Performance of low-salinity genomically selected eastern oysters at two Louisiana grow-out sites

Eastern oyster (Crassostrea virginica) produced in a hatchery were maintained in cages at multiple sites in coastal Louisiana, and shell height, mortality, fecundity, and dermo were monitored to compare performance between genomically selected groups. Oysters were produced using genomic selection techniques targeting low-salinity tolerant oysters (high breeding value). To test performance among these groups in the field, oysters were deployed at two coastal Louisiana sites representing low and high salinity grow-out areas. From December 2024 through December 2025, a total of six replicate cages with n = 100 initial oysters from each of the three breeding groups (HBV, LBV, RC) were grown on long-lines at both sites with a randomized block design (total of 3200 oysters). Mortality and shell height were monitored monthly; condition index every other month; sex ration and histology and sex ration determined quarterly, and Perkinsus marinus infection levels estimated in October 2025. These data provide field performance data to assess performance of low-salinity tolerant selected oysters.