It’s been a crazy summer for our lab with multiple projects getting off the ground. One of the big ones of course was this fish tracking project on Ston(e)y.
We got onto the water at the end of May, about a week after the big storm hit. We owe a huge thanks to Brent Whetung for providing temporary boat and equipment storage on the lake, and the use of his boat launch. We spent early June deploying the array of 60 underwater acoustic telemetry receivers (the fish ‘listening stations’), which provide full coverage of Stoney and Upper Stoney, and extend part of the way down into Clear Lake. It was kind of a nice time to be on the lake, because we mostly had it to ourselves – is was very quiet other than the distant sounds of chainsaws. The first week we were there, the hydro crews were all over the lake.
Some pictures and video clips of receiver deployment work are below. The receivers are suspended off the bottom, but everything including the floats is at least six feet below the surface. These receivers will be able to detect our tagged fish if they swim within ~500m of a receiver, although detection ranges can vary a lot depending on conditions – it is not uncommon with this technology for fish to be picked up from 1-2 km away. The fish are sending out their signals every 2 minutes, so they only have to swim within range of the receiver for 10-20 minutes and we have a good chance of detecting them. When we pull up the receivers next spring for downloads and battery changes, we’ll start to get a sense of the behaviour and habitat use of the fish in the system.
Speaking of fish, we also got started on tagging a few fish in June but were cut off by the water temperatures getting too warm. In total we tagged 18 fish – a mixture of walleye (pickerel), yellow perch, and smallmouth bass (pictures below). Warm water temperatures are bad news for fish health and survival when it comes to catch-and-release, although the effects of temperature vary a lot among species. Because the tags (transmitters) are expensive, and because the 3-min surgery adds extra stress, we are focusing our tagging on when water temperatures are cool to ensure fish recover quickly and go on to live for a long time. The tags we’re putting in these fish will last for 3 years in the case of the larger animals, and about 1 year for the mini tags we’re putting into perch. If tagged fish are harvested, the tags can be returned to us a re-used (tagged fish are safe to eat).
We plan to be back out in early fall to do some more tagging, and expect spring 2023 to be our big tagging effort where we’ll get the rest of our tags out. We’re still in need of funding to purchase more transmitters for 2023 so we can keep the project going, if you’re interested in donating please follow this link! https://mycommunity.trentu.ca/tarpgive
And get in touch with me if you have questions.
Graham
Video (above) showing the team lowering an acoustic receiver (the cylindrical black thing) into the lake on a calm day in early May, near Ship Island. The big orange float sits 6-10 feet below the surface, and keeps the receiver off the bottom, listening for tagged fish to swim by.
Photo (above) showing underwater shot taken from a DFO underwater drone (that's its claw you can see), looking down at one of our receivers. This receiver setup is designed for shallow areas, where the receiver sits inside a white PVC tube that is embedded into the concrete anchor. A small yellow float suspended off the anchor helps us spot the receiver.
The photos above show (top) Dr. Brownscombe and his assistant Amanda doing surgery on a walleye in Stoney Lake. The fish (sutured incision shown in 2nd photo) is now swimming around the lake, being tracked by our receivers.
Photo (above) of Dr. Raby with a smallmouth bass in Upper Stoney, ready to be released moments after being surgically implanted with a 3-year acoustic transmitter. This and the other fish that have been tagged so far were all caught by angling.