Dredging
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In order to maintain safe navigation, some channels and harbors require periodic dredging. Dredging is the process of excavating (or bringing up) material from an area (e.g., channel or harbor) with a dredge. Dredged material may include sediment, sand or silt carried as runoff from farms and forests or urban runoff and sewer overflows. While this process of dredging can be beneficial to aquatic ecosystems, it can also be detrimental.
The alteration of habitat and water quality may result through the removal of sediments. As a result, growth and reproductive capability of certain organisms can be compromised as well as the destruction of important spawning grounds for benthic communities and fish species, as documented by Rees (1980).
Dredging can also lead to anoxic conditions, which would cause aerobic species die-offs. Throughout these modifications to aquatic ecosystems, the potential exists that dredging may contribute to already declining fisheries as well as impact food web interactions.
Additional Resources
- U.S. EPA Partnership - the National Dredging Team
- U.S. Army Corpsof Engineers Great Lakes Dredging
- The Great Lakes Dredging team