Cool and coldwater aquaculture research

Sturgeon TranscriptomicsSince the highest value in products from farmed sturgeon resides in the caviar, a significant benefit could be derived from being able to predict which females are most likely to mature at a younger age, and to concentrate culture efforts and resources on production of these animals. Caviar quality (e.g., size, firmness, color and flavor) also plays a major role in determining the market value of this product. The ability to predict the quality of caviar produced by individual females, or to have an 'early warning system' for detection of potentially poor quality product, would be an invaluable asset for inventory management and quality control on sturgeon farms. If a tool or suite of measurements could be developed to help make predictions regarding age at maturation and caviar quality, this would be extremely valuable to sturgeon farmers in NC and elsewhere. Use of such tools could also improve identification of superior fish for selective breeding purposes. We can approach all of these outcomes by probing the relationships between gonadal gene expression (transcription) and fish gender, maturity status, and caviar quality.A Survey of Weissella sp. in North CarolinaRecent published reports indicate that novel Weissella sp. bacteria were associated with disease outbreaks in rainbow trout (Oncorhynchus mykiss) at trout farms in China and Brazil. These were the only reports of trout disease from these bacteria anywhere in the world until now. In 2011 a disease outbreak occurred at a rainbow trout farm in western North Carolina, displaying clinical signs similar to those reported in China and Brazil. Bacteria isolated from moribund fish were identified to the genus level as Weissella sp. by gene sequence analysis and were 99% identical to the sequences of isolates collected from the Chinese and Brazilian outbreaks. Laboratory challenges conducted at the National Center for Cool and Coldwater Aquaculture (NCCCWA) with the isolated pathogen replicated both the disease signs and mortality in exposed healthy rainbow trout. In 2012, Weissella sp. was again isolated from moribund fish in NC, demonstrating a capacity to sustain within the fish population on the farms. These bacteria have not yet been found in other areas of NC (or the US). Also in 2012 a custom vaccine formulation was shown to confer significant protection against experimental Weissella infection in laboratory challenges at NCCCWA. Beginning in spring of 2012, the NC trout industry included vaccination against Weissella sp. in their routine practices. The original farm where the outbreak first occurred has now vaccinated all the fish on their facility. The purpose of this research is to determine whether this pathogen can be detected on the original farm and on farms in the surrounding area, and to determine whether the concerted vaccination effort could potentially eliminate it from all farms in the region.