In the summers of 1966 and 1967, very low surface temperatures, about 11 C, and weakly stratified water occurred along the western coast of the Gulf of Maine at Cape Nedick, in the Sheepscot River, and off Vinalhaven Island at the mouth of Penobscot Bay. Moderately low temperatures, about 13 C, were found often between the islands of Casco Bay. These low temperatures indicate an active vertical mixing, associated with tidal currents, that transports water warmed at the surface downward and cold water upward.Where tidal mixing is reduced, offshore from Cape Ann and in the landward confines of Casco Bay, surface temperatures over 17 C and pronounced stratification occurred. When these high temperatures were observed off Cape Ann, the weather was sunny and calm, or a light wind caused very little mixing. Within Casco Bay temperatures of 17 C or more were observed during a period when fogs were prevalent, allowing heating in clear spells in the daytime and a minimum of cooling at night.
OBSERVATIONS ON THE DISTRIBUTION AND BREEDING OF SAGITTA ELEGANS
(CHAETOGNATHA) IN COASTAL WATERS OF THE GULF OF MAINE