Salamanders and fish are important taxonomic groups in headwater streams, where they play the role of top predators and also prey.
Just as the presence of certain benthic macroinvertebrates is a measure of water and habitat quality, so, too, is salamander and fish presence and abundance. In our region, streams are home to at least — species of fish and several salamanders species including the two-lined salamander, northern red salamander, northern dusky salamander, and northern long-tailed salamander, a threatened species in New Jersey.
Raritan Headwaters staff and volunteers will continued to surveying salamander populations at our stream monitoring sites already being monitored for “benthic macroinvertebrates,” small creatures that live in river and stream beds. Raritan Headwaters has been using benthic macroinvertebrates living in streams as indicators of water quality since the 1990s.
Vernal pools are ephemeral, isolated wetlands without fish living in them. Many are woodland pools but they can also be found in more open habitats such as meadows. Due to the lack of predatory fish, they are breeding hotspots for a host of amphibians, including wood frogs, and spotted, Jefferson and marbled salamanders. They are also used by reptiles, birds, mammals and arthropods.
The first late winter-early spring rains harken the movement of spotted and Jefferson salamanders, wood frogs, toads and a variety of other amphibians from their upland resting places to their breeding wetlands known as vernal pools, where they will lay millions of eggs. These species often suffer high mortality on roads, which they often cross en masse on cold rainy nights as they return to the same pool each year. In some places, the roads are closed on those evenings or volunteers are ready to help amphibians across the road and document their numbers.
Mapping done by the New Jersey Department of Environmental Protection (NJDEP) indicates that there may be at least 461 vernal pools within the North and South Branch Raritan watershed. However, only 121 of them have been confirmed vernal pools based on a list of criteria. Because vernal pools are typically small, most are less than .25 acre, they miss the critical wetland protections afforded wetlands that are greater than or equal to 1 acre.
Raritan Headwaters will continue investigating each potential location – not once, but four times, as required by the NJDEP – to learn what conditions exist throughout the seasons. If vernal pools are found, they have water for at least two months of the year, and are documented as breeding sites for amphibians, they are eligible for special state protections.
To ensure protection of biodiversity in the upper Raritan River watershed, important wildlife habitats must stay connected.
For example, many salamanders and frogs spend the winter in upland habitats, but migrate to wetlands and vernal pools on lower ground to breed. If their path is blocked by roads, many can be killed or fail to reach their breeding places. In addition, poorly designed or structurally deteriorating culverts, bridges and dams can disrupt the connectivity of streams and prevent movement of fish and other aquatic organisms upstream and downstream.
Since 2018, Raritan Headwaters been participating in the North American Aquatic Connectivity Collaborative (NAACC) and Connecting Habitat Across New Jersey (CHANJ) to assess whether culverts, bridges and other crossings are interfering with movement of aquatic and terrestrial organisms and which are providing important road crossing tunnels for wildlife. The goal is to share these data with municipalities and other partners in order to ensure connections are maintained or restored. In 2021, RHA assessed 150 stream-road crossings in the Upper Raritan for terrestrial and aquatic connectivity on behalf of the NJ Fish and Wildlife, Endangered and Nongame Species Program. Read our August 2022 Final Report.