Shoreline Habitat Classification

Marine, intertidal, boulder, protected, eulittoral

Many areas in the northern Puget Trough receive neither oceanic swell nor extensive wind fetch, but retain their rocky character due to steepness of the shore or currents that sweep away most sediment. Examples are the inside waters of the San Juan Islands, where there is not enough freshwater input for sites to be categorized as Estuarine. Siltation, desiccation, and temperature stresses all take their toll on rocky-shore organisms in these areas. Communities on tops and sides of boulders are similar to those on bedrock, but the spaces on the lower edges and beneath boulders provide additional  spatial complexity; these microhabitats tend to be shadier (and thus cooler) and less exposed to wave disturbance. Boulder habitats thus often have very high species diversity.

Class ID
8
Class name
Marine, intertidal, boulder, protected, eulittoral
Length
8.00
Primary substrate
Bedrock
Secondary substrate
Boulder
Tertiary substrate
Gravel
Substrate stability
Stable
Substrate key details
No sediment except surface siltation
Wave exposure
Protected, Very protected
Blue book classes
Marine intertidal rock: Semi-protected and protected
Map/survey site examples
Sites in inner San Juan Islands
Fish sampling sites

Diagnostic species
Fucus distichus
Mastocarpus papillatus
Nucella lamellosa
Littorina
Balanidae
Anoplarchus purpurescens
Gobiesox maeandricus
Oligocottus maculosus
Xiphister atropurpureus
Habitat classification system