Initial Market Assessment of the Cultured, Non-native Oyster C. ariakensis

While biological risk assessments dominate the academic and political debate concerning the introduction of the non-native oyster (Crassostrea ariakensis) in Mid-Atlantic States, opportunity assessments of market potential are also needed. The successful introduction of a new species hinges in part on consumer and commercial quality evaluations compared to the established eastern oyster, Crassostrea virginica. A discriminatory taste test (triangle test) indicated with 99% confidence (B=.01, Pd=30%) the proportion of the population who can perceive a difference between the two species is between 0% and 32% for low salinity oysters, and between 8% and 51% for high salinity oysters. Three refrigerated storage (8°C) shellstock shelf life studies, conducted with both species from various grow out water temperatures (10°C, 17°C, and 26°C), consistently showed a significantly higher degree of mortality during refrigerated storage in C. ariakensis relative to C. virginica. As observed by accumulated drip, and confirmed by oyster meat moisture content analysis, substantial moisture is lost by C. ariakensis oysters (3.5% in low salinity oysters, 2% in high salinity oysters) within the first week of storage. Visceral desiccation in C. ariakensis was attributed to the lack of tight shell closure, with gaping occurring within 3 days of storage. Oyster condition index values were generally not a significant indicator of oyster quality during brief storage periods, though moisture monitoring may serve as a better indicator for shellstock shelf life. Microbial growth increased during storage for both species at both salinities, however, rate of increase was only significant for low salinity C. ariakensis. An incubation temperature of 25°C allowed for substantially higher aerobic plate count (APC) densities than at 35°C, indicating the potential for underestimating growth if the standard temperature (35°C) is used. Nutritional profile comparisons between the species illustrated similarities of proximate, lipid, and some mineral values. However, differences in key minerals and vitamins were observed, which may possibly affect sensory evaluations. Observed shell deformities located on the interior surfaces of the shells, ranging from blisters impacted with mud to calcareous knobs at the site of muscle attachment, pose marketing constraints for both species.