Marine Finfish Aquaculture in North Carolina: Current Research and Commercial Pilot Initiatives.
Presentation
Overview
Overview
Description
In NC, leading marine finfish species for intensive aquaculture are the southern flounder (SF, Paralichthys lethostigma) and the black sea bass (BSB, Centropristis striata). These high value, commercially important species can potentially be cultivated in inland as well as in coastal areas in recirculating aquaculture systems (RAS) and can be marketed worldwide. Through state and federally-supported research, technology for artificial mass propagation of SF and BSB has been developed. Adult broodstock SF have been photothermally conditioned and induced to spawn throughout the year, and culture conditions for raising larvae through metamorphic stages have been standardized. Studies on growout of SF juveniles in near commercial scale RAS showed no differences in growth rates in seawater and in freshwater throughout a 16-mo. production cycle to 600 g marketable size, suggesting a versatility for RAS culture in both coastal and inland areas independent of salinity of water resources. To shorten the growout period, protocols are being developed to produce faster-growing all-female SF through chromosome manipulation techniques (i.e., gynogenesis).
Protocols for controlled maturation and induced spawning of BSB and for rearing larvae to juvenile stages have also significantly advanced. Juvenile BSB utilized high percentages of soybean meal in substitution for fish meal in artificial diets, indicating an excellent potential for formulating sustainable practical feeds. Fingerlings (~ 27 g mean wt.) grown in a near commercial scale RAS on a commercial diet at ~ 21 oC reached an average premium size of 682 g (range = 328-1,350 g) in 570 d and a final biomass density of 52 kg/m3. Current annual niche market demand for fresh BSB (whole on ice @ $7.50 per lb) in the state of NC is estimated at 310,977 lbs. Out-of-state metro markets are under study.
Through the support of economic development organizations and private-public partnerships in NC, hatchery, nursery and growout technologies are being transferred to commercial practitioners, and pilot demonstration projects for flounder and BSB are underway. Improving cost and availability of fingerlings, growth rates (via domestication and sex control), zero-exchange RAS technology, development of sustainable feeds, and knowledge of niche markets are keys to the transition from pilot to commercial scale production of these species.
