Shoreline Disturbance

Natural vegetation along the shoreline of lakes and rivers plays a crucial role in protecting water quality, preventing soil erosion and preserving the ecological balance of aquatic environments.

Ninety per cent of all lake life is born, raised and fed inCows on the Shore the area where land and water meet. The shallow water and the first 10 to 15 metres of shore land forms a ribbon of life around lakes and rivers that is essential to the survival of many species. This rich and complex habitat supports plants, micro-organisms, insects, amphibians, birds, mammals and fish. The removal of vegetation, installation of retaining walls or dumping sand to create an unnatural beach, damage the natural shoreline and can decrease water quality.

Shorelines can also be damaged by livestock when they are allowed to graze at the waters edge. Livestock trample the shoreline, increasing erosion and sedimentation. Once in the water, they destroy aquatic vegetation and stir up mud and sediments.

Channelisation and Dredging

Channelisation is the practice of straightening a waterway to remove meanders and make water flow faster. It is used to control flooding and erosion, and improve navigation paths. When streams are channelised, the vegetation and cover is removed and replaced with concrete or stone edging, preventing the stream from meandering. This eliminates aquDredgingatic habitat, increases temperature and decreases available oxygen, which is extremely harmful for aquatic life.

Dredging is the removal or displacement of any material from the bottom of a lake or stream. It can harmfully alter, disrupt or destroy the areas in which fish live, feed and reproduce. Dredging can affect the food chain by removing micro-organisms that provide food for the lowest level of the food-chain. The process of dredging can also re-introduce contaminants into the aquatic system. As lake and stream beds are churned up through the dredging process, contaminants which have settled out of the water column are circulated back into the water. Even after dredging, the aquatic ecosystem can be negatively affected - as the sediments begin to settle they can smother aquatic plants and animals.

Adapted from Landowner Resource Centre: Preserving and Restoring Natural Shorelines; Agriculture and Agri-Food Canada: Managing Livestock in the Riparian Zone; and Fisheries and Oceans Canada: Fact Sheet - Fish Habitat and Dredging