Shuswap nation takes action to improve local fish populations

Shuswap Creek before (inset) and after culverts removed (Photos by Larry Halverson)

In a forward-thinking initiative, the Shuswap first-nation community has taken action to improve the passage of fish from the Shuswap Creek, just north of Invermere, into the Columbia River. The creek runs through the Shuswap Reserve and a drainage culvert had long ago been constructed to protect an old road that runs alongside the railroad tracks. Since the road was no longer in use, the culvert was removed, thus allowing the fish to once again travel freely from the creek to the river.

Photo by Larry Halverson

This may appear a trivial thing to many, however it is important to note that such a seemingly small correction can make a world of difference to the ongoing health of our local fish populations. Fish, along with a host of other creatures that live in our rivers and lakes, form a complex web of life that is essential to the plants and animals that live on their shores — thus the health of one species determines the health and well-being of all others.

On a larger scale, Parks Canada has recently been taking a look at the culverts in our mountain national parks. Many of the main roads and highways through the parks intersect rivers and streams that facilitate the movement of fish populations in those areas. Because it is critical that fish are able to freely travel along these waterways to find food, mates, good spawning grounds and safe places for their young to grow, large culverts have been constructed to carry the flow of water under the roadways and to enable the fish to ‘cross the road’, so to speak.

In 2006, Parks Canada biologists assessed the condition of 600 of these culverts that cross under the roads and are intended to connect potential fish habitat in the seven mountain national parks -– Banff, Jasper, Kootenay, Yoho, Glacier, Mount Revelstoke and Waterton Lakes -– and discovered that more than two thirds of the culverts were either fully blocking or possibly blocking the movement of fish. This caused great concern to the Parks Canada staff who manage the aquatic ecosystems in those areas and who understand that a poorly functioning culvert can stop fish from reaching key parts of their habitat, possibly resulting in lower numbers, fewer species and less genetic diversity to keep the populations healthy.

One of the obvious causes of concern is that culverts can and do become blocked over time with branches, sticks and stones. Clearing them of the accumulated debris will not always fix the problem, however, since there are also other reasons why fish may not be able to reach their preferred areas through culverts.

For instance, most fish are sprinters and a long stretch of culvert with no resting place inside the culvert can easily tire the fish as they move from one side of the road to the other.

Fast-moving water through a narrow culvert can also be a difficult experience for fish, discouraging them from using this method of travel.

Some culverts are constructed to ‘hang’, creating artificial waterfalls that species which don’t jump, such as the whitefish for example, would not be able to navigate.

Also, during dry periods a very wide culvert may spread the already small amount of water into a layer that is too shallow for the fish to swim through.

Sometimes, perhaps due to blockage by branches or rocks outside of a culvert, the water flow is diverted around the culvert and thus the fish cannot reach their destination.

According to Parks Canada aquatics specialist, Shelley Humphries, the condition of the culverts is one of supreme ecological importance in our mountain parks. Parks Canada is undertaking to identify the 20 top-priority culverts and to repair at least 10 of them (as funds permit) in a 4-year ‘Restoring and Reconnecting Our Waters Action on the Ground’ project. For more information about the project, see http://www.pc.gc.ca/pn-np/ab/jasper/natcul/aqua-connect.aspx .