Spencer Creek fish habitat restoration going swimmingly

A freshly dug pool along the stretch of Spencer Creek by Cootes Drive did such a good job, thousands of fish moved in before new spawning areas for salmon and walleye were even finished.

Colin Oaks, aquatic ecologist for the Hamilton Conservation Authority, said he got a bit of a “build it and they will come” surprise just days into a two-week restoration project that began in late August.

The first of a series of new pools and riffles had been completed on a Friday, he said, and when he and contractor R&M Construction returned the following Monday, they noticed an unusual hue to the water.

“When we first looked at it, it was like this blue, weird, sheeny shadow that spread up and down from the riffle, and as you started looking clearer and clearer at it, you could start making out the backs of the fish,” Oaks recalled.

“It was amazing to see all of these fish utilizing this habitat that we’d just created.”

Oaks said the $185,000 restoration’s goal is to mimic features that would have been present in the stretch of Spencer between East Street and the Cootes Drive bridge before urbanization straightened its bends. The new pools and riffles provide elevation changes in what had been a fairly flat creek bed, while rebuilt sections of the creek bank use boxlike wooden lunkers to change the direction of the water’s flow much as a bend would.

The new banks were planted with ryegrass and willow seedlings for stability and eventual shade, and the embedded lunkers also provide refuge for fish from sun and predators.

Oaks said willow trees were chosen because they are native and grow quickly, and the rebuilt banks will help the minnows grow to maturity, ultimately aiding Hamilton Harbour’s remediation by providing food for predatory fish.