property," said Gray. Of the 3 turtle
carcasses sent by Archibald, 2 were too decomposed for analysis, Gray
said. Because the 3rd carcass -- which tested positive for ranavirus,
had been frozen, damaging tissue cell structure -- a test could not be
made to confirm that ranavirus directly killed the turtle.
"We can say that the turtle from Bill Archibald's property was
infected with ranavirus, but without histology -- inspecting tissues
microscopically for damage by the pathogen -- we cannot make an
assessment if the infection caused the disease leading to death," Gray
said. "We plan to stay in contact with Bill, and will process
additional specimens if he observes mortality. Future plans are to
sequence a portion of the virus genome to determine if it is a common
or unique type of ranavirus."
Unlike the ranavirus incident in Maryland, frog and tadpole life in
and around Archibald's pond appears unaffected by the box turtle
die-off.
Researchers believe people, pets, farm animals, and warm-blooded
wildlife species are immune to ranavirus, because their bodies are too
warm to support the disease.
Wildlife biologists worry about how far ranavirus has spread, how fast
it is spreading, how often it recurs, and how quickly amphibians and
turtles can develop a resistance to it. Ranavirus-associated die-offs
involving more than 20 species of amphibians and turtles have been
recorded in at least 25 states since 1997.
The ranavirus outbreak that killed the Maryland box turtles was one of
the 1st known incidences involving that species. The National Wildlife
Health Center in Madison, Wisconsin, lists it as the nation's only
confirmed case of a ranaviral infection involving wild box turtles.
But the center acknowledges that similar ranaviral outbreaks in box
turtles have been reported in New York, Pennsylvania, Georgia, and
Florida, North Carolina, and Virginia prior to the case reported at
Archibald's farm.
"Ranavirus tends to hit amphibians in their young life stages, so when
it shows up, it can wipe out a whole age class," said Dr Anne Ballman,
wildlife disease specialist at the National Wildlife Health Center.
"If a local population runs out of young recruits, a species can be
wiped out for a season. If ranavirus occurs repeatedly, there is the
potential of that population declining dramatically in localized
areas."
Because there is no required monitoring of wildlife deaths due to
disease, it's difficult for wildlife biologists to know how
far-reaching and fast-moving the virus is.
"That's why it's important for people who come across large mortality
events involving amphibians or turtles to report them to their local
natural resource agency," Ballman said.
Researchers believe ranavirus is spread through direct contact with
infected animals, by exposure to contaminated water or sediment, or by
preying upon or cannibalizing animals carrying the virus.
"Observant folks who enjoy the woods, like Bill, are often the front
line of defense in documenting the spread of biological infestations
or infections," said Wood. Archibald's interest and action "led to
what appears to be the first known, or at least, first publicized
finding of ranavirus in a wild box turtle population in West Virginia.
This speaks highly of citizen involvement in conservation concerns."
"I wonder how the virus got here, whether it will come back again, and
why the frogs and tadpoles in the pond weren't affected by it," he
said. "I hope that by studying what happened here, researchers can
find some answers."
[Byline: Rick Steelhammer]
HerpDigest
and
ProMED-mail <http://www.promedmail.org>
Date: Sat 24 Nov 2012 Source: Sunday Gazette-Mail [edited] <http://wvgazette.com/News/201211240036>
In July [2012], while walking near a small pond he had built on his
farm near Clendenin, Bill Archibald spotted a pair of dead eastern box
turtles in the brush.
"I didn't think a whole lot about it at first," Archibald recalled,
"but then I noticed other turtles in the same area acting kind of
lethargic, with swelling around their eyes, lying in the same spot for
days, and I started to wonder what was going on."
When Archibald returned to his farm following a weeklong trip to
Alaska, "every day that I walked up to the pond I'd find dead
turtles."
The mysterious deaths, which numbered 26 by the end of the summer,
didn't sit well with Archibald, a graduate of the state Division of
Natural Resources' Master Naturalist program, who had built the pond
to enhance habitat for the frogs, salamanders, and turtles living on
his land. He emailed Doug Wood, a retired Department of Environmental
Protection biologist who teaches several Master Naturalist classes.
"Bill sent me one of those unusual queries I get from time to time --
'Hey, Doug, do you know what this is?' " Wood recalled. After
consulting the Internet and some professional colleagues, Wood
supplied Archibald with the contact information he believed could
solve the mystery about what was killing the box turtles on his land.
As it turned out, the turtle was infected with ranavirus -- a pathogen
that causes an animal disease known to have caused large localized
die-offs, mainly in populations of frogs, salamanders, and other
amphibians in 25 states since 1997. In more recent years, the virus is
known to have infected scattered populations of box turtles, which are
reptiles, in several states.
At Wood's suggestion, Archibald got in touch with Towson University
(Maryland) biology professor Richard Siegel, leader of a box turtle
study at a highway construction site between Baltimore and Washington,
DC.
There, local turtles were outfitted with radio transmitters and
released in areas safe from blasting and heavy machinery. The study
was designed to determine whether relocated turtles did better by
being moved to a site 6 miles [9.7 km] from the construction zone, or
to an area just across a fence from the new highway site.
But Siegel and his Towson colleagues found that an alarming number of
turtles -- which can live to be 50 or older and normally have a 98
percent survival rate from year to year -- were dying at the
relocation area near the construction site. 31 of the 123 turtles
outfitted with the transmitters and released there were found dead
within a 3-year period. Cars or construction equipment killed 3 of the
turtles, but the rest were felled by disease, which turned out to be
ranavirus in 27 cases.
"Finding even one dead turtle is unusual," Siegel said in a Washington
Post story about the die-off that appeared earlier this year [2012].
"Finding over 27 dead turtles in a 2-to-3-year period was bizarre."
In addition to killing the Maryland box turtles, ranavirus is believed
to have been the cause of death of nearly every tadpole and young
salamander in the study area since spring of 2010.
Siegel referred Archibald, who had lost a similar number of turtles on
a half-acre [0.2 ha] tract of land within a single season, to Dr
Matthew Gray, professor of wetland ecology at the University of
Tennessee in Knoxville, and a ranavirus researcher. The Clendenin area
man sent 3 frozen box turtle carcasses to Gray for analysis through
the University of Tennessee's Center for Wildlife Health.
The best preserved of the 3 carcasses was that of a box turtle that
had exhibited signs similar to those shown by the ranavirus-infected
turtles in the Maryland study -- foot lesions, lethargy, difficulty
breathing, swollen eyes, and bubble production at the nose and mouth.
"We verified that ranavirus was the likely disease agent that killed
the turtles on Bill Archibald's property," said Gray. Of the 3 turtle
carcasses sent by Archibald, 2 were too decomposed for analysis, Gray
said. Because the 3rd carcass -- which tested positive for ranavirus,
had been frozen, damaging tissue cell structure -- a test could not be
made to confirm that ranavirus directly killed the turtle.
"We can say that the turtle from Bill Archibald's property was
infected with ranavirus, but without histology -- inspecting tissues
microscopically for damage by the pathogen -- we cannot make an
assessment if the infection caused the disease leading to death," Gray
said. "We plan to stay in contact with Bill, and will process
additional specimens if he observes mortality. Future plans are to
sequence a portion of the virus genome to determine if it is a common
or unique type of ranavirus."
Unlike the ranavirus incident in Maryland, frog and tadpole life in
and around Archibald's pond appears unaffected by the box turtle
die-off.
Researchers believe people, pets, farm animals, and warm-blooded
wildlife species are immune to ranavirus, because their bodies are too
warm to support the disease.
Wildlife biologists worry about how far ranavirus has spread, how fast
it is spreading, how often it recurs, and how quickly amphibians and
turtles can develop a resistance to it. Ranavirus-associated die-offs
involving more than 20 species of amphibians and turtles have been
recorded in at least 25 states since 1997.
The ranavirus outbreak that killed the Maryland box turtles was one of
the 1st known incidences involving that species. The National Wildlife
Health Center in Madison, Wisconsin, lists it as the nation's only
confirmed case of a ranaviral infection involving wild box turtles.
But the center acknowledges that similar ranaviral outbreaks in box
turtles have been reported in New York, Pennsylvania, Georgia, and
Florida, North Carolina, and Virginia prior to the case reported at
Archibald's farm.
"Ranavirus tends to hit amphibians in their young life stages, so when
it shows up, it can wipe out a whole age class," said Dr Anne Ballman,
wildlife disease specialist at the National Wildlife Health Center.
"If a local population runs out of young recruits, a species can be
wiped out for a season. If ranavirus occurs repeatedly, there is the
potential of that population declining dramatically in localized
areas."
Because there is no required monitoring of wildlife deaths due to
disease, it's difficult for wildlife biologists to know how
far-reaching and fast-moving the virus is.
"That's why it's important for people who come across large mortality
events involving amphibians or turtles to report them to their local
natural resource agency," Ballman said.
Researchers believe ranavirus is spread through direct contact with
infected animals, by exposure to contaminated water or sediment, or by
preying upon or cannibalizing animals carrying the virus.
"Observant folks who enjoy the woods, like Bill, are often the front
line of defense in documenting the spread of biological infestations
or infections," said Wood. Archibald's interest and action "led to
what appears to be the first known, or at least, first publicized
finding of ranavirus in a wild box turtle population in West Virginia.
This speaks highly of citizen involvement in conservation concerns."
"I wonder how the virus got here, whether it will come back again, and
why the frogs and tadpoles in the pond weren't affected by it," he
said. "I hope that by studying what happened here, researchers can
find some answers."
[Byline: Rick Steelhammer]