A variety of fish commonly are found in subtidal rock bottom habitat. These 

 include the American eel, the sea raven, the sea snails, the snakeblenny, the 

 rock gunnel, the ocean pout, and the redfish. 



Subtidal aquatic beds . Aquatic plant beds in Maine's coastal marine and 

 estuarine systems are either eelgrass or kelp. Preliminary NWl data indicate 

 that aquatic beds comprise 4% of subtidal bottom in the marine system and 2% 

 of the subtidal estuarine system. What is known of kelp beds in Maine is 

 discussed under "Rock Bottom" above, because these beds are indigenous to rock 

 bottoms . 



Eelgrass beds are found in shallow subtidal areas of the Maine coast (Timson 



1977) and are increasing in areal extent since their virtual disappearance in 



1931 as a result of a "wasting disease" (Phillips 1974). In Maine, eelgrass 



colonizes mostly muddy substrates, ranging from muddy gravels to pure mud, and 



is found at levels from mean low water to several meters deep. Colonization 



on gravel or sand surfaces is patchy or nonexistent (Tutin 1938). The 



criterion for eelgrass colonization appears to be protection from strong wave 



surges or current activity (Ostenfeld 1908), rather than substrate particle 

 size. 



Strong current velocities apparently prevent colonization by eelgrass, but it 

 has been observed in Puget Sound (Phillips 1974) that moderate currents may 

 enhance eelgrass growth. In Maine, eelgrass beds appear to flourish on broad 

 subtidal mud flats adjacent to flood- and ebb-dominated tidal channels. 



Information is lacking on marine subtidal aquatic beds in the 

 characterization area. These habitats have been studied elsewhere (e.g., 

 Chesapeake Bay), particularly in estuarine areas, and have been shown to 

 support dense and diverse assemblages of benthic invertebrates that are 

 different from those on surrounding bottoms (Orth 1973; Marsh 1973; and Thayer 

 and LaCroix 1971) . 



Eelgrass beds are abundant enough in coastal Maine to warrant detailed study. 

 These beds are a productive element of the coastal ecosystem that provide 

 habitat surface, nutrient regeneration, sediment stability, primary 

 production, and feeding areas for waterbirds. 



Kelp beds also provide detritus and habitat surface to estuaries. As with 

 eelgrass beds, the benthic invertebrate fauna of kelp beds is qualitatively 

 different from that of surrounding areas, especially in the plant holdfasts 

 (structures that attach them to rocks; Jones 1973). The uniqueness of the 

 fauna of kelp holdfasts has been confirmed in Maine by the authors. 



Subtidal aquatic bed areas (and intertidal aquatic bed and emergent classes at 

 high tide) are preferred habitat for most sculpins, red and white hake, 

 sticklebacks, mummichog, Atlantic silversides, cunner, and northern pipefish. 



The Intertidal Subsystem 



The intertidal subsystem is the area between extreme high and low tides. This 

 area is ecologically different from the subtidal area because of the daily 

 submersion and exposure of the substratum. The intertidal subsystem comprises 

 49% of the estuarine system in the characterization area. 



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