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drift algae that accumulated because of nutrient loading. Sediment 

 suspension from topsoil runoff or boat propeller often contribute to 

 water transparency decline and loss of eelgrass (Brush and Davis, 1984; 

 Orth and Moore, 1983b). Even where sediment turbidity is high, however, 

 such as parts of Chesapeake Bay, attenuation of PAR by inorganic 

 particles is generally less than the combined effects of PAR absorption 

 by algal epiphytes and phytoplankton (Kemp et al., 1983). Nonetheless, 

 sediment resuspension from dredging and motor boat activity is prominent 

 in some local bays (pers. obser.), and may significantly decrease water 

 transparency. This phenomenon has not been quantified, but may be 

 locally important in affecting eelgrass distribution. 



In southern New England, eelgrass grows as deep as 6-12 m MLW in 

 clear offshore waters, but only to 1-2 meters in shallow bays with poor 

 water transparency (Costa, 1988 and below). Thus, small changes in 

 light availability to eelgrass populations, for whatever reason, may 

 result in larges losses of eelgrass cover. 



Drift algae 



Drift algae typically show conspicuous increases where nutrient 

 loading is high, and often accumulate in poor flushed bays in layers 

 exceeding 40 cm (Lee and Olsen, 1985; pers obs.) This accumulation may 

 smother shellfish (Lee and Olsen, 1985) and eelgrass (pers. obser.). 

 Locally, red algae such as Gracillaria, Agahrdiella, and Ceramium are 

 most abundant, often mixed with green filamentous algae such as 

 Cladophora. Many of these algae are specialized morphological varieties 

 of their species (Taylor, 1957) which grow and reproduce on the bottoms 



