THE MOUNT DESERT REGION 35 



The belief that a region possessing such a variety of en- 

 vironmental conditions in a limited area, while situated on 

 the northern line of the transitional zone of the Austral and 

 the southern line of the Boreal region, should offer an excep- 

 tional opportunity for biological research was what caused 

 me to undertake this Survey. 



Only by studying a chart showing the depths, banks, and 

 adjacent coast lines can anyone appreciate fully the land- 

 locked character of the Gulf of Maine. The character of the 

 Maine coast is influenced mainly by the tides of the Bay of 

 Fundy and one might say with slight exaggeration that Mount 

 Desert Island lies just off its mouth. Test dredgings made in 

 Chalmers Bay north of the Moos-a-bec Reach showed a 

 marked difference in forms, particularly in the sea-weeds, 

 from an average haul in Frenchmans Bay. 



The climate of the Island has a July average of 65° F., a 

 January average of 24°F., and a yearly average of 43°F. 

 Our records show a 6-year average for the months of July and 

 August of 58° for the surface and 48^° for the bottom. The 

 annual precipitation is 43 inches, evenly distributed through- 

 out the year. 



On looking at the shores of this region, one is struck by the 

 marked difference in their heights, which range all the way 

 from mud flats to precipitous cliffs, one of them being the 

 highest headland on the Atlantic coast. 



The conditions of the inner bay differ from those in the 

 outer bay chiefly in respect to the force of the action of the 

 waves and the circulation of the water, the water of the inner 

 bay being greatly modified by the Porcupine Islands. In such 

 manner are the waters of the thoroughfare between Mount 

 Desert Island and Cranberry, Greenings and Suttons Islands 

 sheltered. 



Due to this and the nature of the rocks, there are no tide 

 pools on the inner side of the Porcupine Islands. On the 

 other hand, the tide pools on the outer side of the Porcupine 

 Islands, subject as they are to heavy wave action, are among 

 the best in the region and equalled only by the tide pools on 



