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More sustainable consumption choices through genomics and breeding of farmed fish

Increased fish consumption is recommended for both health and environmental reasons. Continued growth in fish consumption over the last few decades has been possible through expansion of fish farming. Globally, the volume of fish farming is already greater than beef meat production. The goal of the Ministry of Agriculture and Forestry is to triple farmed fish production in Finland by 2030. 

Effectiveness of selection breeding and the power of genomic selection

We examined how much the national breeding programme for rainbow trout—maintained by Luke’s statutory services—has improved fish traits that affect farm profitability, ecological footprint, and fish welfare. Moreover, a genomic selection method was developed to improve rainbow trout resistance against columnaris disease.

Genomic selection is based on the DNA profile of individual fish and is particularly suitable for improving disease resistance. Columnaris disease occurs in small fingerlings, especially when the water is warm, and it has a major impact on fish welfare, as well as the economic performance of the fish farming industry.  

Photo: Omar Levin

Millions of euros worth of benefits expected from the breeding programme

The data on more than half a million rainbow trout specimens shows that, since the 1990s, the selection programme has improved feed efficiency, as well as fish survival and growth. This genetic improvement results in about €4–5 million cost savings each year in production, which is comparable to the size of the entire Finnish coastal region’s fish farming industry.  

Selection augmented with genomics can improve rainbow trout resistance against columnaris disease

The method of genomic selection was validated at a commercial farm. Better resistance against columnaris disease raises fish welfare and mitigates the adverse effects of increased water temperatures due to climate change on fish farming. The developed genomic selection has already been used to support the sector through Luke’s company cooperation.

Farmed fish increasingly sustainable for consumers  

A large proportion of rainbow trout reared in Finland have roots in Luke’s selection programme, and hence the improved rainbow trout stock and selection methods directly benefit the industry and consumers. Improved feed efficiency also reduces nitrogen and phosphorus runoff from fish farms into aquatic environments, such as rivers, lakes, and eventually, the Baltic Sea.  

The study was conducted by Luke, in collaboration with Savon Taimen Oy and the Roslin Institute (UK), under the EU-funded Horizon 2020 project “AquaIMPACT”. Luke’s expertise in the project includes utilisation of large pedigrees and genomic data in the development of selection programmes. 

“The decades-long development of the rainbow trout breeding programme is a good example of how Luke’s statutory services, international research, and company cooperation can be combined, in order to improve the self-sufficiency of Finnish fish farming”, commented AquaIMPACT coordinator Antti Kause. 

 

Based on following publications:

Fraslin C, Koskinen H, Nousianen A, Houston RD, Kause A. Genome-wide association and genomic prediction of resistance to Flavobacterium columnare in a farmed rainbow trout population. Submitted to Aquaculture. 

Kause A, Nousiainen A, Koskinen H. Improvement in feed efficiency and reduction in nutrient loading from rainbow trout farms: The role of selective breeding. In revision, Journal of Animal Science.