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Sorting Salmon

Sorting Salmon

Genomic tools will identify Atlantic salmon with the best natural variation

Salmon farming has come a long way since 1985, when Gifford Cooke and his sons Glenn and Michael of Blacks Harbour, New Brunswick, established their first marine site on the Bay of Fundy with 5,000 Atlantic salmon smolts.

Today, Cooke Aquaculture is North America’s largest independent salmon farming company. Its operations in four provinces and the state of Maine process and sell more than 72.5 million kilograms of Atlantic salmon a year. And recent advances in genomics research seem likely to transform it into a major competitor in the global market.

Scientists have now mapped the genome of the Atlantic salmon, allowing the aquaculture industry to use genetic markers to determine which offspring have inherited the best traits for fish farming. These include resistance to diseases and parasites such as sea lice, improved growth rate, rapid adaptation to seawater, and delayed sexual maturity.

In the past, conventional selective breeding took four years. In a cycle mimicking nature, in the fall of each year, eggs are fertilized, incubated, and hatched in temperature-controlled freshwater tanks. They are reared here from alevins to fingerlings to smolts over 12 to 18 months. At that point, siblings of the best broodstock are transferred to ocean farms for up to 23 months. When they reach 4.5 to 5.5 kilograms, they are harvested and evaluated.

Using genomic selection, Cooke Aquaculture can cost-effectively screen Atlantic salmon for desirable traits when they are just fingerlings. Families exhibiting poor trait characteristics will be eliminated early from the breeding program. This shortens the evaluation process from up to four years to just 12 to 18 months.

“We are intentionally screening for the best natural traits, and speeding up the process,” says Dr. Keng Pee Ang, Cooke’s vice-president of research. In the short term, he says, using genomic tools to improve the selection process will increase sales by $18 million a year, and add 40 processing jobs.

August 2015