Hooked on salmon: student leads record-breaking fish count project

Clad in hip waders, the weight of the cool river flow buffeting the protective layer keeping him dry while immersed in the science of salmon enhancement is exactly where Tristen Dieleman wants to be. 

Tristen is a second-year diploma student in the VIU Fisheries and Aquaculture program. He came to the university as a mature student, knowing that a career in fisheries was where he wanted to be. 

“If you're passionate about whales, wolves, bears or trees, you have to get passionate about salmon because the nutrients from salmon feed that entire ecosystem,” says Tristen. “All of it depends on the salmon that head into a great big ocean when they are only inches long. They feed other creatures, feed us, the ones that survive come back to the river, feed more animals, spawn, die and nourish the environment. It’s an amazing process.” 

His experience working in a local river this past fall is helping Tristen define his career path. 

Under the direction of Professor Duane Barker, Tristen participated in a chum and coho salmon counting assessment on the Chase River in south Nanaimo that yielded startling results. 

Four teams of students collected data from specific sections of the river. They measured the velocity and discharge of their section of the stream, assessed overhead foliage and counted the number of salmon swimming upriver to spawning grounds. 

“Something spectacular happened last year,” says Tristen. “2024 was a record-breaking chum salmon return. We estimated the escapement for chum salmon to be 5,624, while for coho salmon, it was 1,136. The fact we’re getting returns such as this in a system suffering from anthropogenic effects from human development is huge.” 

The estimated escapement returns for chum salmon in 2024 were 5 to 7 times higher than the last decade since monitoring by VIU students began in 2011, and the coho salmon returns observed were 3 to 7 times higher than the past two decades since monitoring began in the 1990’s. 

All data collected by the four teams at the end of the salmon run was collated and analyzed by the students to determine the environmental conditions that triggered the salmon migration. 

“Tristen was a true leader. He helped train new students on all sampling procedures, was responsible for compiling all field data and served as liaison between his team and I,” says Duane. “This was a great training opportunity for Tristen to further develop skills in leadership, organization and communication and he excelled."

Photos courtesy of Tristen Dielemnan

Duane shares the data with the Department of Fisheries and Oceans (DFO). 

“Last semester, the returns were so good that our results were published in the DFO salmon escapement bulletins to showcase how well our rivers do,” says Tristen. “DFO uses that data for management plans.” 

Duane says this field training helps develop a sense of habitat stewardship among students. They learn the importance of monitoring and maintaining critical physical features of an urbanized stream. 

“Many students are surprised that an urbanized stream could contain different species of spawning salmon,” he says. “They soon understand the importance of conserving such habitats. They understand the importance of the types and amount of vegetation around a stream and in-stream features like logs, pools and riffles.” 

Tristen says the fieldwork helped him develop competence as a leader managing a team as well as skills in data computation such as estimating discharge and flow levels and how that affects rivers, all applicable to working in the sector after graduation. 

“Where do I want to go after graduation is a great question,” says Tristen. “There are opportunities for a career in fisheries and aquaculture around the world.” 

Originally, Tristen thought working with freshwater trout was where he would end up, but that changed as he journeyed through the diploma program. 

“As I’ve gone through the program and learned what I’ve learned, I’ve realized what I don’t know is even greater; you realize you don’t know 10 other things,” he explains. “One thing for certain is regardless of where I end up, I’m going to enjoy it. Because I’ve enjoyed the entirety of the program since I have been here. Every course has information relevant to what I enjoy in life and my passion. As long as there are fish, that is where I will be.”