ECOLOGY OF BUZZARDS BAY: An Estuarine Profile 



59 



suggests that the eastern shore, with its lower levels 

 of nutrient loading and river flow, may have higher 

 transparency and possibly better water quality than 

 the western shore. This finding is consistent with 

 the significantly lower levels of nutrients and phy- 

 toplankton productivity (Table 4.5) near Woods 

 Hole where Zoster a grows to 5.5 m versus the 

 maximum depth in the New Bedford-Fairhaven area 

 of 0.9 to 3.0 m. In general, however, the 3.6-m 

 contour encloses almost all of the potential inten- 

 sive growth area for Zostcra in Buzzards Bay 

 (Costal 988 a,b). 



Zostera covers extensive areas of the nearshore 

 of Buzzards Bay and forms a nearly continuous band 

 from Westport to Woods Hole. The area of exist- 

 ing beds is about 4.500 ha or about 8% of the 

 subtidal area of the bay. Correcting the area of the 

 beds for bare areas within the beds, the ac- 

 tual vegetated area is about 3000 ha (Table 4.6). 



As in the case for the maximum depth of growth, 

 the extent of theoretically habitable bottom actually 

 colonized appears to be related to anthropogenic 

 impacts. This is particularly clear in the case ofNew 

 Bedford Outer Harbor, Dartmouth, and to a lesser 

 extent Fairhaven, where only 0.3%, 1 8%, and 38%, 

 respectively, of the available area has beds (Table 

 4.6), and much of the total terrestrially derived nu- 

 trient load enters the bay. The potential sensitivity 

 of Zostera beds to nutrient loading (operating 

 through phytoplankton and epiphyte effects) has 

 served to make eelgrass a sentinel species for moni- 

 toring nutrient-related water quality of Buzzards 

 Bay (Buzzards Bay Project 1990; Costa et al. 

 1992). 



4.2. Intertidal 



4.2.1. Salt Marshes 



Salt marshes (Fig. 4.7) represent an important 

 component in the ecology of Buzzards Bay (Tables 

 1 . 1 and 4.5). Salt marshes occur in pockets all 

 around the border of the bay, including Little and 

 Great Sippewissett in West Falmouth, Allen's Pond 

 and Little River in Dartmouth, Weweantic in 



pa** 



Fig. 4.7. Aerial view of the Great Sippewissett Salt 

 Marsh, West Falmouth, Massachusetts. Photo by 

 B. Howes 



Wareham. along the Westport River, and Priest's 

 Cove and West Island in Fairhaven. Westport has 

 the largest area of salt marsh in the Buzzards Bay 

 system, primarily due to the presence of the 

 Westport River. In contrast, New Bedford has the 

 smallest area caused both by the physical structure 

 of the harbor as well as by large-scale develop- 

 ment that has occurred over the years. These tidal 

 wetlands within the bay system are typical of New 

 England marshes, generally forming behind protec- 

 tive barriers such as barrier beaches, or as narrow 

 fringing marshes in low-energy environments such 

 as circulation-restricted coves and embayments. 

 The diminished velocities of tidal water as it enters 

 these coves and embayments results in the deposi- 

 tion of suspended particles, ultimately resulting in 

 the establishment of sediments at an elevation within 

 the tidal range suitable for the colonization of marsh 

 plants. The absence of high-energy waves is 



