The Daily Courier
Sunday, January 9, 1994
It sounds fishy, but Peter Dill plans to spend two weeks next fall watching kokanee make love.
He’s not a fish voyeur, but an Okanagan University College biology professor who wants to enhance the annual spawning run along the shores of Okanagan Lake.
“We know quite a bit about creek-spawning kokanee., but we really know very little about shore-spawners,” he said Saturday.
Dill, 52, has a $1,000 grant from the university college’s new research fund to conduct his study into the shore-spawning variety of landlocked salmon.
“I’m an animal behaviorist with fish my main organism. I’ll be looking basically at their behavior to see what the difference is,” he said.
It could be environmental since Mission Creek and Okanagan Lake bottoms are quite different, he said, or it could be genetic.
“I will try to determine what happened in the past which separated these groups.”
Although hundreds of thousands of dollars have been spent on the Mission Creek spawning channel for example, “we haven’t spent much money to determine if the shore-spawners have certain needs,” he said.
“There are so many people living on the shoreline of Okanagan Lake now that we could inadvertently damage their habitat. Docks could change the flow of water, increasing or decreasing silting which could affect spawning areas.”
An increase in Eurasian aquatic milfoil growth could affect water circulation and the movement of gravel on the lake bottom, he said.
Environment Ministry officials like biologist Bruce Shepherd began studying shore-spawning kokanee several years ago.
The kokanee population averages 250,000 with only 20,000-30,000 of those shore-spawners.
The latter spawn from Squally Point in the South Okanagan to urbanized Kelowna, Poplar Point in Kelowna to Whiskey Island in the North Okanagan, and on the Westside from Bear Creek Provincial Park to the North Arm.
“They are very, very different fish,” said Shepherd from his Kaleden home Saturday.
Shore-spawners keep their bright silver color, getting mottled at best, while the bodies of stream-spawners turn red and their heads turn green.
Creek-spawners pick a site, prepare it and guard it until they die while shoreline spawners appear to scatter their eggs and don’t guard them.
The latter also spawn at three years. Fifty per cent of creek kokanee are four-year-olds and the rest are three.
The shoreline variety spawn for five days in late October while creek kokanee spawn four to six weeks in September and early October.
“Shore-spawners seem to spawn in areas where there is a rip-rap shoreline, where there is coarse, sharp-edged rock six to eight inches (15-20 centimetres) across,” said Dill.
Dill began his preliminary work last fall by watching the spawning run from the shoreline in late October.
He may hire a co-op student from the water quality technology program to assist him. However, he still hasn’t figured out a better way to observe kokanee behavior than sitting on the shoreline.
“It’s going to be difficult. I want to disturb the fish as little as possible since it is an enhancement project, but I want to be able to take out individual fish to measure how big they are, for instance, to sample the fish without disturbing the rest.”
A professor in the OUC biology department for the past 16 years, Dill has researched salmon and trout behavior for the past 25 years, almost since he graduated from the University of B.C. with a master’s degree in 1965.