Commercial wild harvest of rainbow smelt populations is the principal source for supplying both the live bait and human consumption markets for this species. Unfortunately, populations of smelt have been in decline in the Northeast for decades and in 2004, NOAA National Marine Fisheries Service listed rainbow smelt as a species of concern in the Gulf of Maine. It is inevitable that commercial and recreational smelt harvesting will be further restricted or halted as wild populations continue to diminish. Opportunities for developing cultured rainbow smelt to supplement and eventually replace wild harvest are increasing. The only obstruction has been developing husbandry methods and processes for this species. Our 2006 Phase I research project proved the feasibility and methods required for extensive (pond) culture. Our Phase II project will capitalize on those discoveries and develop intensive culture methods for indoor grow-out in recirculation systems. The commercialization plan included in this Phase II project will integrate intensive and extensive methods and present a cohesive training and support program for future smelt growers. Our ultimate goal is to shift reliance upon a stressed wild population and eventually provide market needs with a farmed aquaculture animal. OBJECTIVES: The principal goal of this project is commercial production of rainbow smelt in the Northeast Rainbow smelt (Osmerus mordax) are a finfish species native to the northeastern United States and Canada. Unfortunately, populations of smelt have been in decline in the Northeast for decades and in 2004, NOAA National Marine Fisheries Service listed rainbow smelt as a species of concern in the Gulf of Maine. It is inevitable that commercial and recreational smelt harvesting will be further restricted or halted as wild populations continue to diminish. Commercial production (culture) of rainbow smelt would reduce fishing pressure on wild stocks and provide significant economic opportunities for aquaculturist in the Northeast. In Maine, laws restrict the importation of any baitfish. This creates enormous marketing opportunities for aquacultured rainbow smelt to support the lucrative recreational fishing industry. With prior USDA support, practical methods for production of smelt larvae (Ayer et al., 2005) were developed. With our USDA/SBIR Phase I grant, we successfully developed extensive culture methods for smelt. During our research we found that while extensive culture of smelt remains a viable mode of production, intensive production may be more effective. Present supply of market demands come almost exclusively from commercial harvest of wild smelt populations and present market demands exceed wild resources. Successful culture of rainbow smelt will replace harvest of wild smelt, stabilize availability, increase marketability, and stabilize market prices. With our USDA/SBIR Phase I grant, we successfully developed methods for extensive pond culture of smelt. During that project, we found that while extensive culture of smelt remains a viable mode of production, intensive production may be more effective. Our Phase 2 research focuses on optimizing intensive culture of smelt to a marketable size. In our ultimate species commercialization plan, feed-entrained smelt larvae will be produced and available to bait growers (intensive or extensive) in New England. We will offer aquaculture hardware and supplies, fish feed, and consulting services, as well as hands-on training seminars at our hatchery and pond culture facility specifically tailored for smelt production. Developing cost effective and reasonable intensive culture techniques, we believe, are obtainable in this project APPROACH: First objective is to re-asses the Phase I feed entrainment protocol and diet study at pilot-scale. Greenwater culture of Nannochloropsis oculata/rotifers utilizing semi-continuous culture, up-scaled to commercial production levels, cultures maintained at FAO, 1996 protocols. Rotifers enriched with microalgae fed to smelt larvae for 28 days post hatch (DPH) in larval tanks. Weaning/growth trial 28 DPH to 75 DPH. Larval smelt will be placed into Intermediate Feed Entrainment Tank systems(IFET)(recirculation aquaculture systems (RAS),each consisting of 3(700 L)tanks supported by bead biofilter, UV sterilization, mechanical filtration, aeration/oxygen, automatic feeders, lights, system alarms/monitors and a master timer). IFET units function tested, bacteria inoculated and initial start-up process initiated at least 35 days prior to larval stocking. Prior to stocking in IFET units, sample larvae examined for adequate gape and capture of Artemia. 10,000 larvae stocked in each of the 9 tanks of the 3 IFET systems for feed trials. Three tanks per diet will be assigned (Zeigler, Gemma, Otolume) with co-feeding of Artemia until total weaning occurs. A trial (first year) to determine effect of dietary protein levels on juvenile smelt growth, conducted for 120 days. Studies will be conducted in Commercial Grow-Out Recirculation Aquaculture Systems (CGO-RAS) with smelt transferred after completion of growth cycle in the IFET units . Three CGO-RAS systems (each: 3 1900 L tanks with the same configuration as IFET) utilized in trial. Previous studies demonstrate smelt obtaining market size in one growing season utilizing high levels fishmeal based protein. This study will explore growing smelt on feeds formulated with lower fishmeal content. A trial (year two) to determine optimal densities for juvenile grow-out in the CGO-RAS system. Based upon results of the feed studies (first year), optimum feed will be utilized and trial densities stocked at anticipate harvest production of 20, 30 and 40 kg/cubic meter. Optimum densities will be determined during this study. Additional trials at UNH Aquaculture Research Center will determine optimal temperature and salinity for juvenile grow-out. Temperature trials (year one, 180 days) of juvenile smelt to be conducted at 10, 15, and 20C. Salinity trials (year two, 180 days) will investigate optimum culturing salinity (5, 10, and 15 ppt) at optimum temperature results of above trial. All experiments/trials (where appropriate) evaluated using one-way analysis of variance (ANOVA, Zar 1999), to analyze the differences in growth/survival. Evaluation for optimum density/growth/feed trials determined by survival rates, condition factors (K, FBW/TL), FCR and SGW. Production/feed/operation cost-value assessment performed at project conclusion. Final project is to develop, implement and monitor a fish health management plan (FHMP) that will meet USDA-APHIS standard for inter-state sale and transport of cultured smelt. FHMP development will include testing and consultation with Micro Technologies (Richmond, Maine)
