Marine ecosystem analysis of Gouldsboro and Dyer Bays Maine In the early 1980s the National Oceanic and Atmospheric Administration (NOAA) initiated an ecosystem analysis of Gouldsboro Bay in eastern Maine as part of a planned marine sanctuary. The original report to NOAA by Walter H. Adey was not published after the sanctuary concept for Maine was abandoned. Because significant human related climatic and ecosystem changes are underway in the Gulf of Maine that report provides valuable baseline data and is included as the Appendix to this volume. After qualitatively describing the geological physical chemical and biogeographical features of Gouldsboro Bay and adjacent Dyer Bay we quantitatively describe the principal bay ecological communities with data collected during the 1981–1983 ecosystem assessment as well as additional measurements taken within the past decade. We then undertake a comparison of the primary productivity of these bays with the Google Earth Pro polygon tool to determine component areas. Benthic taxa are the dominant primary producers in both bays: rockweeds (primarily Ascophyllum nodosum with Fucus vesiculosus secondary) in the intertidal; Irish moss (Chondrus crispus with Fucus distichus secondary) as a near monoculture in the lowest intertidal (infralittoral); kelps (primarily Saccharina latissima Laminaria digitata and Agarum clathratum) in the rocky subtidal; and the angiosperm Zostera marina (seagrass) in soft bottom substrate. The rocky intertidal dominated by Ascophyllum with a specific productivity of 10.6 kg m2 year provides nearly one third of all bay productivity. Because of the proportionally greater shore length relative to area of Dyer Bay it has 45% greater productivity for its surface area than Gouldsboro Bay. Kelp has a specific productivity value of 7.2 kg m2 year and Zostera of 1.2 kg m2 year. The kelps provide approximately 20% of Gouldsboro Bay’s primary productivity and 35% of that of Dyer Bay. Zostera provides roughly 20% of total primary productivity in Gouldsboro Bay and 12% in Dyer Bay. With a primary productivity of 1.73 kg m2 year salt marshes provide only 3.7% (Gouldsboro) and 2.6% (Dyer) of total primary productivity. With a primary productivity of 0.06 kg m2 year plankton account for 23.8% of Gouldsboro Bay and 16% of Dyer Bay primary productivity.