Summer 2012 Newsletter

Our initial research problem was to understand the prevalence and intensity of the water-borne fungus Batrachochytrium dendrobatidis (Bd) in New Jersey amphibians. The objectives related to addressing this problem were twofold. The first objective was to correlate water and air temperature to the prevalence and intensity of Bd. Other studies in the field and in the lab have shown that Bd is sensitive to both water and air temperature. No such study has been done in New Jersey. Our lab is the first lab to document Bd in the state (Monsen-Collar et al., 2010), and preliminary results show that Bd prevalence may be higher during cooler months. The second objective was to relate biotic factors to prevalence and intensity of Bd. I anticipated species-specific responses to Bd, with some species exhibiting more susceptibility to both infection and disease symptoms. Areas with significant populations of Bdresistant organisms, such as bullfrogs and tiger salamanders, would have a higher prevalence of Bd. While sampling for Bd and not finding any amphibians exhibiting symptoms of even a mild Bd infection, we were alerted to the presence of great quantities of dead tadpoles in Ocean County, NJ; tadpoles exhibited symptoms consistent with a Ranavirus disease. The site is being managed by Herpetological Associates, Inc. (Executive Director, Robert T. Zappalorti) for the endangered pine snake (Pituophis melanoleucus), and also harbors a population of Pine Barrens Treefrog (Hyla andersonii). The Ranavirus disease is even more lethal than that caused by the Bd fungus, typically killing amphibians within a few days to a week of infection (Harp and Patrenka, 2006). The presence of Ranavirus had never been documented in New Jersey prior to this occasion, and so we decided to focus our efforts on confirming, via molecular analyses, that the diseased tadpoles were indeed infected with Ranavirus and tracking the spread of the disease throughout the state. Animals were sampled from five ponds located in the vicinity of the Stafford Business Park, in Ocean County, NJ, within an area that is being managed for the benefit of pine snake populations. Because of the mass mortality and severity of the disease outbreak, samples were collected from throughout the state and tested for Ranavirus in much the same way samples were collected from Ocean County. Other sites included Assunpink Wildlife Management Area, Green Creek and Lizard Tail Swamp (Middle Township), Tuckahoe pond (Upper Township), Great Swamp National Wildlife Refuge, Berkshire Valley Wildlife Management Area, Wanaque Wildlife Management Area, Weiss Ecology Center, Norvin Green State Forest and the NJ School of Conservation. Sites were visited multiple times. Tadpoles at the Ocean County site displayed signs of Ranaviral Researchers Report First Known Cases of Ranavirus in New Jersey