BAIT SHOPS AN ENVIRONMENTAL THREAT?
April 12, 2009
of the spring fishing season brings amphibian diseases, according to a
press release issued this week by the National Science Foundation (NSF).
"Infectious diseases are affecting populations of amphibians, from
frogs to salamanders," states the release, and "biologists have
discovered that amphibian diseases are spread by bait shops."
is based on scientific research by the well-known amphibian biologist
James Collins, assistant director for biological sciences at NSF. The
article, coauthored with Angela Picco of the U.S. Fish and Wildlife Service,
appeared in the internationally respected journal "Conservation Biology."
are indisputable: Some bait shops sell salamanders carrying pathogens
that are "disease-causing agents such as some viruses and bacteria,"
and these diseases can infect other amphibians. Two primary pathogens
are implicated in the study. One is a chytrid fungus with the scientific
name Batrachochytrium dendrobatidis, commonly referred to as Bd.
The other is a group known as ranaviruses. Diseases caused by the pathogens
have been implicated in the decline--and in some cases extinction--of
conducted in several western states where tiger salamander larvae are
sold as live fish bait for a variety of game fish, is applicable to the
southeastern states as well. For example, so-called spring lizards that
are sold for bait in some areas are simply aquatic salamanders that presumably
can be infected as well. Bd has even been discovered in frogs in the Congaree
National Park in South Carolina.
of the study, Collins and Picco "organized bait-shop surveys to determine
whether tiger salamanders are released back into the wild after being
housed in shops." They found that 26 to 73 percent of anglers in
the study area used "tiger salamanders as bait; 26 to 67 percent
of anglers released tiger salamanders bought as bait into fishing waters;
and four percent of bait shops put salamanders back in the wild"
after they had been kept in containers with infected animals. Both pathogens
are contagious among amphibians.
finding was that all of the salamanders sold in the bait trade had been
collected in the wild and not produced through some form of aquaculture
or captive breeding. If salamanders are being removed from the wild on
a regular basis, natural populations are being depleted. Also, the salamanders
are moved indiscriminately from one region to another, "bringing
with them multiple ranavirus strains."
we can all think of instances when diseases were unintentionally introduced
into other regions, with detrimental results to the environment. Two of
the better known are the devastation to American chestnuts caused by the
chestnut blight that resulted from the planting of Japanese chestnuts
and the importation of infected timber that spread Dutch elm disease across
North America. What will the consequences be if ranaviruses and Bd begin
to eliminate amphibian species throughout the country because of diseases
spread by fish bait? Amphibians are an integral and functional part of
the ecosystems they inhabit. Many are significant in natural food webs,
and their disappearance would be a major loss to our natural heritage.
and recreational impact of tighter regulation and control on the use of
wild-caught salamanders as fish bait must be weighed against the environmental
gain achieved by not exacerbating the documented decline of natural populations
of amphibians. To get an idea of how many bait shops are in different
states, check out the Web site www.baitnet.com.
A lot of them are out there. However, presumably a near infinitesimally
small proportion of Americans make their living selling salamanders, so
economic impacts of not using salamanders as fish bait would be minimal.
And countless other forms of bait are available for use by anglers, no
matter what they are fishing for. So a quick cost-benefit analysis indicates
that the environmental benefits of not using salamanders as fish bait
far outweigh any economic or recreational costs.
shops can come up with a surefire way to guarantee that diseased salamanders
are not distributed into areas where other amphibians can become infected,
maybe anglers should just stop using tiger salamanders and spring lizards
when they go fishing. People, including other anglers, who enjoy natural
habitats where amphibians abound will appreciate it.
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