PROVISION OF FISH AND AQUATIC INVERTEBRATE HABITAT1


Wetlands are widely recognized as important habitats for many species of fish and wildlife and there is a wide body of literature to support this claim (e.g., Mitsch and Gosselink 2007, Tiner 2005a). The assessment of potential habitat for fish and aquatic invertebrates is based on generalities that could be refined for particular species of interest by others at a later date if desirable. Regional and local variations will need to be accounted for on a watershed-by- watershed basis. The criteria selected below are useful for the Georgia coastal zone and many may be applicable nationwide, but they should be re-examined for each project area beyond the Georgia coast to ensure accuracy and completeness. Although focused on fish and aquatic invertebrates, wetlands identified as significant for these species are likely also significant for other aquatic-dependent animals such as muskrat, turtles, water snakes, and numerous amphibians.


For tidal areas, the assessment emphasizes estuarine wetlands, palustrine and riverine tidal emergent wetlands, unconsolidated shores (tidal flats), and intertidal oyster reefs. For nontidal regions, palustrine aquatic beds and permanently flooded and semipermanently flooded wetlands are ranked higher than seasonally flooded types due to the longer duration of surface water. Semipermanently flooded wetlands along permanent waterbodies may serve as fish spawning grounds during high flows. Many ponds (excluding wastewater ponds, for example) and the shallow marsh-open water zone of impoundments are identified as wetlands having moderate potential for fish and aquatic invertebrate habitat.


Shading by trees and tall shrubs moderates water temperatures for streams (Ghermandi et al. 2009, Wilkerson et al. 2006). Since water temperature is an important factor influencing fish use of streams as well as providing food (through leaf drop) for aquatic organisms that are an important part of the diet of juvenile and some adult fishes, forested and shrub wetlands along streams have been rated as moderate for fish and shellfish. The streamside wetlands also serve

as vital buffers that help maintain good water quality.


Other wetlands providing significant fish habitat or benefits to their habitat may exist, but are not identified. Such wetlands may be identified based on actual observations or culled out from site- specific fisheries information that may be available from other sources. Moreover, all wetlands rated as significant for the streamflow maintenance function are already considered vital to sustaining the watershed's ability to provide lotic aquatic habitat. While these wetlands may not serve as significant fish and shellfish habitat, they support base flows essential to keeping water in streams for aquatic life. Terrene outflow wetlands and Lotic basin wetlands along low order streams (e.g., orders 1-2 in Coastal Plain) often discharge cool groundwater to streams which keeps these streams cooler in summer. Such wetlands are important for providing summer refuges for some species.


For this function, the following relationships are used:

High

Estuarine Emergent Wetland (including mixtures with other types where emergent is the dominant class), Estuarine Unconsolidated Shore (not irregularly flooded type), Estuarine Intertidal Reef (oyster), Estuarine Aquatic Bed, Lacustrine Littoral semipermanently flooded or permanently flooded (excluding wetlands along intermittent streams), Lacustrine Littoral Aquatic Bed, Lacustrine Littoral Unconsolidated Bottom/Vegetated Wetland, Marine Intertidal Unconsolidated Shore (not irregularly flooded), Palustrine semipermanently flooded (excluding wetlands along intermittent streams; must be contiguous with a permanent waterbody such as PUBH, L1UBH, or R2/R3UBH or be a semipermanently flooded slough), Palustrine Aquatic Bed, Palustrine Unconsolidated Bottom/Vegetated Wetland, Palustrine Vegetated Wetland with a permanently flooded water regime, Palustrine Tidal Emergent Wetland (excluding S water regime), Ponds (PUBH… on NWI; not PUBF) associated with semipermanently flooded or permanently flooded Vegetated Wetland, Riverine Tidal Emergent Wetland, Riverine Tidal Unconsolidated Shore (excluding those with an S water regime), Riverine Tidal Aquatic Bed, Riverine Lower Perennial Aquatic Bed, Riverine Lower Perennial Aquatic Bed






Moderate

Estuarine Wetlands where Forested or Scrub-Shrub Wetland is mixed with Emergent Wetland, Lentic wetlands that are PEM1C (and contiguous with a waterbody), Lotic River or Stream wetlands that are PEM1C (including mixtures with Scrub-Shrub or Forested wetlands; and contiguous with a waterbody), Other Ponds and associated Fringe wetlands (i.e., one acre or larger; specify pond types: natural ponds, beaver ponds, and excavated or impounded ponds that are used for aquaculture and wildlife management), Lotic River Floodplain Basin Wetlands, Palustrine Tidal Forested or Scrub-Shrub Wetlands mixed with Emergent Wetland with seasonally flooded-tidal (R) or semipermanently flooded-tidal (T) water regimes








Note: Industrial, commercial, and wastewater treatment ponds should be excluded from this function.





1. This assessment is focused on wetlands, not deepwater habitats, hence the exclusion of the latter from this analysis, despite widespread recognition that rivers, streams, andlakes are the primary habitats for fish and shellfish.



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