By Dan MacLennan / Courier-Islander
December 7, 2011
A local plankton research project could become an important fisheries management tool, if funding can be found to keep it going.
That’s the word from the BC Centre for Aquatic Health Sciences (BCCAHS) now that the five-year Discovery Passage Plankton Monitoring and Juvenile Salmon Assessment project is drawing to a close.
“The original pretext of the project was that (Quinsam River Hatchery Manager) Dave Ewart was noticing that the coho returns to the Quinsam River had been in decline for 10 years or more and he was wondering if it was the system he was using for releasing the coho smolts,” explains BCCAHS executive director Sonja Saksida. “He was wondering if there was a mismatch between the food in the marine environment and when he was releasing the coho.”
The goal of the project was to determine if the spring plankton bloom in local waters could be predicted so that coho smolts could be released to the ocean when food was most available, thereby increasing their chances for survival. Working with the A-Tlegay Fisheries Society, BCCAHS sampled zooplankton levels twice a week from early March through June. They also did a beach seine once a week to monitor coho smolt numbers and growth.
The results did not lead to the prediction model that the researchers had hoped, but the data did help to explain ocean survival in subsequent years.
“We really couldn’t predict the zooplankton blooms, but what we did notice was that there was a lot of variation from year to year in when the zooplankton occurred in our Discovery Passage area and how much.”
That year-to-year variation showed the value of spreading out the coho releases to better hit periods of food abundance.
“Rather than focus on letting pretty well all of our fish go in the last two weeks of May, which we did for many years through the ’80s and ’90s, now we stagger the releases right through the whole spring,” Ewart said. “We don’t put all our eggs in one basket, so hopefully, if there is a timing thing with the plankton blooms, one of those release groups is going to hit it and have better survival.”
While the data doesn’t predict plankton blooms, it confirms when they do occur. That, in turn, can help predict salmon returns in years to come.
“I think this kind of program is really valuable,” Ewart said. “It gives us an indicator of how things are going to do down the road. We’ve been using that. It has been a really good program because it’s stimulated a lot of talk and it’s linked in with these higher scientific groups. The centre is a lot more in the focal point because we’re linked in with PBS (Pacific Biological Station) and IOS (Institute of Ocean Sciences) because they know what we’re doing and they support it.”
Saksida said BCCAHS will be analyzing numbers over the next few months. She’s hoping to publish their findings within the year.
“We think this might be a great tool for fisheries management,” she said.
But the challenge now is to keep the data collection going next spring and in years beyond.
“We would like to see this become more of a monitoring project as opposed to a research project, so you’re not doing as intensive a sampling strategy,” she said. “It would be nice to continue collecting that kind of data because I think it would be sad to lose the continuity of the data that’s been collected to this point.”
That means finding the funding to keep the program going. Many groups and agencies have provided funding in the past including DFO, the City of Campbell River, the Campbell River Salmon Foundation, the Pacific Salmon Foundation, the Campbell River Guides Association, fish farmers and others.
“It’s not been a one-funding pocket,” Saksida said. “It’s been a lot of people interested in our local marine environment contributing to us doing this project. Without all of them, this project wouldn’t have gotten ahead. Now it’s a matter of trying to find bare bones funding just to keep at least the baseline evaluation going.”
“It could phase into a stewardship type of program,” Ewart suggested.
“This kind of project could be done by a stewardship group if there was interest in Campbell River.”