MODELING RAPID CHILLING OF EASTERN OYSTERS Crassostrea virginica

Eastern Oysters (Crassostrea virginica) are naturally occurring shellfish along the east coast of Canada and the United States and into the Gulf of Mexico. The oysters are harvested for consumption throughout the year leading to high rates of seafood-borne illnesses when the water temperatures rise and bacteria flourish. Vibrio vulnificus and Vibro parahaemolyticus are the leading causes of seafood-borne bacterial illness due to the consumption of raw shellfish. The frequency of illnesses increase along with the water temperature. Regulations are in place to combat the increase of bacteria creating strict time/temperature requirements for harvesting oysters in the summer months. Alternatives have arisen to increase the time from harvest to mechanical refrigeration by way of chilling the oysters using an ice-slurry. These alternatives could be more effective with more information on the thermodynamics of oysters and modeling.

The modeling of oyster thermodynamics takes into account different parameters and chilling techniques. The wide expanse of locations from Canada to the Gulf Coast give a range of temperatures and conditions the oysters can be harvest from resulting in different exposure times to the chilling requirements. This model would allow location specific requirements to adjust chilling times. Oysters are also harvested in different ways depending on the region, some harvesters dredge the area and extract hundreds of oysters at a time while others cultivate oysters in bags. The model can be adjusted depending on the volume of oysters needing to be chilled. This would allow for a more comprehensive chilling of all oysters to reduce the risk of seafood-borne bacterial illness.

This presentation encompasses the varying conditions of oyster harvesting and treatment to help prevent illness from the consumption of seafood. This work can be implemented into current practices of oyster chilling to ensure temperature requirements are met. This model can also be modified to incorporate other aquaculture products as the industry continues to grow.