MORTALITY AND REOVIRUS INFECTION IN SOFT-SHELL BLUE CRAB (CALLINECTES SAPIDUS) AQUACULTURE

Abstract

Soft-shell blue crab production the United States is an undervalued aquaculture practice experiencing high crab mortality rates from a series of stressors, including disease. The impact of one disease, the reovirus CsRV1, remains unquantified in major soft-shell crab production regions, despite the virus’ known ubiquity and lethality. My research examined the mortality and CsRV1 infection rates of pre- and post-production crabs in Maryland, Virginia, and Louisiana soft-shell crab production facilities in 2016-2017, attempting to link these rates to water quality and aquaculture practice variables. I found that recirculating aquaculture systems lost half the proportion of crabs (16%) that flow-through systems did (33%). CsRV1 infection was the primary predictor of crab death in Chesapeake aquaculture, presenting in 75% of dead crabs compared to 22% of dead crabs in Louisiana aquaculture. Multi-state data suggests crab losses worth over $2 million are attributable to CsRV1, indicating a need for aquaculture effluent and discard control.