Fish Passage Improvement

Improperly designed, installed, or maintained water-crossings have led to aquatic habitat fragmentation across Nova Scotia. Generally, the higher the degree of fragmentation within a watershed the smaller the overall fish population will be. The impacts of fragmentation on fish species are loss of spawning habitat, loss of food sources, inability to escape predation, inability to find thermal and other water quality refuges, and more.

There are estimated to be over 20,000 culverts in Nova Scotia. Assessment surveys routinely and conservatively estimate that 50% to 70% of all culverts are partial or full barriers to a variety of migrating fish. It has been estimated that 8% of new culvert installations are installed improperly causing barriers to fish passage as well. This is a significant problem to recreational fish populations that has been identified as a priority by the NSLC Adopt-a-Stream Program.

In an effort to address this issue, the NSLC Adopt a Stream program has developed low cost tools and techniques to address common culvert barriers. The most commonly used tool is known as the "outflow chute". This device backs water up through the culvert creating more depth and lower water velocities. The device is low-cost and easily installed by watershed stewardship groups. 

To date, NSLC Adopt a Stream and our watershed stewardship affiliates have completed over 75 fish passage improvements in Nova Scotia!