According to the NJ Department of Environmental Protection (NJDEP) and Wikipedia, vernal pools are temporary pools of water that are without fish. This lack of fish enables the development of natal amphibian and insect species. Most pools are dry at least part of the year and fill in with the winter rains or snow melt. They are typically at their peak depth in the spring, hence the name “vernal”.
Vernal pools are confined wetland depressions, either natural or man-made, that hold water for at least two consecutive months out of the year and are devoid of breeding fish populations. Here in New Jersey, rural portions of the Highlands, Piedmont, and Coastal Plain landscapes are home to the majority of our vernal pools. These unique ecosystems provide habitat to many species of amphibians, insects, reptiles, plants, and other wildlife.
Vernal pools come in an array of forms: isolated depressions within upland forests, seasonally flooded meadows, floodplain swamps, abandoned gravel pits or quarries, and even derelict swimming pools. However, no matter what the structure or genesis of the pool is, all vernal pools either dry out completely or draw down to very shallow levels unsuitable for sustaining fish. Fish are highly predatory on amphibian eggs and larvae. Over the course of evolution, several species of salamanders and frogs exploited these fish-less water bodies. Today, these species exhibit “hard-wired” instincts and behaviors that are geared exclusively towards fish-free vernal habitats.
Amphibians that are dependent upon vernal pools are known as “obligate vernal pool breeders.” In New Jersey there are seven species – two frogs and five salamanders – that fit this category. Another 14 of New Jersey’s amphibians also use vernal pools for breeding, but unlike the ‘obligate’ species, these species can successfully reproduce in habitats that contain fish. These species are known as “facultative vernal pool breeders.”
Obligate and Facultative Vernal Pool Breeding Amphibians:
Obligate Vernal Pool Breeding Amphibians:
Eastern tiger salamander (Ambystoma t. tigrinum) Endangered
Marbled salamander (A. opacum) Special Concern
Spotted salamander (A. maculatum)
Jefferson salamander (A. jeffersonianum) Special Concern
Blue-spotted salamander (A. laterale) Endangered
Wood frog (Rana sylvatica)
Eastern spadefoot toad (Scaphiopus holbrookii)
Facultative Vernal Pool Breeding Amphibians:
Green frog (Rana clamitans melanota)
Bullfrog (R. catesbiana)
Pickerel frog (R. palustris)
Southern leopard frog (R. utricularia)
Carpenter frog (R.virgatipes) Special Concern
Northern cricket frog (Acris crepitans)
Northern spring peeper (Psuedacris crucifer)
New Jersey chorus frog (P. triseriata kalmii)
Upland chorus frog (P. triseriata ferarium)
Northern gray treefrog (Hyla versicolor)
Southern gray treefrog (H. chrysocelis) Endangered
Pine Barrens treefrog (H. andersonii) Threatened
Four-toed salamander (Hemidactylium scutatum)
Long-tailed salamander (Eurycea l. longicauda) Threatened
American toad (Bufo americanus)
Fowler’s Toad (B. fowlerii) Special Concern
In addition to amphibians, there are several reptiles that inhabit vernal pools on a seasonal basis, primarily to eat the eggs and larvae of amphibians:
Wood turtle (Glyptemys insculpta) Threatened
Spotted turtle (Clemmys guttata) Special Concern
Mud turtle (Kinosternon subrubrum)
Eastern painted turtle (Chrysemys picta picta)
Common snapping turtle (Chelydra serpentina serpentina)
Given the importance of these pools in preserving diversity, the 2001 NJ Endangered and Nongame Species Program’s established its Vernal Pool Project, which is a dedicated effort to map and survey vernal pools throughout the state. Vernal pools that provide documented habitat for certain amphibian and reptiles species (= certified) will be afforded regulatory protection through the new rule. Mountain Lakes has 9 vernal ponds that have been mapped under this project.
Locally, members of the Woodlands Commission and naturalist Rick Radis have identified upwards of 20 individual pools: at least five vernal pools are found in the Yorke Road woodlands; six are in Wilcox Park; two in Frederick Park; three in Tower Hill; a large complex is present immediately to the west of St. Catherine’s Church on Pocono Road; two are in woodlands in the vicinity of the municipal building; and others are scattered in small wooded tracts throughout the town.
The vernal ponds in the Yorke Road woodlands are home to the endangered blue-spotted salamander.
Other rare mole salamanders such as spotted, Jefferson’s and marbled; wood frogs; spring peepers and other tree frog species exist in these pools as well (see Fauna section of this report).