ASSESSING AND MANAGING RISK OF PATHOGEN CONTAMINATION OF OYSTER SEED DURING PRODUCTION AND IMPORTATION

The goal of this study is to generate evidence-based knowledge on the potential risk of spread of pathogenic V. parahaemolyticus associated with contaminated oyster seed and evaluate the utility of potential remedies. One potential remedy is to 'relay' the seed oyster, to an area with higher salinity for two weeks, before transporting the seed oyster to the farm site (estuarine embayment). We actually will employ this process in theory for shellfish from approved areas (not restricted areas) but where shellfish may still be contaminated. The relay practice for harvested oystershas been called "transplantation" but is not currently regulated. We hypothesize that oyster seed is vulnerable to colonization by V. parahaemolyticus. We further hypothesize that destabilization of the normal microbiota through "relay" can reduce V. parahaemolyticus levels. To address these hypotheses, we will implement several applied research objectives includingObjective 1: Assess the risk associated with oyster seed importation through enumeration of total and pathogenic V. parahaemolyticus of oyster seed from both approved and unpermitted locations.Objective 2: Evaluate the extent that "relay" or transplantation changes the microbial composition and V. parahaemolyticus levels.Objective 3: Modify and improve existing enumeration (quantification) methods to increase fidelity and accuracy for pathogenic V. parahaemolyticus.These objectives were developed with the direct input of both oyster growers and managers in New Hampshire and identified as priority areas for an applied research component of this project. We expect that the knowledge generated by the project will inform the oyster seed importation permit process to expand importation options as a contingency if pathogentic V. parahaemolyticus ST36 strain further spreads and limit the risk of introduction of other emergent strains.