Recirculating aquaculture systems boost fish production


<p>The volume of Finnish fish farming has been estimated to double by the year 2020. Increases are expected in offshore aquaculture and recirculating aquaculture based on recirculation of water. Recirculating aquaculture systems reduce the eutrophication of water bodies. However, they place higher requirements for the health and welfare of fish than conventional systems, because the fish stocking density is higher and the water treatment systems are more complex.</p>

Recirculating aquaculture is a new, growing form of aquaculture in Finland. It involves certain health problems for fish, which differ from those encountered in conventional fish farming. In order to be better able to meet the requirements of the developing form of aquaculture, Finnish Food Safety Authority Evira is studying the consequences that recirculating aquaculture systems have on the welfare of fish.

The fish health problems found in recirculating aquaculture systems appear to be linked to water quality problems. Real-time measurement of water values together with simultaneous monitoring of fish health help identify any health and welfare problems in fish.

”The objective is to provide functioning tools to companies for the development of the recirculation technology and production. The project will also essentially improve the opportunities of fish health authorities to provide services to the industry with respect to fish health issues associated with recirculating aquaculture systems”, explains the Chairperson of the steering group of the research project, Special Researcher, DVM, PhD Perttu Koski from Evira's Production Animal and Wildlife Health Research Unit.

”In a recirculating aquaculture system, the same water is recirculated several times, which means that considerably less water is needed per each farmed kilogram of fish. The amount of discharged water is a fraction of the amount of discharge water in conventional fish farming. As a result, the nutrient levels of the discharge water are also considerably higher, which makes it easier to separate them from the water”, says Koski.

Even on the international scale, the availability of fish disease knowledge and special expertise related to recirculating aquaculture systems is limited. Evira will organise together with the Danish Aquaculture Association and the Norwegian University of Life Sciences an international workshop for experts in recirculating aquaculture systems on 3. - 4.2.2015.

The topics to be addressed in the workshop include experiences in fish diseases, special features of care, and disease prevention, as well as the welfare of fish in recirculating aquaculture systems. The management of water quality by means of e.g. biological filters will also be brought up in the discussions.

More information about Evira's research project Fish health management in recirculating aquaculture systems.

The Nordic workshop on recirculating aquaculture systems has received funding from the Nordic Council of Ministers.

Find out more about the programme.

For more information, please contact:    
Senior Researcher, Head of Section Perttu Koski, tel. +358 (0) 40 569 4541
Researcher Anna Maria Eriksson-Kallio, tel. +358 (0) 50 439 2788


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