Figure 6. — Vertical temperature sections (°C) for the Gulf 

 of Maine between Bar Harbor, Maine, and Yarmouth, 

 ™ D 12 Nova Scotia, summer 1976. 



The surface salinity (Fig. 14) varied throughout the 

 sampling period with no distinct seasonal characteris- 

 tics. An overall increasing trend occurred through the 

 sampling period. In most cases, the salinities were higher 

 in the central gulf waters than in coastal waters. The 

 salinity along the study track increased through sum- 

 mer 1975, reaching a peak in October. After October, 

 central gulf and Nova Scotian waters rapidly decreased 

 (0.57.,/month) into November and December, while 

 Maine coastal waters maintained a slower rate. In 

 December the salinity in Maine waters dropped sig- 

 nificantly (0.67„); the lowest values occurred in Janu- 

 ary, followed by an increase into spring. Both Nova 

 Scotian and central gulf waters maintained a steady in- 

 crease of salinity through the winter, with peaks in 

 March for central gulf waters and in April for coastal 

 Nova Scotian waters. The gulf waters fluctuated through 

 the spring, with a rise into summer 1976. Salinities con- 

 tinued to increase through the summer and fall, with 

 values about 1%. higher than in 1975. 



DISCUSSION 



The Gulf of Maine transect can be divided into five 

 areas: coastal Maine (offshore to 100 m), coastal Nova 

 Scotia (offshore to 100 m), central surface waters (above 



50 m), central middepth waters (50-150 m), and central 

 bottom waters (deeper than 150 m). Each area showed 

 distinct characteristics and interactions with the sur- 

 rounding environment. 



Coastal Maine Waters 



Coastal Maine waters underwent a warming trend 

 from March through September with development of a 

 weak thermocline through the summer months. The 

 thermocline broke down in the fall, with cooling from the 

 shores outward through January. Maximum tempera- 

 tures were reached in September and minimum tem- 

 peratures in January. 



Coastal Nova Scotian Waters 



Coastal Nova Scotian waters had homogeneous con- 

 ditions throughout the sampling period. The warming 

 trend existed from April through September, with bot- 

 tom temperatures 0.5° to 1.5°C warmer than coastal 

 Maine. The cooling trend proceeded slowly through the 

 fall, accelerated through the winter, bringing minimum 

 temperatures by March. The historical means exhibit 

 similar seasonal development; however, they show a 

 summer thermocline near the Nova Scotian coast which 

 was not present in 1975 and 1976. 



