Researchers Teach Salmon Fry to Hunt
Izumi Outdoors IncSt. Andrews - The Magaguadavic River Salmon Recovery group will release approximately 50,000 food savvy Atlantic salmon fry on Thursday, June 17, as part of a restoration effort that began in 1998. These fry have been chasing and catching their own dinners since researchers introduced brine shrimp to their laboratory tanks five weeks ago to better prepare them for survival in the wild.
Atlantic Salmon Federation (ASF) biologist Jonathan Carr, said "Since 2002, we have been releasing salmon at various life stages and monitoring to see how they fare. We released approximately 172,000 unfed fry at various sites throughout the Magaguadavic watershed last month. The fry had not begun feeding on their own, which gave them only a day or two to adjust to their new environment before they could no longer subsist on what was left of their yolk sacs. They had to then survive on food that they found in the river system."
Dr. Brian Glebe of Fisheries and Oceans Canada (DF0) said, "This is the first time that the river survival and growth of stocked unfed and fed salmon fry will be compared. I expect that the fed fry will perform better due to their pre-adaptation to consuming a live food in a hatchery environment and that the associated delay in stocking will put them into the river at a larger size, more capable of avoiding predators. Also, they will experience warmer river temperatures and a greater natural live food availability at this time."
The number of wild Atlantic salmon returning to the Magaguadavic River declined from an annual run of approximately 800 salmon to a low of two in 2004. Researchers collected wild salmon from the river in 1998 and established a live gene bank. The progeny from these salmon have been used to evaluate the benefits of different release strategies in recovering populations. The project will provide information on best practices for age and size of stocking fish into the wild, as well as for maintaining genetic diversity.
Jim Martin, chair of the restoration group, stated, "The main focus of the Magaguadavic River Salmon Recovery Group at this time is preservation of the wild genetic traits of Magaguadavic salmon. Technological advances in sonic tracking of wild salmon at sea will hopefully solve the mystery of why Magaguadavic salmon are not returning from their marine phase of life. We will maintain our stocking efforts until that happens. Our goal is to see an annual return of at least 1,000 adult salmon to the Magaguadavic River."
Of the 50 salmon that returned to the Magaguadavic River in the period from 2005 to 2009, DNA analysis has confirmed that at least 54% of those fish had originally been stocked as unfed fry and parr from the recovery program. Results obtained from this recovery project can be used to guide other restoration programs, whether local or international.
ASF will conduct surveys later this summer at sites where both unfed fry and 5-week feeding fry were released. Researchers will compare the survival and growth rates of both groups. If the brine-fed fry do better than the unfed fry, researchers will utilize this technique in future releases.
Partners in this research and restoration program include the Atlantic Salmon Federation, Fisheries and Oceans Canada (DFO), Cooke Aquaculture, provincial government agencies, angling groups, and other non-governmental organizations. The Atlantic Salmon Endowment Fund and The New Brunswick Wildlife Trust Fund have assisted in funding this project.