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Shoreline ecology

Shoreline ecology

Picture illustrating an ecological functions - large woody debris and light energy
There are numerous ecological processes and functions -- large and small, fast and slow -- operating in an ecosystem. These processes are influenced by both human activity, such as shoreline armoring and septic systems, and natural events such as windstorms, floods, earthquakes, and landslides.


The 10 key landscape processes outlined below -- both marine and freshwater -- are important to the vitality of Pacific Northwest coastal watersheds. Ultimately, they help to assess the value of shorelines and direct the management of shorelines.

For example:

  1. Erosion of a beach or bluff affects how sediment and woody debris reach the shoreline.
  2. Sediment and woody debris influence shoreline structures such as sand spits and mud-bottomed lagoons)
  3. The structure in turn dictates how a shoreline functions as habitat for fish and wildlife spawning, rearing, migration, refuge, or as a protective (or risky) area for development.

Shoreline ecological functions - what are they, why are they valuable?

  • Hydrologic cycle - how water moves can change everything;
  • Large woody debris - trees, roots, and branches deposited on beaches and in and along streams and rivers;
  • Light energy - light levels from shoreline vegetation or artificial lighting at night;
  • Nitrogen - alteration in nitrogen levels change the ecosystem;
  • Pathogens - germs and parasites which infect and weaken living things;
  • Phosphorus - alteration in phosphorus levels change the ecosystem;
  • Sediment - erosion, movement, and deposition of silt and sand;
  • Tidal influences - engineered rivers, tide gates, culverts;
  • Toxins - pollutants that weaken or kill animal and plant life;
  • Wave energy - boat traffic, bulkheads, armoring, breakwaters, docks.

For more information about shoreline management in King County, please contact Laura Casey, environmental scientist, Department of Local Services.