Page 18 - 2021PSF-ResilientCoastsForSalmon-NewLogo-Primer-Web
P. 18
Photo by: Mitch Miller
Chapter 4 – Natural Coastal Processes: How Shorelines Work
We often think of our beautiful coast as static, but it is in fact always changing . Tides ebb
and flow, and seasons change . Sediments, rocks and debris are constantly moved around
by wind, currents and waves through the processes of erosion and deposition . The coastal
landscape, including the presence of human-made structures and alterations, influences
how these processes play out and has a tremendous influence on the habitats of our rich
and diverse coast .
Our Dynamic Coast
The movement of sediment affects the shape and
morphology of the beach, and the suitability of Photo by: Sarah Cotter
the habitat for various species . For example, Pacific
sand lance and other forage fish species have
very particular requirements for their spawning
grounds . They only spawn on parts of the beach
where the water reaches at high tide and where
the gravel is of a particular size . Sources of sedi-
ment such as naturally eroding coastal bluffs as
well as rivers and streams provide sediment that
creates and maintains beaches . Healthy beaches
exist in a balance of erosion and deposition, where
both processes occur simultaneously .
17
