The Neuse River waterdog is one of the rarest salamanders in the Southeastern US. This permanently aquatic salamander received federal protection as threatened on June 9, 2021. As a narrow endemic, it is only found in the Neuse and Tar-Pamlico River Basins of North Carolina (NC). It lives in medium to large streams and rivers in the Piedmont and Coastal Plains.
The Service and state wildlife agencies are working with numerous partners to conserve the Neuse River waterdog and restore its habitat while meeting the socioeconomic, political and cultural needs of current and future generations. Land trusts are targeting key parcels for acquisition. Federal, state, and university biologists are surveying and monitoring species occurrences, and recently there has been increased interest in efforts to consider captive propagation and species population restoration via augmentation, expansion, and reintroduction efforts.
Habitat degradation is the primary threat. It affects water quality, water quantity, instream habitat suitability, and habitat connectivity. The remaining populations are small, isolated, with a contracted range that makes them vulnerable to catastrophic and natural events.?
The Neuse River waterdog is extremely susceptible to the effects of siltation, or the deposit of sediments in freshwater. The major threats to this species arise from water development projects such as the construction of impoundments and stream channelization. Pollution from industrial and urban development can also cause loss of habitat by lowering dissolved oxygen levels and increasing suspended solids and sediments in streams.
Other nonpoint sources of pollution carried into the streams by water, or runoff also affects the Neuse River waterdog. Natural and human-made substances like animal waste, fertilizers, pesticides, herbicides, and chemicals associated with coal mining can all cause changes in water chemistry that severely impact aquatic species. Increased levels of nitrogen and phosphorus, excessive algal growth, instream oxygen deficiencies, increased acidity, and conductivity can all have adverse effects on the health of river dwelling species.
Actions and partnerships underway
The USFWS and the North Carolina Wildlife Resources Commission (NCWRC) funded a 5-year research project. As of May 2021, the Service awarded $110,000 to North Carolina State University to examine the relationship between environmental stressors and the distribution, drivers of reproduction and population viability of Neuse River waterdogs. Researchers will project how future land use may affect the species’ ability to persist in its current range and make recommendations for surveys to improve detection.
Recovery plan under development
In November 2021, the Service adopted a Recovery Outline for the Neuse River Waterdog. The document offers a preliminary road to recovery for the Neuse River Waterdog until a recovery plan for the species is approved. The recovery plan will include objective and measurable criteria that, when met, will ensure the conservation of the waterdog.
Facilitating habitat restoration and releasing waterdogs in private lands
The USFWS and NCWRC have drafted a programmatic Safe Harbor Agreement for 21 aquatic species that will support species restoration efforts, including population augmentation and reintroduction of the Neuse River Waterdog into historically occupied or other suitable habitats. The draft agreement is currently under review by staff at both agencies.
Avoiding, minimizing and mitigating impacts from transportation projects
The USFWS and NC Department of Transportation have entered into a programmatic consultation agreement to minimize and mitigate impacts from bridge and culvert construction and maintenance activities. We seek to ensure projects are conducted with appropriate methods for protecting instream habitat, and support recovery actions for the Neuse River Waterdog through fees.
Conservation land trusts are targeting parcels for acquisition in key watersheds occupied by the Neuse River Waterdog.
Facilitating conservation at commercial timber thinning or harvest
The USFWS and the NC Forest Service have partnered to implement Foresters for Healthy Waters, a program that offers supplemental conservation assistance for landowners who want to implement enhanced aquatic habitat protection for rare and at-risk species. The two-year pilot program is underway in seven counties within the Neuse River Waterdog’s range, and it may be continued and expanded if successful.
The USFWS included exceptions to the prohibition of incidental take in the final listing rule, in accordance with section 4(d) of the Endangered Species Act, for species restoration efforts, channel restoration and bank stabilization projects, and certain forest management activities that are expected to offer net conservation benefits.
The USFWS designated critical habitat at 779 river miles that fall within 18 units in Craven, Durham, Edgecombe, Franklin, Granville, Greene, Halifax, Johnston, Jones, Lenoir, Nash, Orange, Person, Pitt, Wake, Warren, Wayne, and Wilson Counties, North Carolina. The designation extends Endangered Species Act protections to the critical habitats.
The North Carolina Department of Environmental Quality has special nutrient management plans for the Tar-Pamlico River Basin and the Neuse River Basin to help reduce nutrients that cause excessive growth of microscopic or macroscopic vegetation and lead to extremely low levels of dissolved oxygen in the water.
Longevity of Neuse River Waterdog is unknown. However, its close relative, Necturus maculosus may live for over 30 years.
The sexes (genders) are similar in appearance, and adults can be distinguished only by the shape andof the cloacal area. Waterdogs breed annually, mating in the fall/winter, seasons and females spawn in the spring. Clutch sizes vary from an average of 25 to 90 eggs. Both parents guard the nest.
Post-hatchling larvae have a broad, light tan, dorsal stripe from the snout to the tail, and along the dorsal region are small, poorly defined, dark spots. The underside of the larvae is white or has a faint network of lines.
The Neuse River Waterdog typically reaches an adult length of 6 – 9 inches (~ 15 – 23 cm) and can be identified by its reddish-brown skin with black spots, a brownish-grey spotted underside, and external, filamentous, dark red gills. They eat aquatic and terrestrial invertebrates (e.g., insect larvae, small crustaceans, spiders, snails, and worms) and some vertebrates (e.g., small fishes). Neuse River Waterdogs breed once per year in late autumn/winter. Females then deposit approximately 25 – 50 fertilized eggs in spring, typically under large rocks over gravel or hard clay, where either parent can guard the rudimentary nest (NCWRC 2020). In coastal rivers where rocky habitat is limited, they nest under available cover, such as logs or holes in banks. Juveniles and adults also rely on silt-free leaf litter as foraging habitat. Neuse River Waterdogs tend to grow slowly, and reproduction is delayed until a minimum body size is reached (typically around age 5 or 6).
The Neuse River waterdog specific habitat characteristics include low to moderate gradient streams and low current velocity. It is a fully aquatic salamander, never leaving the water. It lacks lungs, getting oxygen from the water via external gills and needs clean, flowing water with high dissolved oxygen concentrations. The species dwells in streams wider than 15 meters but has been found in smaller creeks.
The species thrives in cold water and is much more active in colder seasons and when water is near freezing. Researchers have documented activity decreasing after the water temperature rises above 18ºC. waterdogs spend about 85% of the time under large granite rocks or in burrows. In early spring they move into leaf beds over mud banks on the low-energy sides of riffles and where leaves were intact or only slightly decomposed and many small critters are in the leaf litter. Photo: https://flic.kr/p/iD5LwL
A natural body of running water.
Neuse River waterdogs are sight and scent feeders, with prey consisting of aquatic arthropods (primarily ostracods and copepods), hellgrammites, mayflies, caddisflies, crayfish, beetles, caterpillars, snails, spiders, earthworms, centipedes, millipedes, slugs) and some small fish like darters and pirate perch. Prey is ingested whole, and larger items are sometimes regurgitated and then re-swallowed.
The Neuse River waterdog (Necturus lewisi) is a permanently aquatic salamander. It can grow up to 11 inches long. It has a reddish- brown body with an irregular pattern of large blue or black spots. The waterdog has a laterally compressed tail the same coloration as the body; however, the belly is typically a dull brown or gray color with spots similar to those seen elsewhere on the body. Adult Neuse River Waterdogs have elongated heads with squared-off noses, cylindrical trunks, and tails that are laterally compressed and ridged.
Three dark-red, bushy gills project from either side of the head and a dark line runs through the eye. The skin is smooth, slimy and a light rusty brown color, with the belly being a paler brown or grayish. There are dark brown or blackish spots throughout the surface that are smaller on the underside. The limbs are rather small, and the front and hind feet have four toes each (unlike most salamanders, which have five toes on each back foot).
Its appearance is significantly different in earlier life stages, as hatchlings and larvae. Hatchlings are light brown in color with dark lines from each nostril through the eye to the gills, with a white patch behind the eye and above the line. Their heads are round when compared to the square, elongated heads of the adults. Hatchlings have spots with concentrations highest on the tail, making the tail darker than the head and trunk. Their forelimbs have three complete toes, and a bud that will later develop into the inner fourth toe. The hindlimbs are not yet developed.
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