Not all the sediment found within the system is mineral 

 particles; a large percentage is organic, either as fecal pellets 

 composed of plankton which have passed through the gut of larger 

 organisms, or films and coatings of mucus and bacteria. The 

 composition and methods of breakdown and utilization of this 

 material at the base of the food web are critical issues for the 

 overall productivity of the Gulf of Maine. Buried organic-rich 

 sediment has produced natural gas accumulations visible in 

 seismic reflection profiles and possibly as seeps in pockmarks on 

 the seafloor. These phenomena are important clues to the 

 location and nature of past nearshore and estuarine environments. 



Studies of the sediment-water interface, the interaction of 

 benthic communities with the sediments, and the rate and nature 

 of sediment transport are all addressed within this report. In 

 the following paper, Belknap, Kelley and Robbins report 

 specifically on the complex mosaic of sediment types, which 

 reflects both relict distributions and modern sedimentary 

 processes, and suggest linkages to other benthic oceanographic 

 studies. 



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