RAS report card - How RAS deployments have evolved to make business case for adoption

Authors: SUMMERFELT, STEVEN - Freshwater Institute; TERJESEN, BENDIK - Cermaq - Norway

Submitted to: Hatchery International Magazine
Publication Type: Trade Journal
Publication Acceptance Date: 4/19/2018
Publication Date: 5/29/2018
Citation: Summerfelt, S.T., Terjesen, B.F. 2018. RAS report card - How RAS deployments have evolved to make business case for adoption. Hatchery International Magazine. e3143. Available https://www.hatcheryinternational.com/recirc/ras-report-card-3143.

Interpretive Summary:

Technical Abstract: Recirculating aquaculture systems (RAS) technology development has been and continues to be a melding of borrowed engineering. Components of RAS originate from municipal and industrial wastewater treatment industries with applied research and development specifically on aquaculture technologies by academics in public and private institutions, as well as a little creative ingenuity provided by farmers, consultants, and system suppliers. This melding of technology has not always worked, but we are now seeing many more RAS facilities meeting their production goals. Today, market-size Atlantic salmon are already being produced at commercial RAS facilities in Canada, Europe, and China, but such facilities are just beginning in the U.S. The first commercial RAS farm in the U.S. to produce 4-5 kg Atlantic salmon, Superior Fresh (Wisconsin), will begin marketing salmon and steelhead this summer; they have already begun production of just under 1000 ton/yr of salad greens. In Florida, Atlantic Sapphire is building a RAS complex that is said to be capable of producing nearly 8000 tons of market-size Atlantic salmon annually, with a later upscaling to 90 000 tons per year. Following these leaders are Whole Oceans and Nordic Aquafarms; both are working to permit and begin construction on large RAS farms to produce Atlantic salmon in Maine. Meanwhile, Hudson Valley Fish Farm has started marketing steelhead produced in their RAS facility in New York; and, AquaBounty has requested permission to produce their “AquAdvantage” Atlantic salmon at an existing RAS facility in Indiana. There are several other projects that haven’t gone public yet, but these could easily push total U.S. investment towards $500 million by 2020 and much more by 2030. Another use for commercial RAS that has been developing rapidly in the last decade is for producing postsmolts of Atlantic salmon. Postsmolts are salmon that have achieved sea water tolerance and weighing less than 1-2 kg. By using postsmolts for stocking in sea, instead of normal-sized smolts at around 100g, it is possible to reduce sea phase time and fish mortalities, reduce issues with sea lice, improve harvest volume, and more efficiently use sea sites. Currently, this technology is developing mostly in Norway, but salmon farmers also in other countries are looking into this production strategy. The facilities needed to produce postsmolts on land can be an order of magnitude larger than for smolts. Facilities capable of producing several 1000s of tons per year are now commonplace, and each provides total tank volumes exceeding 25 000m 3. This development places new and increased requirements on the efficiency and reliability of RAS. There are many advantages with brackish water salinities, around the isotonic point for the fish, i.e. 10-12 ppt salinity, in terms of growth, FCR, and skin health. However, there continue to be challenges created when salmonid RAS are built for use with salinities of greater than about 5-12 ppt. In the past, salmon smolt have always been produced in freshwater RAS and the farmers and suppliers have considerable experience with such freshwater production systems. In contrast, many of the RAS used to produce post-smolt and even market-size salmon are using brackish water and even full-strength seawater. Adapting RAS to seawater has sometimes created challenges, as water treatment processes must be larger to account for reduced efficiencies in CO2 stripping, nitrification, and oxygen-holding capacity in seawater. These differences make brackish-water RAS more expensive and riskier than a freshwater RAS of similar production capacity. Challenges remain when implementing RAS; the devil is clearly in the details, as many RAS producers still face problems. Yet, continued government and industry support for education and training of future generations, as well as improved tech