Land-based Recirculating Aquaculture System (RAS) is an advanced, typically environmentally benign technology used to grow safe and healthy seafood in large tanks. Utilizing RAS for land-based farming of aquatic animals has notable advantages over marine and other net-pen aquaculture operations. Unlike offshore farms, RAS provides Aquabanq with near-total control over growing conditions and inputs. This technology allows us to optimize growth, prevent diseases, and ensure quality, in order to supply seafood according to a predictable year-round production plan.
The overuse of antibiotics has transformed what had been a hypothetical menace into a clear and present one: superbugs, bacteria that are highly resistant to antibiotics. Eliminating entry points for pathogens and parasites as well as providing overall good health conditions for our fish and shrimp in a tightly controlled RAS environment ensures that no antibiotics are used, be discharged with effluent, or enter the food chain through the consumption of our product.
The water in our RAS is reused and continuously treated. The system decreases dissolved carbon dioxide and nitrogen gas to levels closer to atmospheric saturation, and increases dissolved oxygen concentrations above atmospheric saturation levels. Additional treatment units disinfect and oxidize organic wastes and nitrite in order to supplement the effectiveness of other water treatment units.
Each of our RAS grow-out units is designed to produce 2.7 million pounds of harvest-sized fish every year.
The system was designed for low maintenance, energy, and feed efficient operation. Our energy consumption per pound of fish produced is significantly lower than the industry average and we deploy the most efficient oxygen dissolving process equipment operating at only 0.3 bar—10 times less than the current industry standard—to create a stress-free, healthy environment for the fish in our tanks and improve Feed Conversion Ratio (FCR).
For RAS fish tanks, it is hard to find a more cost-effective and long-lasting solution than glass-fused-to-steel technology. Our glass-lined tanks that are made in Germany can be extended and even re-sited thanks to their long term asset value. Rapid and cost-effective site installation reduces project timescale, costs, and requirement for on-site equipment. This technology provides for exceptional corrosion control, abrasion resistance, and long service life with no cracking, chipping, or leaking.
All safety and mission-critical RAS components are supplied in multiple units to ensure life support for the animals in case of an equipment breakdown or power outage. The oxygen production system is backed up by on-site large capacity liquid oxygen tanks and emergency power generators will start automatically after detecting any interruption in service.
All data such as fish feed consumption, photoperiod, water temperature, pH values, and water oxygen saturation, among other parameters, are monitored and processed in real-time by the Supervisory Control and Data Acquisition System (SCADA). This centralized system assists operators with monitoring the aquatic environment and critical RAS equipment. Computer-controlled pneumatic feeders are used to transport the feed inside the facilities. These also ensure the distribution of the correct amount of feed to the individual fish cohorts at the right time as precision feeding is essential for any profitable fish farming opration.
When a cold-water RAS discharges water back into the environment, it does so under the strict conditions of the National Clean Water Act NPDES permits.* Virtually all NPDES permits for land-based aquaculture facilities in Maine require the quality of discharged process water to be cleaner than water they take in from the environment.
Our sustainably operated RAS plant will create virtually no impact on the wider ecosystem from effluents, escaped fish, or other traditionally undesirable inputs of fish farming.
To build our aquatic farms in Maine, Aquabanq has joined forces with Aquacare Environment Inc. that has specialized in RAS design and integration of world-class OEM aquaculture equipment for the past 36 years.
* The NPDES permit program addresses water pollution by regulating point sources that discharge pollutants to waters of the United States.
Our standard Zero-Discharge RAS unit is designed to produce 280 thousand pounds* of shrimp a year at a harvest size of eighteen to twenty-two head-on shrimp per pound. The production can be scaled up within just a few months as Zero-Discharge RAS discharges no liquid effluent or process waste to surface waters or the ground.
The system recirculates process water through two separate treatment loops using anaerobic and aerobic filtering process. Subsequently, the purified and oxygenated water flows back into the production tanks.
For many years, all land-based aquaculture systems used mechanical, microscreen drum filters to remove solid waste such as fish feces and uneaten feed. The sludge was then collected in tanks and transported off site to a nearby treatment facility. The process inside the anaerobic tank in Zero-Discharge RAS utilizes anaerobic bacteria to break down ammonia and proteins.
The only byproduct of this process is Nitrogen (N2), a nontoxic, odorless, colorless, and noncombustible gas that makes up the major portion of the Earth’s atmosphere. As a result, no sludge and no wastewater are leaving the system.
Our warm-water RAS design is based on a Zero-Discharge system originally developed at the Hebrew University of Jerusalem, Israel. The production unit was significantly improved, streamlined, and customized for use in commercial aquaculture.
– No effluent is released into the surrounding environment; – No discharge permit (NPDES permit) is required to operate a Zero-Discharge system; – No dependency on any large source of water to operate Zero-Discharge RAS; – Tanks are filled up with water at system startup. Subsequently, water will only be added to compensate for the splash and evaporation losses;** – Can be built in urban and rural areas, or right next to a large transportation hub; – Dramatic reduction of transportation cost and CO2 footprint; – Low investment costs per pound of shrimp (or fish) produced; – Low operating expenses per pound of shrimp (or fish) produced; – Low electricity consumption per pound of shrimp (or fish) produced; – Easy, quick assembly and construction; – Low maintenance; – Renewable heating source; – Superior bio-safety; – Low density,*** low risk aquaculture.
*125 metric tons ** Evaporation loss, typically 0.05 per cent of the total tank volume *** The stocking density for Pacific white shrimp (L. vannamei) does not exceed 15 kg/cu m (0.94 lb/cu ft).