By Gina Forsyth
A company providing cutting edge technology to the aquaculture industry has found a new home at the former University of BC research farm south of Campbell River. Maureen Ritter, Managing Director of Canada Cryogenetics Services, said recently that the Norway-based company did trial demonstrations of their milt-freezing and storage services for Marine Harvest Canada (MHC) in 2010 using their mobile lab trailer.
“The ability to thaw and fertilize eggs using our own cryopreserved product is a positive step forward,” said Dean Guest, MHC’s Freshwater Production Manager. Marine Harvest has been a client of Canada Cryogenetics since 2010.
Marine Harvest delivers milt, also known as sperm, from the farms in a company-specific cooler to a secure and “clean” drop off zone that is scrubbed and disinfected after each delivery. Deliveries
are routinely limited to a single company per day and cleanliness protocols are strictly adhered to. “After each production day, the staff disinfects all surfaces such as counters, equipment, cabinets, walls and floors in the lab,” said Maureen.
The milt is transferred by Canada Cryogenetics staff into plastic strips called Square Packs that can each hold enough sperm to fertilize upwards of 3,000 eggs. Traditional technology using “straws” accommodates enough product to fertilize a maximum of 60 eggs at a time. Once the milt is contained in the Square Packs, they’re loaded onto a plastic holder that is stored in an aluminum tube and placed into a 500 litre sterilized canister reserved by Marine Harvest. The tube is submerged and frozen in tanks containing liquid nitrogen at temperatures of -130˚ Celsius. Each tank has the capacity to hold up to 2,500 Square Packs – enough milt to fertilize approximately seven million eggs.
This significant step forward means that milt collected in any one year can be used to fertilize eggs in other year classes leading to more consistent performance between groups, said Dean. It can also be used to provide genetic material in future generations if required.
Liquid nitrogen levels are visually inspected daily and topped up on average every week. The product keeps indefinitely and is returned to Marine Harvest for egg fertilization as needed, usually in the fall.
Marine Harvest staff will be trained on-site at company hatcheries in the correct protocols for thawing and fertilizing eggs using the cryo-preserved product. The company, which also provides services to Marine Harvest Chile, has a satellite office in New Brunswick.
Canada Cyrogenetics plans to introduce milt activator, extender, and dilutor later this year.