Frozen Chinook salmon milt works wonders
Methods for the preservation of animal sperm using freezing- or cryopreservation- have been in use for a long time, but trials with Chinook salmon (Oncorhynchus tsawytscha) milt have showed mixed results until now. This species of Pacific salmon is of importance to not only salmon farmers in Canada and New Zealand, but also to both commercial and sport fishers in the Pacific Northwest corner of North America. It is the fish that can reach the largest size of all five species of Pacific salmon, with the biggest Chinook ever caught coming from a fish trap in Alaska in 1946, at some 126 pounds or 57.2 Kg. By comparison, the largest Atlantic salmon on record appears to be a 49.4Kg (~109 pounds) fish caught in the River Hope in the UK in 1960. Being able to reliably preserve the best genes for growth, survival and genetic diversity for future generations benefits both fish farmers and wild salmon managers.
A two-year trial of freezing and subsequently thawing and using the cryopreserved milt from Chinook salmon in British Columbia showed an average fertilization rate of Chinook salmon eggs of about 95 per cent- very close to the rate experienced by using fresh milt. The Norwegian company Cryogenetics AS recently issued the following Press Release;
CRYOGENETICS Ltd. based in Norway, TRI-GEN FISH IMPROVEMENT LTD. and CREATIVE SALMON COMPANY Ltd. has, during a joint project, established an innovative cryo-preservation protocol for milt from Chinook salmon. During a two-step trial period in 2009 and 2010, milt was cryo-preserved to test the robust cryo-preservation protocol used by Cryogenetics on other salmon species. The Cryogenetics method provided a 95% average (fertilization rate), which is very promising in the process of offering a well-functioning commercial alternative the Chinook producers. It is expected that the cryo-preservation technologies will have a positive impact on how breeding companies and conservation authorities can safely store and later use genes. With the use of the Cryogenetics product SquarePack® 1.000 Chinook eggs can be fertilized by one cryo-preserved unit. Cryogenetics Ltd. specializes in developing cryo-preservation technologies for fish milt and embryos, and provides commercial products for milt from Atlantic salmon, Rainbow Trout and Cod. The company issued a press release in January 2010 informing of the breakthrough of cryo-preserving a Cod embryo down to -130°C. The company has its headquarters and R&D department in Hamar, Norway, and does commercial cryo-preservation out of laboratories in Trondheim, Norway, Oyster River, Canada and Puerto Montt, Chile. TRI-GEN Fish Improvement Ltd. specializes in research, development and management of Coho salmon, Chinook salmon, Atlantic salmon and Rainbow trout broodstock programs throughout the Pacific Northwest and Western Canada regions.
Creative Salmon Company Ltd. was established in 1990 and is one of only a few premium growers of Chinook salmon in Canada and the world and operate in the traditional territory of the Tla-o-qui-aht First Nations in Clayoquot Sound on Vancouver Island, BC. Creative Salmon has a committed and dedicated workforce of approximately 55 full time staff, in which all of the employees are the key to continued success. The company practices of a low density/low-stress environment allow the staff to be in close contact with the fish and follow husbandry standards that result in healthy, high quality salmon leaving behind the smallest environmental footprint. Creative Salmon now produce in excess of 1,500 metric tons per annum by operating an integrated production cycle. With painstaking control of quality from egg to harvest, they have established an enviable reputation for high quality Chinook salmon, serving the most discerning clientele throughout Canada, the USA and Japan
The project has been financially supported by Innovation Norway.
