Fish Trapping Insights

One of the activities that we get involved with is trapping juvenile fry and trout in the Stoney Creek watershed. We try to do this throughout the seasons as it gives us an idea of the numbers of fish in various locations, and we can see the sizes of the fish see how much they have grown and record the results.

One of the regions of the watershed where we set up traps is on Tributary 3A near Ashgrove Crescent. Here there is a small woods with mature cedar and  hemlock. This tributary has clean gravel that fish like to spawn in, and lots of cover from fallen logs which provides shade and protection. It supports a good population of salmonoids, cutthroat trout, and coho fry.

To trap the fish we use a Garr Trap, which is a cylindrical trap with two cone shaped inverted ends that allow the fry to swim in, but once inside, they can’t swim out. To attract the fry we need a bait,  so I usually double-up using both salmon roe from some of the fish that I have caught while angling for the table, and also some cat food. The cat food is tied into a small bundle which is suspended in the trap.

Ideally you want to place a trap in a good spot where you see lots of fish. A deep part of a creek or below an undercut bank are the most productive places to trap. Once the traps are placed in the creek, they are left overnight and picked up the next day. You hope it dosen’t rain as an increase in water flow will cause the traps to be pushed around, and the results are not good.

A Garr trap placed in the creek in a deep shaded pool

A Garr trap placed in the creek in a deep shaded pool

The fun part is going back the next day to retrieve the traps and see what the results are. A little spring clip opens the trap and the contents are gently transferred into a small bucket filled with creek water. Photos are taken of the fry in the bucket for identification. This give a top view of the fish. Then the bucket is dumped into a freezer bag to provide a side view picture and measurements. You can then identify the coho fry from the cuttthroat trout. The numbers of fish are recorded and the fish are then released unharmed back into the stream.

A catch from Trib 3A. Larger fish are cutthroat trout and smaller fish are coho fry.

A catch from Trib 3A. Larger fish are cutthroat trout and smaller fish are coho fry.

Trapping the fish enables us to see how healthy the watershed is how well the fish develop and grow during the season.

Get in touch with us to come experience the creek for yourself and to find out more!

On behalf of John, our resident trapper.