19 



(New Bedford, Dartmouth, Westport) have substrate-eelgrass area ratios 

 higher than other towns in Buzzards Bay which range 1.5-2.5. These 

 higher ratios (e.g. 350 for New Bedford) can be explained in part by the 

 loss of eelgrass bed area that I report in Chapter 4. If the substrate- 

 eelgrass habitat area throughout Buzzards Bay equaled the mean ratio for 

 the less polluted towns (2.1), then there would be 15% more eelgrass 

 along the mainland portion of Buzzards Bay. This suggests that chronic 

 pollution in Buzzards Bay has already eliminated 15% of potential 

 eelgrass habitat. 



Discussion 



In Buzzards Bay today there are ca. 4500 hectares of benthic 

 habitat where eelgrass is a conspicuous biological component. When 

 corrections are made for percent cover of this habitat as apparent on 

 aerial photographs, as well as adjustments for unmapped area, there are 

 approximately 2900 hectares of eelgrass bed cover. 



In one sense, this is an underestimate, because this total does 

 not take into account the eelgrass indicated with a "+" on the maps or 

 other questionable areas. On the other hand, the eelgrass bed 

 dimensions reported here were largely based on photographs between 1974 

 and 1981, and documentation in Chapter 4 suggests that eelgrass cover 

 has declined in some areas and expanded in others in recent years. 

 Nonetheless, given these errors and omissions, as well as including 

 mistakenly identified submerged vegetation, this estimate of total 

 eelgrass cover for Buzzards Bay is probably accurate within 300 

 hectares. 



