This Small Business Innovative Research (SBIR) Phase II project's overall goal is to commercialize a robust, continuous culture production system for rotifers (Brachionus rotundiformis; s-type), the major live feed source for marine larval fish. A major bottleneck in the expansion of the marine aquaculture industry in the United States remains the lack of commercial live feed production technologies to support the grow-out industry. Specifically for rotifer culture, there exist limited standardized design and operational criteria for continuous culture methods that could facilitate increased productivity and consistency of supply. The inability to supply microalgal/zooplankton feeds cost-effectively (quantity) and consistently (quantity and quality) continues to be a major limitation to the expansion of the marine aquaculture industry.
The broader impacts of this technology are simplification of fingerling production which will lead to rapid expansion of marine hatcheries and hence a dramatic increase in the availability of lower cost marine fry and fingerlings for aquaculture grow-out in ponds, ocean cages and/or indoor recirculating systems. This research has the potential to help jump-start the marine aquaculture industry by eliminating one of the key limiting factors to increasing the production of many marine species, i.e. the unavailability and the high cost of fry and fingerlings. Aquaculture production of the more popular marine finfish will relieve the pressure on commercial fish stocks that are currently severely threatened or overfished and allow culture under highly controlled, biosecure conditions using commercial formulated diets.
This project sought to design and commercialize a robust, turnkey, automated continuous culture system for the production of a live zooplankton species known as s-type rotifers (Brachionus rotundiformis). These small rotifers are commonly used in aquaculture hatcheries as live feed for marine larval finfish. Our specific goal was to design a system that dramatically reduces the typical high costs of live feeds production associated with manual batch culture. Labor is probably the most expensive cost component, requiring a trained technician to manually perform multiple rotifer population counts daily. This task is tedious and time consuming but essential to gauge population health and adjust the quantity of algae feed added to the culture. The AST Rotifer System saves time, money, and effort by monitoring the in situ rotifer population and adjusting feed (algae) input in realtime. The initial turnkey system is capable of producing 100 million rotifers per day with a standing population of 656 million rotifers (at 2,360 rotifers/ml). We describe our product as "turnkey" because it is sold as a complete package and requires minimal set up labor. This system was also designed to be easily scaled up by simply increasing the volume of the culture tank and biofilter without changing the control system. The major components developed in-house are the rotifer and algae density sensors, a touch screen controller, associated controller software, and a custom culture tank with integral moving bed biofilter. The rotifer and algae sensors are the core technology enabling closed-loop control. This decreases production costs by automating routine tasks, eliminating the need to manually count rotifers, and optimizing feed input and consumption while reducing the need for major daily water exchanges and/or chemical addtion to maintain good water quality. AST developed operational and maintenance protocols based on detailed analysis of the optimal water exchange and feed dosage required for steady continuous growth and health of the rotifer population. With the completion of software and sensor development, we are within 30 days of deploying a full scale commercial prototype. After rigorous in-house trials, we plan to field a beta system within 3-4 months.
