Detecting the Extent of Mortality Events from Ranavirus in Amphibians of the Northeastern U.S.

In order to better understand the extent to which Ranavirus is impacting amphibian and reptile populations in the Northeast region of the U.S. and to develop and test a sampling protocol that could be used throughout the region, we conducted a survey of amphibian larvae at 122 randomly-selected wood frog (Lithobates sylvaticus) breeding ponds in a 142,286 km2 study area encompassing parts of Delaware, Maryland, New Jersey, Pennsylvania, and Virginia. In 2013 and 2014, a total of 4,306 individual wood frog larvae (30 larvae per pond) were collected for quantitative PCR (qPCR) analysis by Montclair State University (New Jersey). Additionally, 158 individuals of seven amphibian species potentially involved in active die-offs were collected for analysis by the U.S. Geological Survey (USGS) National Wildlife Health Center (NWHC). This study represents both the largest geographic area and the greatest sample size ever screened for Ranavirus.