The numbers floating around Scott Hinch’s mind are daunting, if not impossible, to fathom.
Infrastructure costs that veer into seven digits. Thousands of kilometres of water. Tens of millions of fish.
A forestry professor with the University of B.C.’s Forest and Conservation Sciences department, Hinch is responsible for heading up first-of-its-kind research into salmon tracking and health monitoring.
His work was formally recognized on a global scale this week, having received the Exceptional Leadership – Professor designation from the national non-profit group Mitacs.
The basis for Hinch’s award is rooted in a seven-year study he recently wrapped up that tracked the migration patterns and survival rates of millions of sockeye and steelhead spanning from the Interior of B.C., down the Fraser River and across Vancouver Island.
Hinch’s team was the first to employ telemetry tracking on such a large scale and for an extended period. Telemetry tracking is similar to depth finders on boats — acoustic pings are sent down into the water, which then ping back up to the surface to tell the operator what’s lurking in the depths.
It’s the same kind of system commonly used in wildlife tracking, where bears, wolves or moose are outfitted with collars that send signals back to a receiver.
“It’s like trying to find a needle in the haystack,” Hinch told the Courier.
In Hinch’s case, he and a team of researchers, along with members of the St’át’imc First Nation, took a deep dive into the life cycles of salmon originating from the Chilko River.
Electronic transmitters the size of a Tic Tac were placed on both juvenile and adult salmon, which would then send signals to hundreds of receivers, referred to as listening stations, spread across the Fraser River and Strait of Georgia. Throughout the process, Hinch’s team gleaned insights into the fish’s travel patterns and preferences, mortality rates and physiology.
“This was the first time anyone had ever done it, so it was all new,” Hinch said. “We didn’t even know if we could put transmitters in the fish this size and whether they would survive.”
With some salmon runs in B.C. recording a dismal one per cent return rate, survival was the name of the game throughout Hinch’s research.
His work in freshwater ecosystems was particularly eye opening. The usual suspects — climate change, pollution, overpopulation — were not responsible for dizzying mortality rates among juvenile salmon.
Instead, it was nature doing its thing.
Hinch’s team noticed millions of young fish moving only after dark, a behavioural pattern that was unusual and pointed to predators on the prowl. A separate study altogether found that bull trout would move out of Chilko Lake at night and into barely a metre of water in a section of the Chilko River where the young fish had to pass through.
Cue the feeding frenzy.
“These trout were gorging themselves,” Hinch said. “If you were to pump their stomachs, you would have up to 85 juvenile salmon in their stomach at one time.”
Those findings helped tie up other ends of research that show turbid, murky water is ideal for those same fish. And in fact, once the fish reached those conditions further down the Fraser, their mortality rates dropped to almost non-existent levels.
Other first-of-their kind findings showed that predators sought out injured or sick fish specifically. That was long believed the case anecdotally, but not recorded in a research setting.
“You learn in school that the predator will always take the weak fish, but this was the first time you could actually say definitively, ‘Yes, these predators somehow are picking up these fish that are physiologically compromised in some fashion,’” Hinch said. “We still don’t know how they’re doing it and we’d like to figure it out. But that’s remarkable finding.”
Given that so few salmon make it from freshwater to the ocean, Hinch’s research focus now turns to the marine environment. While the freshwater research pointed to natural deaths, the same likely won’t be said about Hinch’s findings in the Strait of Georgia.
“There’s no doubt that these fish, when they get out into the ocean, are into an ocean that’s much warmer, somewhat more acidic and somewhat less productive from a food sense,” Hinch said. “We used to have returns of 10 per cent. Now we’re down to one per cent. That is an ocean effect, clearly. Things are changing out there.”