44 



APPENDIX E 



Artificial Keys to the Systems and Classes 



Key to the Systems 



1. Water regime influenced by oceanic tides, and salinity due to ocean-derived salts 0.5"/oo or greater. 



2. Semi-enclosed by land, but with open, partly obstructed or sporadic access to the ocean. Halinity wide-ranging 



because of evaporation or mixing of seawater with runoff from land ESTUARINE 



2. Little or no obstruction to open ocean present. Halinity usually euhaline; little mixing of water with runoff 



from land 3 



3. Emergents, trees, or shrubs present ESTUARINE 



3. Emergents, trees, or shrubs absent MARINE 



1. Water regime not influenced by ocean tides, or if influenced by oceanic tides, salinity less than 0.5"/oo. 



4. Persistent emergents, trees, shrubs, or emergent mosses cover 30% or more of the area PALUSTRINE 



4. Persistent emergents, trees, shrubs, or emergent mosses cover less than 30% of substrate but nonpersistent 



emergents may be widespread during some seasons of year 5 



5. Situated in a channel; water, when present, usually flowing riverine 



5. Situated in a basin, catchment, or on level or sloping ground; water usually not flowing 6 



6. Area 8 ha (20 acres) or greater lacustrine 



6. Area less than 8 ha 7 



7. Wave-formed or bedrock shoreline feature present or water depth 2 m (6.6 feet) 



or more lacustrine 



7. No wave-formed or bedrock shoreline feature present and water less than 2 m deep . palustrine 



Key to the Classes 



1. During the growing season of most years, areal cover by vegetation is less than 30%. 



2. Substrate a ridge or mound formed by colonization of sedentary invertebrates (corals, oysters, 



tube worms) REEF 



2. Substrate of rock or various-sized sediments often occupied by invertebrates but not formed by colonization 



of sedentary invertebrates 3 



3. Water regime subtidal, permanently flooded, intermittently exposed, or semipermanently flooded. Substrate 



usually not soil 4 



4. Substrate of bedrock, boulders, or stones occurring singly or in combination covers 75% or more of the 

 area rock bottom 



4. Substrate of organic material, mud, sand, gravel, or cobbles with less than 75% areal cover of stones, 

 boulders, or bedrock unconsolidated bottom 



3. Water regime irregularly exposed, regularly flooded, irregularly flooded, seasonally flooded, temporarily 

 flooded, intermittently flooded, saturated, or artificially flooded. Substrate often a soil 5 



5. Contained within a channel that does not have permanent flowing water (i.e., Intermittent Subsystem 

 of Riverine System or Intertidal Subsystem of Estuarine System) streambed 



5. Contained in a channel with perennial water or not contained in a channel 6 



6. Substrate of bedrock, boulders, or stones occurring singly or in combination covers 75% or more of 



the area rocky shore 



6. Substrate of organic material, mud, sand, gravel, or cobbles; with less than 75% of the cover consisting 



of stones, boulders, or bedrock unconsolidated shore 



1. During the growing season of most years, percentage of area covered by vegetation 30% or greater. 



7. Vegetation composed of pioneering annuals or seedling perennials, often not hydrophytes, occurring only at 



time of substrate exposure 8 



8. Contained within a channel that does not have permanent flowing water STREAMBED (vegetated) 



8. Contained within a channel with permanent water, or not contained 



in a channel unconsolidated shore (vegetated) 



