The united insight of ancient and contemporary data into long-term changes in marine community composition

Have intertidal communities changed over the last few millennia? It is hypothesized that subsistence harvesting can dramatically alter both species composition and population structures of intertidal ecosystems. Here we use the united insight of prehistoric midden and contemporary intertidal composition to analyze temporal and spatial changes in intertidal communities of Sanak Island, Alaska. We demonstrate that some massive discrepancies exist between the relative abundances of species harvested prehistorically and today, and that middens imply an urchin-rich intertidal community existed in the past: a structurally and functionally distinct type of ecosystem in comparison to the algal-dominated communities that are present today.