available. Least sandpipers, godwits, and semipalmated plovers feed on worms 

 in or contiguous to the low areas of salt marshes. Great blue herons feed on 

 fish in the salt marsh. 



The seed and root stocks of salt hay are eaten by ducks and geese. The dense 

 growth occasionally is used as nesting cover by waterfowl. Black ducks raise 

 young in this area of the marsh. Sharp-tailed sparrows, savannah sparrows , 

 and the spotted sandpiper nest in the salt hay marsh. Salt pannes in the 

 upper areas of marshes in Maine support large production of widgeon grass and 

 invertebrates which are important food for a variety of waterfowl and 

 shorebirds (Gore 1965; and Rasar 1968). 



Other species found feeding in and around the salt marshes are great blue 

 herons, long-billed marsh wrens, snowy egrets, Louisiana herons, and glossy 

 ibises (see chapter 14, "Waterbirds ," and chapter 16, "Terrestrial Birds," for 

 further information). The last three species are more commonly found in the 

 southwestern regions of coastal Maine. 



Detrital microbes play an important role in the production of food for 

 detritivores . On the coast of Maine the decomposition by microbes of 

 cordgrass is of great importance. Bacterial species (usually Cytophaga ) 

 contain active cellulolytic enzyme systems for consuming detritus, but very 

 little is known specifically about microbes because of their extremely small 

 size and relatively nondescript morphology. In Georgia, most microbial 

 activity in the salt marsh water column was associated with detrital particles 

 <3 MM in size (Hanson and Wiebe 1977). In salt marshes, microbial activity is 

 greatest at ebb tide and lowest at slack low water and high tide. In Maine no 

 studies have been made concerning the decomposition rates of detritus or the 

 microbial activity associated with decomposition. 



The usually high productivity associated with intertidal salt marshes and 

 particularly cordgrass is unique among natural systems. In - Maine, 

 productivity (annual biomass turnover) approaches 2 tons/acre (396g/m ). The 

 fact that much of this productivity then is transported to the estuarine water 

 column where it is a basic unit of the primary production upon which the 

 consumers and decomposers thrive is an added dimension of wetland 

 productivity. Although cordgrass is near the northern limit of its 

 distribution in Maine it appears to be no less productive than it is in the 

 South and mid-Atlantic States. The fact that salt marshes are small and 

 relatively uncommon in Maine in comparison with other States reinforces their 

 importance to Maine. Many consumers inhabit or frequent intertidal salt 

 marshes. Diverse birds and fishes are the most visible consumers, yet a host 

 of invertebrates species (insects, worms, molluscs and shellfish) also thrive 

 in salt marshes. People benefit from wetland productivity through commercial 

 and sport fishing, game hunting, and bird watching. 



In estuarine intertidal emergent salt marshes the physical environment 

 interacts with the biological community to form the basic characteristics of 

 the habitat. Energy flow, food webs, and nutrient and biogeochemical cycling 

 are examples of interaction between the biological and physical spheres. 



Symbolic representations of the major components and interactions of energy 

 flow in estuarine intertidal wetlands are given in figure 5-47 (see chapter 1 

 for a detailed description of energy and symbolic energy-flow diagrams). In 



5-127 



10-80 



