. An ecological characterization of Coastal Maine (north and east of Cape Elizabeth) . (JvJWMNteBllOAf SOBSySTEW) ;BUBLlTTO,RAL,:ZONe i N Wi, .Sl/BTi 0 m S I^.) PROTECTED AREA INCREASING EXPOSURE- EXPOSED AREA' Figure 5-36. Comparison of the boundaries of the physical intertidal zone and the littoral (biological intertidal) zone with increasing exposure to wave action (adapted from Lewis 1964). 10,382 acres (4203 ha; 15%), 10,709 acres (4336 ha; 16%), and 6820 acres (2761 ha; 10%), respectively. The relative physical stability of the subtidal environment allows for the establishment of
. An ecological characterization of Coastal Maine (north and east of Cape Elizabeth) . (JvJWMNteBllOAf SOBSySTEW) ;BUBLlTTO,RAL,:ZONe i N Wi, .Sl/BTi 0 m S I^.) PROTECTED AREA INCREASING EXPOSURE- EXPOSED AREA' Figure 5-36. Comparison of the boundaries of the physical intertidal zone and the littoral (biological intertidal) zone with increasing exposure to wave action (adapted from Lewis 1964). 10,382 acres (4203 ha; 15%), 10,709 acres (4336 ha; 16%), and 6820 acres (2761 ha; 10%), respectively. The relative physical stability of the subtidal environment allows for the establishment of diverse, highly organized communities. Ecological factors that affect the biota sometimes are quantitatively different in estuaries than in marine systems. Since the biota present in the brackish waters of estuaries are usually of marine origin, in order to survive they must physiologically adapt to estuarine conditions, such as reduced or highly variable salinities and temperatures. Areas that have greatly reduced and/or variable salinities have the fewest species (see "Estuarine Unconsolidated Bottoms" below). In subtidal subsystems tidal currents that carry suspended sediments and detritus are an important component of the subsystem. Estuarine productivity is dependent largely on attached macroalgae, macrophytes, benthic diatoms, and land-derived detritus, whereas marine systems are dependent largely on phytoplankton productivity. In general, pollution loads are greater in estuarine areas than in nearby coastal waters because of their higher human populations. Estuarine organisms generally are more adaptable to a wide range of environmental conditions and are more tolerant of perturbations than their marine relatives. Indeed, some of the species characteristic of upper estuarine areas are also characteristic of polluted water (Boesch 1973). Increased nutrient levels in estuaries due 5-77 10-80
Size: 4995px × 1001px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorusfishandwildlifeservice, bookcentury1900, bookcollect
