SBIR-STTR Award

This application describes the Phase I commercialization by Virginia Cobia Farms (VCF) of a combination of unique technologies including proprietary technology involving molecular salinity nutrient sensors in fish, use of intensive land based recirculation systems (RAS), novel dietary fish feed formulations as well as commercial production scale application of ARS scientists focused on development of culture technology for the production of cobia in low salinity closed systems. The technology will further reduce capital and operating costs of inland RAS by dramatically reducing the water salinity requirements for rearing of marine fish. The specific goals of the proposal are to ascertain the optimal size of cobia juveniles that can be acclimated to low salinity conditions utilizing VCF?s proprietary technologies for low salinity culture of marine fish. Additionally, novel diet formulations will be developed and tested to optimize dietary contributions to higher growth and survival of juvenile cobia during and after acclimation to low salinity conditions. Once size selection and dietary formulations have been optimized for low salinity conditions, cobia juveniles will be reared using this knowledge at commercial stocking densities of > 30 kg/cubic m to a size of approximately 100 g. These key efforts will validate VCF?s low salinity culture technologies on a commercial level and set the course for company expansion in Phase II and III. Our commercial effort also addresses key items in the recently released USDA National Program 106 Aquaculture Action Plan 2010-2014 including fostering the development of a US domestic aquaculture industry that produces fish in an environmentally responsible and sustainable manner. Successful commercialization of technologies developed during this SBIR project will solve a key bottleneck in development of US marine fish aquaculture using either land based RAS low salinity production or onshore marine fish hatcheries for offshore fish production. OBJECTIVES: The specific goals of the proposal are to ascertain the optimal size of cobia juveniles that can be acclimated to low salinity conditions utilizing VCF's proprietary technologies for low salinity culture of marine fish. Additionally, novel diet formulations will be developed and tested to optimize dietary contributions to higher growth and survival of juvenile cobia during and after acclimation to low salinity conditions. Once size selection and dietary formulations have been optimized for low salinity conditions, cobia juveniles will be reared using this knowledge at commercial stocking densities of > 30 kg/m3 to a size of approximately 100 g. APPROACH: VCF will produce n=25,000, 0.5-1.0 g fully weaned cobia from our internal hatchery/nursery program. These will be size graded at 2 months post hatch and a portion of the largest (Upper Half) and smaller (Lower Half) fish of the juvenile population will be utilized for studies described below. Juvenile cobia will be stocked into 1 meter diameter circular receiving tanks at 35 ppt in an RAS system maintained at 27 C. After 1 week of tank acclimation, three groups of approximately n=500-1000 cobia will be distributed equally in three 100 liter circular tanks (n=3 treatments with 3 replicate tanks) and fed either the standard VCF acclimation diet or one of the two novel diet formulations containing feed additives (Objective 3). These fish will undergo a 2 week acclimation to VCF proprietary ionic solution corresponding to 2-3 ppt as described in VCF pilot studies above in this 18 unit RAS. During acclimation to low salinity, water quality parameters, particularly ammonia, pH and oxygen, will be carefully measured and regulated to maintain optimal levels for juvenile cobia. After acclimation, both Upper Half and Lower Half fish will be transferred to the 1.6 m circular tank systems (see Facilities and Equipment for system details) for longer term rearing at 2-3 ppt. Their corresponding matched Upper Half and Lower Half controls will be reared in the identical RAS system at 35 ppt serving as the third treatment. The best performing cobia group as determined by Technical Objective #1 studies will be utilized to complete Technical Objective #2. This group will be produced by repeating the procedure as outlined in Technical Objective #1 and the resulting 3,000 juvenile cobia will be reared in two 1.6 meter diameter circular tanks in a single RAS unit at 27 C in 2-3 ppt at an average stocking density of 30kg/cubic m. Each of their corresponding matched controls will be reared in an identical twin RAS system under identical conditions except at 35ppt. Cobia will be hand fed to satiation 6-8 times per day and supplemented with automatic feeders during night intervals at fish sizes less than 20 g to reduce cannibalism. All cobia groups will be exposed to a continuous 24 hr photoperiod. In Objective 1 of the proposed work, a minimum of two novel dietary formulations will be designed to enhance survival and growth of juvenile cobia when cultured under VCF low salinity conditions. While there is an established, proprietary diet formulation that achieves good success at acclimation to VCF low salinity conditions, recent work at VCF and Virginia Tech have identified several promising candidates to serve as feed additives. These include taurine, a selenomethionine yeast product and a mannan oligosaccharide. These additives have all shown promise in terms of aiding cobia under lower salinity conditions

Virginia Cobia Farms Phase II USDA-SBIR grant is designed to assist our company at implementing discoveries made during our Phase research I into larger scale production where the process of cobia egg to market size fish production will be integrated into a single interlocking system. Building upon fundamentals established during Phase I, VCF proposes to investigate enhanced brood stock nutrition and its potential impacts upon hatchery output, determine optimal rearing temperatures during hatchery phase of production, establish a multiple grading protocols to increase production efficiencies during grow-out and optimize stocking densities for 1 kg and 2 kg market-sized cobia. This research collectively will produce 2 and 4.4 pound fish for the live market and fillet market, respectively, in RAS consisting of an integrated system of tanks designed as a prototype that will serve as the basis for VCF's large scale expansion scheduled to occur during Phase III. For this Phase II work, VCF will focus on both the production cycle and as well as the quality and consistency of its final product delivered to consumers in the Washington, DC metro area. We will also produce 4.4 pound market size fish for sale as "bullets" (head off gutted fish) to the retail fresh fish market. Continued development and optimization of our in house dietary formulations during Phase II will further the enhance VCF's efficiency and quality control during its rearing of cobia under low salinity conditions in RAS. This proposed Phase II effort will further augment USDA funded efforts awarded to VCF itself or its municipal partner, the Town of Saltville, VA, in the areas of renewable energy generation and rural business development. Successful completion of the Phase II effort will enable VCF to drive its integrated production methods into a modular design format and implement this format in a manner that will both reduce costs and shorten delay times in additional scale up and operations. OBJECTIVES: Virginia Cobia Farms (VCF) has independently worked through critical bottlenecks at each stage of production, providing not only proof of concept, but also accumulating tremendous amounts of data relating to the biology of cobia and the critical areas of systems design that support the biological findings. The following work plan has been proposes to achieve our Phase II objectives, thus further refining and ultimately producing the optimal, integrated cobia production system for the execution of our business plan. Objective 1: Evaluate cobia brood stock nutrition to increase egg fecundity, fertilization rates and hatchability. Overview: Due our findings with respect to supplemental taurine during Phase I research, as well as related research and development, we know that our standard, wild caught brood stock diet contains approximately 2% taurine. We propose in Objective 1 to investigate the impacts of supplemental taurine on egg quality parameters in cobia broodstock. Objective 2: Optimize hatchery protocols to increase production and size of weaned animals as they leave the hatchery phase. Overview: In Objective 2, we propose to investigate the role of environmental temperature on larval survival during the oil globule stage. It is envisioned that by reducing the culture temperature, the duration of the presence of the oil globule can be increases, thus providing the developing larvae with maternal nutrition for a longer period of time. This should result in higher survival rates, as well as potentially larger fish, at the time of weaning, hence the end of the hatchery phase. Objective 3: Refine juvenile production, incorporating dietary and grading discoveries made in Phase I, to improve specific growth rates, feed conversion ratios and survival through to 100-150 g. Overview: Using our full integration model, we propose that tighter and more frequent grading and culling protocols during the juvenile production stage will result in groups of higher quality juveniles, which in turn, will lead to higher throughput into the production systems. Based upon our Phase I research, we feel confident that improved grading protocols will result in increased production efficiencies when these fish are grown to market size (1 and 2.2 kg) in the grow out systems. Additionally, further optimization of supplemental taurine levels in the juvenile production diets can provide for lower feed conversion ratios, thereby adding to increased production efficiencies. Objective 4: Optimize system design parameters in the production of 1 kg cobia for the live markets and evaluate different stocking densities in the production of 2.2 kg cobia for the filet market. Overview: In this final objective, we propose to increase the stocking densities in the culture of the live market, 1 kg, cobia to 35-40 kg/m3 by further refining our RAS designs and operation. For the 2.2 kg cobia destined for the HOG market, we propose to evaluate two different stocking densities, 30 and 60 kg/m3 during the grow out phase of production. APPROACH: Objective 1, Experimental Design: Cobia brood stock will be maintained per standard VCF brood stock protocols, but will be fed a diet containing 4% supplemental taurine along with the wild caught diet. This diet will be fed for a minimum of 5 months prior to spawning events. A control tank of equally sized cobia will be maintained so that comparisons with a standard cobia brood diet can be made. After each spawning event, the following parameters will be measured: total number of collected eggs, percent fertilized eggs, egg diameter, oil droplet diameter, hatch rate and size of larvae at hatch. Taurine levels in the eggs, day 3 post hatch and weaned juveniles will be analyzed via HPLC. Objective 2, Experimental Design: Larvae will be stocked out according to established VCF hatchery protocols at day 1 post hatch at a rate of 20 larvae per liter. In one hatchery system containing 6 replicate tanks, the water temperature will be lowered at a rate of 1 C every 2 hours from spawning temperatures to approximately 25 C. The other hatchery system will be maintained at the standard temperature of 28 C according to standard VCF hatchery protocols. Measurements of the oil globule in fish from each treatment will be taken daily until disappearance. Standard lengths of 10 fish per treatment will be taken daily. At weaning, all fish will be counted and survival rates will be calculated. Objective 3, Experimental Design: Juvenile cobia coming out of the hatchery systems will be fed either a standard commercial starter diet or an experimental formulation with supplemental taurine for the next 30 days. At this point, the fish will be graded within their respective dietary treatments into 4 groups, with the smallest grade being culled out of the production cycle. The remaining cobia will be redistributed into the juvenile systems, maintaining their dietary treatments and fed for an additional 30 days. The fish will again be graded, only into three separate grades, with the lower 10% of these fish culled and the remaining fish being transferred into the juvenile rearing tanks for grow out to 100-150 g at a final stocking density of 30 kg/m3. Specific growth rates, feed conversion ratios, and survival rates will be monitored at each 30 day grading period. Hematocrit, plasma taurine levels and liver condition will be evaluated in a subsample of 20 fish per treatment at each grading period. Objective 4, Experimental Design: Cobia from Objective 3 of our Phase II proposal at 100-150 g will be graded, with the middle grade being stocked into each of eight, 11 m3 grow out production tanks. These eight production tanks will represent the 1 kg cobia destined for the live market. The remaining top grade of these fish will be stocked into the remaining four grow out production tanks, two stocked at 30 kg/m3 and the other two at 60 kg/m3. Fish in all production tanks will be fed our in-house proprietary grow out feed formulation. Monthly, a subsample of 100 fish will be weighed from each tank to monitor SGR and FCR. During the monthly sampling events, a subsample of 5 fish from each tank will be sampled for hematocrit, plasma taurine levels and liver index condition