May 08, 2004
Provided and copyright by: Sherry Peruzzi
The photo above showing an eastern vernal pool in Ellicott City, Maryland was taken in early April of 2004. Vernal pools, also termed ephemeral wetlands, temporary puddles, disappearing ponds, springpools, or seasonally-ponded isolated wetlands, are contained basin depressions lacking a permanent above ground outlet. While they contain water during the spring and early summer, many dry out by fall. They're an important part of the ecosystem.
Only specialized plants and animals that are adapted to this cycle of wetting and drying can survive in vernal pools over time. Certain species that breed only in vernal pools are called "obligate species," and their presence indicates that the pond is indeed vernal in nature. Obligate animal species include the Wood Frog; a variety of salamanders; and the Fairy Shrimp, a tiny crustacean. Many other species use vernal pools as well, but the obligate species depend on them.