39 



that most seeds land near the beds that produced them, and the 

 contribution of seeds by the existing beds in Waquoit Bay are negligible 

 where the seed profile cores were taken. These results are also 

 consistent with exponential declines in seed densities observed in wind 

 dispersed seeds from trees (Sharpe and Fields, 1982) . 



All the cores documented major fluctuations in eelgrass abundance 

 in the past reflecting local fluctuations in abundance (Fig. 3) . 

 Because the cores taken in Waquoit Bay were all taken from stable 

 environments, analyzed in more detail, and had more replicates, they 

 will be discussed first. 



Waquoit Bay 



The cores from the Waquoit Bay transect (WB1-WB3) each showed 

 three major peaks (B-D) in eelgrass abundance, separated by periods when 

 eelgrass was absent (Fig. 3, WB2 not shown). The depth of each these 

 peaks was progressively deeper along the transect toward the Quashnet 

 River and eastern shore, indicating higher rates of sediment deposition 

 from either of these sources. Biogenic depositional markers demonstrate 

 that these three peaks are identical. Three major mortalities of bay 

 scallop Argopectin juveniles between peaks B and C occur in the three 

 cores (S's in Fig. 3). For example, in the 31.5-33.0 cm section in core 

 WB2 (117 cm^) , 42 valves of Argopectin juveniles were found that lacked 

 signs of predation. Furthermore the snail Bittium alternatum is 

 abundant on the bottom of Peak B and top of Peak C on all three cores, 

 with densities exceeding 3 Bittium per cm^ in some sections. A large 

 population of the mud snail Nassarius sp. appear in eelgrass peak D of 



