occurring during spring, summer, and fall. While the greatest phytoplankton 

 activity occurs in spring, decomposer activity probably peaks somewhat later 

 (Novitsky and Passman, unpublished ) . Bacterial and fungal decomposers 

 generally are able to function at lower temperatures than phytoplankton. 



The geology of the Maine coast plays a significant role in controlling the 

 size and type of microbial populations. Dale (1974) reported that the 

 abundance of bacteria associated with sediments in an intertidal basin at 

 Petpeswick Inlet, Nova Scotia, Canada, was highly correlated with grain size 

 and other sedimentary properties. A fine silty or sandy bottom supported a 

 large bacterial population but a rocky or cobble bottom would be expected to 

 support a smaller population. 



The upper intertidal pools that are present in coastal Maine harbor unique 

 bacterial communities. Forsyth and his coworkers (1971) found that certain 

 salt-tolerant and "salt-loving" bacteria could be isolated from tidal pools 

 near St. Andrews, New Brunswick. They concluded that the increased salt 

 concentration in these pools, which results from evaporation, was a factor in 

 the natural selection of these "salt-loving" bacteria. 



BIOLOGICAL PRODUCTIVITY 



Primary Productivity 



Primary productivity, or the rate of input of photosynthetically-f ixed organic 

 carbon, is fundamental to the maintenance of marine biological systems. Net 

 productivity is that productivity stored as chemical energy after respiratory 

 demands have been met. The net production is available to primary consumers 

 (see "Food Webs" above). 



Primary production in nearshore marine waters is discussed in chapter 5, "The 

 Estuarine System." It is impossible to divide the discussion into estuarine 

 and marine systems, because nearshore marine (intertidal and shallow 

 subtidal) and estuarine production differ from production in deeper marine and 

 estuarine waters respectively. The major source of production in deeper 

 waters is phytoplankton, while in nearshore and estuarine waters macroalgae, 

 phytoplankton, and emergent wetlands are important in maintaining production. 

 The boundary, or depth, at which phytoplankton becomes the principal 

 component of production is unknown. 



Secondary Productivity 



Secondary productivity refers to the production of animal tissue, that is, the 

 growth of trophic levels above the primary producers. It is a measure of 

 energy flow through the various faunistic components of the ecosystem. 

 Unfortunately, no data exist on secondary productivity in the characterization 

 area . 



Biomass, or standing stock, is the weight or volume of animal tissue in a 

 given area or sample( e.g., per m or net tow of zooplankton) and it is often 

 used as a crude indication of productivity, on the assumption that biomass and 

 productivity are correlated. This is not necessarily true, of course, as a 

 community of large, long-lived molluscs will have a high biomass but low 

 productivity because the turnover rate is small. Conversely, a community 



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