BY LARRY HAJNA
Wearing a headlamp and chest waders, state Department of Environmental Protection endangered species biologist Dave Golden walks carefully through a frigid pond in Cape May County on a nighttime search for salamanders and frogs.
It's an eerie, almost otherworldly scene as the beam from Golden's headlamp dances across the surface of the pond and trees along the pond's edges. Chorus frogs and spring peepers chirp raucously, apparently unfazed by Golden's presence.
Every now and then, Golden dips a net into the murky water, scooping up large tiger salamanders and tiny frogs that he takes to a clearing on the bank. There he swabs samples of their skin, especially the sensitive areas around their noses and underbellies, before returning the animals to the water.
Golden is looking for evidence of a potentially devastating disease known as a chytrid fungus that is threatening populations of amphibian species worldwide.
This spring, the DEP's Endangered and Nongame Species Program is teaming up with Montclair State University and the Conserve Wildlife Foundation of New Jersey in a project to determine if the disease is having any impact on New Jersey's frogs, toads and salamanders.
It is the first broad-based scientific study of chytrid fungus in New Jersey, where the greatest threats amphibians have faced to date have been habitat loss and being run over by vehicles.
"Our species are definitely susceptible to the disease; almost all amphibians are," Golden, a 10-year DEP veteran, said. "This is the first step. Right now we need to get information to see if it is a problem here. We need to establish baseline data."
Through May, the researchers will visit amphibian habitat in all 21 counties. Their goal is to collect at least 2,000 samples from all of New Jersey's 16 frog and toad species and at least four of the state's salamander species.
The project is funded by a grant from the federal State Wildlife Grants Program, the wildlife check off on state income tax returns, and sales and renewals of "Conserve Wildlife" license plates.
Montclair State and Conserve Wildlife are providing field staff to help with sampling. Montclair State is doing the laboratory analyses.
Several years ago, Kirsten Monsen-Collar and Lisa Hazard, assistant professors of biology at Montclair, took an interest in the possible impacts of the disease but realized there was no sampling data for New Jersey. They had found the fungus among amphibians at the New Jersey School of Conservation, a field station the university operates in Sussex County, and approached Golden about doing a statewide study.
"One possibility is that it's been here for a long time, that it has already done most of its damage, and what we're seeing now are resistant populations with a low level of infection," said Hazard. "Another possibility is that it arrived very recently and the effects are just now being felt. We just don't know."
Common in moist environments, chytrids are among the oldest and most primitive types of fungus known. In 1999, a new and potentially devastating type of chytrid was identified. It is spreading worldwide and may be capable of infecting most of the world's 6,000 amphibian species, according to Amphibian Ark, a partnership of zoological and conservation organizations.
The U.S. Fish and Wildlife Service cites this particular fungus as a major cause of amphibian mortality, and has proposed steps to try to halt its spread by banning the transportation of amphibians or their eggs across state lines unless they are certified as being free of the fungus. The disease has been spreading through the trade and importation of amphibians, some of which have been released into the wild.
The fungus feeds on keratin, the substance that makes the skin of frogs and salamanders tough and resilient. Researchers theorize that the fungus may produce toxins that are lethal to the animals or that infection thickens the skin to the point of no longer being able to absorb essential water and nutrients. There is no known effective treatment for populations affected in the wild. The only defense is quarantining infected populations.
"Understanding the prevalence of chytrid fungus in our amphibian population is an important first step in prioritizing our conservation efforts for amphibians, which are an important part of our ecology and biodiversity," David Jenkins, chief of the DEP's Endangered and Nongame Species Program, said.
The DEP tested eastern tiger salamanders in vernal ponds last year in conjunction with habitat restoration efforts and did not find evidence of the disease in this very rare species. Growing up to a foot long, the tiger salamander is New Jersey's largest salamander. It is found at fewer than 20 sites in the state, all in southern New Jersey and most of these in Cape May County.
"This species is already very rare," Golden said. "The disease, if it infected this species, could have a devastating impact."
The tiger salamander, named for the yellowish stripes running along the sides of its olive-green body, is the first amphibian species to emerge each year for mating, followed by peepers and chorus frogs. Mid-April will find the researchers testing pickerel frogs, green frogs and cricket frogs, among others.
In May, they will be sampling Pine Barrens tree frogs, southern gray tree frogs and bull frogs.
The state Division of Fish and Wildlife will submit a report of the project's findings to the U.S. Fish and Wildlife Service and post it online by the end of the year.
"It's hard to say right now what we'll be able to do if the disease is established in New Jersey," Golden said. "Are we going to see declines because of this disease? That's what we need to begin finding out."
For more information on the DEP's Endangered and Nongame Species Program, visit: http://www.nj.gov/dep/fgw/ensphome.htm