Intertidal Biodiversity in the Gulf of Maine: Detecting Patterns of Diversity and Change

Epibenthic macroinvertebrate communities were examined at six rocky intertidal locations along the Maine shore. Sampled locations were distributed across nearly the entire coast of Maine from Kittery to Perry (43º N, 70º W to 44º N, 67º W) and were situated roughly equidistant from each other. All field sites were registered Critical Invertebrate Areas designated with this status in the 1970s by the Maine State Planning Office Critical Areas Program (1970-1987). Sampling of epibenthic macroinvertebrates was conducted by recording species observed on the substratum surface and under rocks during a random walk through the intertidal zone. Intertidal areas ranged from 6 to 12 acres and both sampling time and frequency of rock flipping were accordingly proportionate. Numbers of species (S) decreased south to north from 71 to 42.