Courier-Islander (Campbell River)
Published: June 12, 2009
What do young salmon eat? Is there enough food for them when they leave the rivers and streams and enter the ocean? These are two very important questions if you are trying to increase the number of salmon in our local waters, and in 2007 the Quinsam Hatchery approached the BC Centre for Aquatic Health Sciences about how to do just that, and so began the Discovery Passage Plankton Monitoring and Juvenile Salmon Assessment project in partnership with DFO and Atlegay Fisheries Society.
Plankton consists of small animals, plants, and bacteria that drift near the surface of the water and provide a crucial food source for marine ecosystems including young salmon. However, there is concern that juvenile Coho smolts are not being released from the Quinsam Hatchery into the sea during the optimal period of food availability. The only way to determine when peak food abundance is occurring requires repeated, detailed sampling of the plankton composition in Discovery Passage.
Plankton sample collection and analysis of the microscopic plants and animals take a lot of time and resources.
“To learn as much as possible about the food-web ecology of young coho it is imperative we have continuous year-class data to compare plankton availability with the levels of fish that return two years later,” according to biologists at BC CAHS. Over the first two years this project was primarily supported by funding from the Ministry of Environment, however due to budget cutbacks the Provincial funding was lost. With funding for 2009 secured only from the Pacific Salmon Foundation, the project was in jeopardy. That’s when three local companies: Grieg Seafood, Mainstream Canada, and Marine Harvest Canada, along with the Campbell River Salmon Foundation stepped in and provided the funding necessary for the continuation of the project for this year. Without the collective contributions from local agencies this vital initiative to learn more about our local salmon and help bring them back to Campbell River would be lost. The preliminary results of the study highlight its importance; the 2008 return of maturing hatchery-reared Coho salmon released during a 2007 plankton bloom had double the survival compared to fish released outside the bloom period. So far in 2009 the timing and composition of the plankton is entirely different from the previous two years of observations, underscoring the importance of the continuation of this project so they can learn how this will affect the coho returns they see next year.
© Courier-Islander (Campbell River) 2009, reproduced with permission