ALGAL VEGETATION OF THE YORK RIVER ESTUARY AND THE ADJACENT OPEN COAST OF SOUTHERN MAINE

A total of 72 seaweed taxa were recorded from the York River Estuary, Maine, including 29 Rhodophyceae, 19 Phaeophyceae and 24 Chlorophyceae . A synopsis of several distributional patterns is given, as well as f loristic comparisons of the York River with two nearby open coastal si tes in Maine (Cape Neddick and Sea Point) and 12 estuarine locations w ithin New Hampshire and northern Massachusetts In contrast to the Grea t Bay Estuarine System (New Hampshire/Maine) where coastal species occ ur upstream to approximately 8.5 miles, a relatively rapid attrition o f species occurs within the York River after 2-3 miles, presumably due to hydrographic variability, the dominance of saltmarsh habitats and reduced availability of rocky substrata. Overall, species composition within the York River compares favorably with several mid-estuarine en vironments within the Great Bay Estuary as well as saltmarsh habitats of the Hampton-Seabrook Estuary System (New Hampshire). Relatively few of the ''southerly'' taxa common to the Great Bay Estuary are present within the York River and Hampton-Seabrook Estuary, presumably becaus e of a lack of suitable habitat. Three floristic records of particular interest include the presence of Fucus vesiculosus megecad limicola f rom the York River Estuary, and the occurrence of Porphyra amplissima and Codium fragile ssp. tomentosoides from southern Maine.