Figure 9. Ascophyl lum nodosum (knotted wrack) growing at the base of Spartina stems 

 in a creekbank marsh. Photo by J.M. Teal, Woods Hole Oceanographic Institution. 



greater biomass than S. alternif lora . No 

 good measure of the production of these 

 species at Great Sippewissett is 

 available. Ascophyl lum does disappear 

 rather rapidly in spring, suggesting that, 

 at the very least, it is contributing to 

 the detritus food web on the marsh. There 

 is abundant evidence that the green algae 

 are preferred food items for a number of 

 detrital-algal feeders such as snails 

 (Gieselman 1981). Ulva and Enteromorpha 

 are also eaten by brant and some ducks. 



Microscopic algae--mostly diatoms, 

 and green and blue-green algae (the latter 

 now usually classified as bacteria)--are 

 abundant on the surface of the salt marsh. 

 Algal mats may be the dominant vegetation 

 on recently formed sand flats that will 

 subsequently be invaded by S. 

 al terni flora . These mats are even more 

 abundant at higher elevations than in the 



regularly flooded parts of the marsh. 

 According to Blum (1968), the algae found 

 under tall, creekbank Spartina in 

 Massachusetts are mostly diatoms. The 

 shorter grass form supports filamentous 

 types of a variety of algal species: on 

 the mud surface are mostly blue-green 

 bacteria and growing up the lower parts of 

 the grasses are the blue-green Symploca 

 and the chrysophyte Vaucheria . In late 

 winter, early spring (Blum 1968), and 

 early summer, before grass growth shades 

 the mud surface (Van Raalte et al. 1976), 

 there are conspicuous blooms of 

 filamentous greens and blue-greens on the 

 mud surface, even under what will be tall 

 grass. In Georgia, Pomeroy (1959) found 

 mostly pennate diatoms (but also other 

 algae such as green flagellates and 

 dinoflagel lates) in low, wet sediments. 

 Blue-greens were found especially in late 

 winter and early spring. 



15 



