Malacologists have long recognized Seasonal Wetlands as habitat for members of the fingernail and pea clam family (sphaeriidae). Other invertebrates are also known to inhabit Seasonal Wetlands.
Waterfowl are known to frequent many of these pools, albeit sporadically. Wood ducks, mallards, black ducks, and occasionally great blue herons will stop, especially at those Seasonal Wetlands with growths of vegetation such as duckweed or abundant populations of mollusks. Thus, the presence of mollusks, duckweed residues, or other indicators of temporary pooling of water such as caddis fly cases, are indicative of the presence of a Seasonal Wetland.
With regard to floral characteristics, the typical plant communities usually associated with wetlands cannot reliably be used for Seasonal Wetlands. The presence of certain species of submergent or emergent vegetation generally indicates a wet condition that may go beyond the definition of a Seasonal Wetland. Vegetation more usually associated with a wet meadow may indicate the pooling of water for a time insufficient for a Seasonal Wetland. These conditions may indicate the presence of an Isolated Wetland or an area that holds standing water for a major part of the year.
Seasonal Wetlands are isolated depressions or closed basins which temporarily confine water during periods of high water table and high input from spring runoff or snow melt or heavy precipitation, and support populations of non‑transient macro‑organisms or serve as breeding habitat for select species of amphibians.
In the absence of those habitat functions, the areas should be considered as Isolated Wetlands. Seasonal Wetlands predictably fill up during the spring rains and snow melt, dry up during the summer, and may fill again during the fall rains. With few exceptions, a Seasonal Wetland is not considered temporary if the standing water does not disappear. The hydrological cycle may occasionally miss a year. In order to be considered a Seasonal Wetland the basin depression, in most years, will hold water for a minimum of two (2) continuous months during the spring and/or summer.
Shape: Seasonal Wetlands occupy shallow, cup‑shaped depressions in areas where flooding from nearby waterways or water bodies, where rising ground water or sidehill seeps may serve to fill them temporarily.
Size: Seasonal Wetlands are characteristically small; however, a given pool can vary in size from year to year depending on the amount of rainfall or snow melt. No minimum threshold size is indicated.