23 



waterfowl. Furthermore, while there is considerable overlap of 

 invertebrate species, larger fish such as striped bass, bluefish, 

 tautog, flounder, and cownosed rays forage much more frequently in 

 offshore eelgrass beds than beds in shallow embayments. Thus, the 

 ecological consequences of loss of eelgrass habitat will greatly depend 

 on the location of the bed. 



The depth that eelgrass grows depends on light availability. 

 Light availability is largely controlled by phytoplankton abundance and 

 algal epiphyte cover (mostly determined by nutrient loading and 

 flushing) and sediment resuspension (Dennison, 1987; Kemp et al., 1983; 

 Lee and Olsen, 1985; Orth and Moore, 1983b; Sand-Jensen and Borum, 

 1983). Figure 3 shows that light is less available to eelgrass in 

 poorly flushed embayments than on more exposed shorelines, and water 

 transparency is best near the southern and eastern shores of Buzzards 

 Bay, than the northwestern end which is not as well flushed, and has 

 moderate riverine and larger anthropogenic inputs. 



The absence of eelgrass in the north ends of embayments such as 

 New Bedford Harbor, Little Bay, Fairhaven, and Apponagansett Bay, 

 Dartmouth does not correspond to physiological limits of eelgrass growth 

 due to the low salinities or damage due to natural disturbances. 

 Because eelgrass grew in these areas in the past (Chapter 4) , alternate 

 explanations must account for the absence of eelgrass, such as toxic 

 pollution, sediment resuspension, or nutrient enrichment. 



