Experts Discuss Nuts and Bolts Of Sustainable Fish Farming

August 16, 2010

Aquaculture tanks at Freshwater Institute

Aquaculture tanks at Freshwater Institute. Photo by Glynnis McPhee/The Conservation Fund

Arlington, VA — Experts from The Conservation Fund’s Freshwater Institute will present findings from studies they have conducted to refine the process of raising Atlantic salmon in freshwater recirculating aquaculture systems at a premier, international meeting of scientists, engineers, entrepreneurs and businesspeople gathered to discuss land-based, water recirculating aquaculture.

The Aquacultural Engineering Society’s Issues Forum and the International Conference on Recirculating Aquaculture will be held back to back in Roanoke, Va., from August 18th to 22nd.

The conferences are organized by Virginia Tech and co-sponsored by the Freshwater Institute. They feature presentations and poster sessions from leading experts in recirculating aquaculture. More than 80 papers will be presented during the events.

Water recirculating aquaculture systems conserve water and resources in a system that raises healthy, tasty fish. They provide an alternative approach to ocean net pens or flow-through aquaculture systems.

More than half the seafood consumed worldwide is grown in aquaculture facilities. The Freshwater Institute’s work has focused on how to improve the operations of recirculating systems and raise the most popular market fish, such as Atlantic salmon. The research is working toward a sustainable system, one that uses grain-based feeds to eliminate demand for ocean forage fish, uses little water, imposes no threat to the health of wild fish, and eliminates polluting waste.

“Sustainability is a pretty word, but there is a whole lot underneath it,” said Joseph A. Hankins, Director of Freshwater Institute. “Our work, and this conference, is focused on the practicality of recirculating aquaculture. We are very much focused on resolving the challenges of salmon production in land based, recirculating systems.”

That focus is reflected in the papers Freshwater Institute staff will present.

Dr. Steven T. Summerfelt, who heads the Institute’s research on recirculating aquaculture systems, will moderate a symposium on “Closed-Containment Systems for Salmonid Culture.” Worldwide production of salmon, trout, and arctic char in recirculating systems has expanded rapidly in the past 5 years, and although production system design varies greatly, water quality control is a common factor. This symposium will present research and case studies that describe the interaction between recirculating system design, loading, and water quality in salmonid production systems, including details on water use, feeding rates, system exchange rate, culture tank exchange rate, production rates, treatment efficiency, waste capture efficiency, fish performance, and energy consumption. Of paramount importance will be discussion on the welfare and growth of the fish.

Dr. Christopher M. Good, the Director of Aquatic Veterinary Research at Freshwater, will lead a symposium on “Fish Health and Welfare in Recirculating Systems.” Disease is a major constraint to aquaculture production worldwide. Farming operations that employ recirculation technology face unique challenges related to the potential for retention and accumulation of fish pathogens in system water, as well as the management of water quality parameters to avoid environmental conditions optimal for opportunistic disease agents. In addition, the welfare of farmed fish is becoming increasingly scrutinized by regulatory agencies and activist groups alike, and basic research in this area, particularly in how compromised welfare impacts fish health and production, is still required. This session will focus on research related to the health and welfare of salmonids and other species raised in modern water recirculation aquaculture systems.

Good will also present a comparison between the health of Chinook salmon raised in a partial recirculating system to those raised in a traditional flow through system.

Other staff members—Dr. Brian Vinci, Mark Sharrer, John Davidson, and Tom Waldrop—will also present papers. Their work provides details and insights on maintaining water quality, fish health and performance, diets, and system design. Papers and their presenters include:

    • Activated Sludge Adsorption of Heavy Metals in a Membrane Biological Reactor Operated for Reclamation and Reuse of Recirculating Aquaculture System Wastewater — M.J. Sharrer, K. Rishel, and S.T. Summerfelt
    • Effects of Ozone and Water Exchange Rates on Water Quality and Fish Performance within Replicated Water Reuse Aquaculture Systems Culturing Rainbow Trout, Oncorhynchus mykiss — J. Davidson, C. Good, C. Welsh, and S. Summerfelt
    • Ozone Application and Brominated By-Products: Monitoring, Formation, and Destruction in Water Recirculating Systems for Fish Culture — S. Summerfelt, S. Clements, and M. Gearheart
    • Comparing Carbon Dioxide Stripping Column Performance in Freshwater and Seawater — S.T. Summerfelt, M. Gearheart, and B. Watten
    • Design and Performance of Recirculating Systems for Atlantic Salmon (Salmo salar) at the USDA ARS National Cold Water Marine Aquaculture Center (Franklin, Maine) — W. Wolters, A. Masters, B. Vinci, and Steven Summerfelt
    • Coupled Geotextile Dewatering and Activated Sludge Treatment of Biosolids Discharged from a Recirculating Aquaculture System — M.J. Sharrer
    • The Cost and Effectiveness of Solids Thickening Technologies for Treating Backwash and Recovering Nutrients from Intensive Aquaculture Systems — M.J. Sharrer
    • Comparing the Health, Performance, and Welfare of Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) Raised in a Pilot Partial Water Reuse System Versus a Flow-Through Raceway — C. Good
    • Rainbow Trout Performance in Circular Tank-Based Water Recirculating Systems — T. Summerfelt
    • Atlantic Salmon (Salmo salar) Growout in Freshwater Closed-Containment Systems: (1) Effects of High (20 mg/L) and Low (10 mg/L) Carbon Dioxide Concentrations and (2) Effects of Strain and Photoperiod Manipulation — C. Good
    • A Factorial Study to Investigate the Effects of Swimming Speed and Dissolved Oxygen Concentration on Rainbow Trout Performance, Health, and Welfare — T. Waldrop
    • Comparing the Effects of Grain- versus Fish Meal-Based Diets on Water Quality and Waste Production within Low Exchange Water Reuse Aquaculture Systems Culturing Rainbow Trout, Oncorhynchus mykiss — J. Davidson
    • Water Treatment Process Efficiencies in Replicated Recirculating Systems Operated with and without Ozonation at High and Low Flushing Rates — S.T. Summerfelt

On Sunday, August 22nd, conferees are invited to tour the Freshwater Institute’s research facility in Shepherdstown, WV.


For information on the issues forum and the conference visit

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