Causes and Effects of Shoreline Erosion
A little science…what we can’t see
Eroded materials from your shoreline are basically particles of silt, sand and clay. When it becomes slow moving, it loses its ability to carry the heavier particles and they settle on the bottom, causing what is known as sedimentation. Sedimentation can then result in increased turbidity (murky water), the formation of deltas in rivers and streams, channel clogging, and increased chance of flooding due to lack of water movement.
When water is turbid, less sunlight can infiltrate water, beginning the upset that disturbs the biological balance for aquatic life. Aquatic plants and algae are reduced in growth, in turn diminishing the amount of food available to fish and other forms of aquatic life. Some fish (Northern pike and trout) use their sight to feed and turbid water makes it more difficult for them find food.
Sedimentation will affect bottom dwelling organisms like clams and caddis fly larvae by burying them too deeply to survive. Gravel and pebbles that are friendly to stoneflies and some species of mayflies may be buried in sediment, rendering the bottom unfriendly to these creatures as well. Fish species like walleye, trout and bass that use the same gravel and pebbles as their favourite spawning beds will also be affected as their reproductive sites are destroyed.
The Human Cost … what we can see
One of the potential impacts to humans when turbidity of water increases is the treatment of our drinking water. It becomes more difficult and costly, as sophisticated systems will be required to properly treat and clear the water of sedimentation. Murky water also makes waterfront property less attractive for all the water activities we enjoy at the lake like swimming and boating.
Causes of Shoreline Erosion
Here are some of human causes of shoreline erosion. We can now examine our own properties and then try to find a better balance by remedying what we can.
- Removal of trees, rocks and other vegetation from the shoreline to build a structure or a pathway to the water.
- Removal of vegetation to improve the view – or just to tidy up Mother Nature.
- Building obstructions like docks in streams that changes water pathways and speeds around them, influencing the natural erosion.
- Installation of drainage systems that do not include the use of baffles to reduce the flow of water.
- Use of watercraft of any kind for any purpose (skiing, wake boarding) at too high a speed (anything over 10 km/hr) and too close to shore.
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