Aerial photo of Eagle Cove
(© Washington Dept. of Ecology)

Eagle Cove, located on the southwest coast of San Juan Island, encompasses several distinct intertidal habitats, including a sandy beach, a large rocky promontory, and small patches of loose cobble.   Each habitat has a unique assemblage of marine invertebrates, which contributes to the overall high diversity of the site.

Our goal in these pages is to document the diversity of invertebrates that live at Eagle Cove and to explore how they are able to survive and reproduce given the conditions presented by each habitat. We used special techniques to collect animals that live between sand grains, sampled transects through zones of the rocky intertidal, looked in tidepools and crevices, sifted through the eelgrass, and rolled boulders on the cobble beach. We found a wide variety of invertebrates within and among these habitats, as summarized in a master species list for the field site.

We also organized this diversity with the use of four functional themes: feeding , locomotion , reproduction , and protection . Invertebrates commonly found in each habitat employ a number of mechanisms to accomplish these four life tasks, allowing them to tolerate and thrive in the harsh conditions of the intertidal.