Chapter 4 



The Marine System 



Authors: Bigelow Laboratories for Ocean Sciences 



The marine system is the largest and most ubiquitous aquatic system in coastal 

 Maine. Coastal Maine waters support many industries, including commercial 

 fishing, transportation, waste disposal, and recreation. They sustain diverse 

 food webs of organisms that directly and indirectly benefit people. 

 Ultimately, the marine system receives waters that pass through all other 

 systems in the coastal zone. This chapter will present some basic concepts 

 and data on the functions of the marine system. Such information is essential 

 if wise decisions balancing the various uses of the marine system are to be 

 made . 



The marine system is that area exposed to full-strength sea water (over 30 ppt 

 salinity) between extreme high water of a spring tide and the 300-foot (100 m) 

 depth contour. It is located along the shoreline in open embayments and 

 seaward of the headlands and encompasses the overlying water as well as the 

 substratum beneath the water (figure 4-1). 



The habitats encompassed by the marine system include the water column and the 

 major bottom substrata of unconsolidated sediments and rocky bottoms. 

 Unconsolidated sediments include cobble, gravel, sand, and mud, as well as 

 eelgrass or emergent wetland subhabitats growing on the sediments and streams 

 flowing over the sediments. Rocky substrata are bedrock or boulder with algal 

 beds (kelp) attached to the rock. The area between the tides (intertidal 

 zone) is ecologically different from the area that is submerged at all times 

 (subtidal zone), hence, the two zones and their habitats are discussed 

 separately here. 



The area of marine waters along the shoreline of the characterization area is 

 172,705 acres (69,921 ha; National Wetlands Inventory, preliminary data). The 

 acreage of marine waters between the embayments and 300-foot (100 m) depth 

 contour was not calculated by the NWI but amounts to more than the number of 

 acres inshore. The specific locations of the marine system in the 

 characterization area are depicted in atlas map 1. 



4-1 



10-80 



