A resource for shoreline property owners
The San Juan Islands have varied shorelines, and each shore type has a different ability to accommodate disturbance. Some are stable and robust; others are fragile and easily destroyed. Cumulative impacts can result from individually minor but collectively significant actions taking place over time. This section describes the physical and biological attributes of our nearshore ecosystem.
Nearshore refers to the land and sea connection. It encompasses the upland extent of the shoreline at least 200 yards from the high water line and down into the water to a depth where sunlight penetrates known as the “Photic Zone”.
The nearshore environment surrounding our islands is providing essential habitat to a multitude of marine species, including our endangered Southern Resident Killer Whales.
SRKW are selective eaters relying almost exclusively on Chinook salmon. The 22 local Chinook populations, which are threatened, rely on our forage fish stocks of Pacific herring, surf smelt and sand lance as well as terrestrial insects. Our nearshore environment provides the habitat necessary to the spawning and rearing of these forage fish species.
Rocky Shoreline
- Most of our shoreline in the San Juan Islands is rocky and is resistant to erosion.
Rocky shorelines often support kelp beds and rockfish habitats.
- Provides inner-tidal habitat for an abundance of species: mussels, limpets,
snails, chitons, barnacles, sea stars, sea cucumbers, urchins, anemones and
octopus.
- The native vegetation that grows along these shores filters run-off,
and because the soil is often
shallow it is essential in maintaining healthy soil densities and water quality.
- Maintaining native vegetation also supports the near shore ecosystem because it provides
habitat for terrestrial, or land-based, insects. These insects end
up in the water and become an essential component to the diet of juvenile salmon.
What is important about Kelp?
- A multitude of kelp species grow along our rocky shorelines.
- Our abundant bull kelp grows in underwater forests to depths of 60 feet.
- Kelp beds are both a protective canopy and an abundant feeding ground.
- They are utilized by juvenile and adult rock fish, ling cod, urchin, crab, sea stars, sea cucumbers, octopus, seals and salmon.
- Kelp beds decrease the force of waves along the shoreline and provide an essential place of respite to sea birds, seals, and salmon.
- Kelp needs light and clear waters to grow.
Bluff or Eroding Bank
- Bluffs and banks are composed of many layers of glacial materials such as sand, gravel and clay.
- Erosion is a natural ongoing process with bluffs and steep banks. The rate of erosion varies dependent upon upland drainage, vegetation and exposure to wave action.
- Because of their rare occurrence throughout our county it is essential to allow those that exist to function properly. Our beaches are dependent upon bluffs and eroding banks to supply sands and sediments into the system.
- The sediments from bluff and bank erosion travel via wave patterns and currents to continually feed the beaches throughout the islands.
-
More information on bluffs
Beaches
-
The beaches in our county are mostly comprised of mixed gravel and sand.
-
Many of our beaches are pocket beaches: isolated beaches along the rocky shoreline, contained by rocky headlands.
-
Sands and sediments from eroding banks and bluffs are transported by the flow of currents and wave action to continually build our beaches.
- Our beaches provide habitat for forage fish spawning and may support eel grass beds.
- Surf smelt and sand lance spawn on beaches with fine or course sands and pea gravels. They are sensitive to changes often resulting from shoreline alterations and development.
- Native vegetation is important for shoreline stabilization and erosion protection.
- Overhanging vegetation provides essential shading for forage fish spawning.
- Incubating eggs are susceptible to increases in temperature.
- Because it is common to have low tides during summer months vegetative shading is necessary to keep the waters and sediments cool.
- Studies have shown greater survival rates along shorelines with intact vegetation.
-
Though the water may chill our toes, juvenile salmon also rely on this vegetative shading to keep the temperatures cold in shallower waters.
Estuaries and Coastal Wetlands
-
Coastal wetlands and estuaries are rare and fragile environments in our County.
-
Where stream mouths reach our marine waters there is a mixing of fresh and salt waters, which provides a unique habitat niche. These estuaries are significant to juvenile salmon as they transition from a freshwater existence to marine waters.
-
Our coastal wetlands improve water quality by filtering sediments, excessive nutrients and toxic chemicals.
-
Estuaries and coastal wetlands support a vast and diverse array of wildlife including invertebrate species, fish, and migrating and resident birds.
-
Eelgrass beds often grow in these nearshore waters.
What's important about eelgrass?
-
Eel grass has been designated as a “key stone species”. This flowering plant provides essential breeding grounds and protective nurseries supporting the complex marine food web.
-
140 miles of eel grass have been documented in SJ County.
-
Pacific Herring lay their eggs on the blades of eel grass.
Courtesy Friends of the San Juans
-
There are two recognized spawning stocks of Pacific herring in our County, which use specific areas year after year.
- One utilizes the Westcott Bay region.
- One utilizes Mud & Hunter Bays (Lopez), West Sound & Eastsound (Orcas), and Blind Bay (Shaw)
-
Eel grass is highly sensitive to changes in light, temperature and sediment, which often accompanies shoreline development.
How do I get information about my parcel?
- San Juan County's parcel search
provides basic information and aerial views of your property.
- The Washington Department of Ecology's Coastal Atlas offers aerial views of
coastline properties and GIS information about vegetation and habitat, slope stability and a variety of other physical and ecological features.