This program monitors Virginia waters for the presence of Pfiesteria species, Pfiesteria-like organisms, and Amphanomyces invadens and to examine patterns in the distribution and occurence of these organisms, fish lesions and fish kills.
VIMS was contracted beginning in 1998 by the Virginia Department of Health (VDH), with funding from the U. S. Centers for Disease Control and Prevention (CDC), to collect fish in Virginia waters for pathological examination of purported Pfiesteria-related lesions. Although the role that Pfiesteria species play in development of skin lesions in wild menhaden and other fishes is controversial, menhaden lesions are currently often used, in conjunction with assays for the presence of Pfiesteria-like cells in water samples and toxic fish bioassays, as a primary criterion for decisions about human health impacts and river closures in several mid-Atlantic states.
To devise a more sensitive, rapid, and specific approach for monitoring the activity of Pfiesteria and other potential pathogens in the environment, VIMS has developed molecular diagnostics for Pfiesteria piscicida, Pfiesteria shumwayae, other PLOs including Lucy-like and Cryptoperidiniopsis species (Reece et al. 2000, Vogelbein et al. 2001), and for Aphanomyces invadans. VIMS researchers used DNA sequences unique to each group of organisms to develop primers for use in the polymerase chain reaction (PCR) and DNA probes for in situ hybridization assays. These molecular tools have been used for monitoring in Virginia since August 2000. VIMS is currently using these molecular detection techniques to screen water samples collected by DEQ at Cohort sampling sites and Shellfish Sanitation stations, and by VIMS scientists in the Great Wicomico River. Several Virginia state agencies and cooperating research institutions [VIMS, ODU, VCU] have used presumptive counts and molecular-probe detection to generate datasets of environmental variables, lesion prevalence, presence or absence of Pfiesteria spp., Pfiesteria-like dinoflagellates and Aphanomyces invadans. VIMS researchers are currently analyzing available datasets for patterns in the distribution and occurrence of the potential pathogens, fish lesions, and fish kills.
Principal Investigator: Kimberly Reece