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New Jersey's Vernal Pools

by Jason Tesauro
Assistant Zoologist

Vernal pool in spring An estimated 3,000-5,000 vernal pools occur in New Jersey - natural or man-made depressions that hold water, but not fish, for at least two consecutive months out of the year. These pools provide habitat for many species of amphibians, insects, reptiles, plants and other wildlife.

The Division of Fish and Wildlife's Endangered and Nongame Species Program (ENSP) has documented less than 10% of the state's vernal pools, but now plans to take vernal pool mapping and surveying by storm…and needs your help! With only a few biologists to dedicate towards vernal pool fieldwork, the ENSP is desperate for volunteers to participate in vernal pool surveys. (Volunteers will become members of the Division's volunteer wing, the Wildlife Conservation Corps.)

Northern Cricket Frog In 2002, between February and June (the best time to survey for breeding amphibians) the ENSP will be making a concerted effort to document as many pools as possible. The ENSP will have a map of vernal pools that need to be surveyed for certification purposes, primarily in rural portions of the Coastal Plain, Skylands and Piedmont landscapes, areas where vernal pools appear to be most abundant.

Volunteers can select a survey area (i.e. specific pools or tracts of land containing complexes of pools) and take data on pool locations and species observed. The ENSP will hold vernal pool training seminars with both both lecture and a field components during March, 2002.

Why Survey Vernal Pools?

Vernal pool in spring The main objectives of the Vernal Pool Project are to map and inventory vernal pools statewideand determine the status, range and distribution of obligate (dependent upon) vernal pool amphibians. Currently, the ENSP has data on only 230 of these habitats. With the assistance of staff biologists, volunteers, and Rutgers University's cutting-edge remote sensing techniques, the ENSP is determined to map and inventory the majority of New Jersey's vernal pools over the next few years.

As vernal pools and their associated faunal (animal) communities are documented, the information will be integrated into the regulatory database of the Department of Environmental Protection, which for the first will be protecting vernal pools. The data will also become part of the Landscape Project's critical habitat mapping, which is intended to assist wise land use planning.

What is a vernal pool?

Vernal pools are confined 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. Vernal pools provide habitat to many species of amphibians, insects, reptiles, plants, and other wildlife. The absence of fish is the essence of these ecosystems. Spotted Salamander

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 "hardwired" instincts and behaviors that are geared exclusively towards fish-free aquatic habitats.

Species 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."

Vernal Pool Protection

Vernal pool in late spring New Jersey has recently adopted legislation to protect vernal pools. Although the NJ Freshwater Wetlands Protection Act has been in place since 1989, it has done little to protect vernal pools because wetlands smaller than 1 acre (most vernal pools in NJ are less than 0.25 acre) are exempt from the regulatory protection. Vernal pools can be filled, drained, or modified with a general permit. The new vernal pool (or 'vernal habitat,' as it is known in regulatory language) regulations protect vernal pools that are known meet the following certification criteria: For further information on New Jersey's vernal pool certification process go to:
For maps of vernal pools already certified go to:

How are Vernal Pools Protected?

The primary way in which DEP's Land Use Regulation Program (LURP) is implementing vernal pool protection is through cross-referencing land use permit applications with mapping of certified vernal pools. When a permit is applied for, LURP staff will review maps showing all locations of certified vernal pools. Blue-spotted Salamander

Projects proposed in vernal pools may need to be redesigned to avoid adversely impacting them, or the permit may potentially be denied. However, this protection can only be applied to vernal pools that have been certified. Thus vernal pool protection in New Jersey is highly dependent upon the generation of a comprehensive map of all the certified vernal pools in the state.

The other method in which DEP intends to protect vernal pools is through Landscape Mapping. This statewide digital mapping, available online since fall, 2001, contains critical habitat for all of the New Jersey's endangered, threatened, and special concern animals. The intended purpose of this mapping is to guide sensible land use planning at the state, county and municipal level. Once mapped and inventoried, vernal pools will be incorporated as a data layer into these critical habitat maps.

Materials and Publications

NJ Chorus Frog The ENSP is currently working on two publications, a vernal pool field guide and a pamphlet that outlines how vernal pools can be protected in New Jersey. Look for these early 2002.

For information on any the vernal pool species listed above log on to our online field guides at:

Obligate and Facultative Vernal Pool Breeding Amphibians

Obligate Vernal Pool Breeding Amphibians:
Eastern tiger salamander (Ambystoma t. tigrinum)
Marbled salamander (A. opacum)
Spotted salamander (A. maculatum)
Jefferson salamander (A. jeffersonianum)
Blue-spotted salamander (A. laterale)
Wood frog (Rana sylvatica)
Eastern spadefoot toad (Scaphiopus holbrookii)

Pine Barrens Tree Frog Facultative Vernal Pool Breeding Amphibians:
Green frog (Rana clamitans melanota)
Bullfrog (Rana catesbiana)
Pickerel frog (Rana palustris)
Southern leopard frog (Rana utricularia)
Carpenter frog (Rana virgatipes)
Northern spring peeper (Psuedacris crucifer)
Northern cricket frog (Acris crepitans)
New Jersey chorus frog (Pseudacris triseriata kalmii)
Upland chorus frog (Pseudacris triseriata ferarium)
Northern gray treefrog (Hyla versicolor)
Southern gray treefrog (Hyla chrysocelis)
Pine barrens treefrog (Hyla andersonii)
Four-toed salamander (Hemidactylium scutatum)
Long-tailed salamander (Eurycea l. longicauda)

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 (Clemmys insculpta)
Spotted turtle (Clemmys guttata)
Mud turtle (Kinosternon subrubrum)
Eastern painted turtle (Chrysemys p. picta)
Common snapping turtle (Chelydra s. serpentina)

Photo Credits:

Northern Cricket Frog by Blaine Rothauser
Spotted Salamander, Blue-spotted Salamander and NJ Chorus Frog by R. Zappalorti
Pine Barrens Treefrog by Breck Kent
Others by NJ DF&W, Endangered and Nongame Species Program
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