Freshwater mussels, dragonflies and damselflies, and stream-associated herptiles are excellent indicators of water quality. Declines within populations of these groups may serve as early warning indicators of deteriorating water quality. Freshwater mussels, which spend their entire lives in the aquatic environment, have a low tolerance for water-borne pollutants and are especially useful as water quality indicators and overall stream health. The Nature Conservancy estimates that 55% of North America's mussel species are extinct or imperiled compared to only 7% of the continent's mammal and bird species. In addition, a number of the endangered species are functionally extinct, with the individuals of a species surviving but not reproducing. Since some mussel species can live in excess of a century, population declines may not be immediately apparent. Freshwater mussel extinctions and declines can be attributed to habitat degradation, construction of dams, and expansion of exotic species. There are 12 native freshwater mussel species in the state, nine of which are listed as Endangered, Threatened or Special Concern.

Stream dragonflies and damselflies have been much more severely impacted by human activities than pond species. Approximately 15% of North American dragonfly species are at risk of extinction in the foreseeable future. Stream-associated Odonata are threatened by water quality degradation due to fertilizer and pesticide runoff, sewage and organic wastes, and siltation due to erosion. In addition, the construction of dams often results in the replacement of rare stream dragonflies with more common pond species. There are 172 Odonata species found in New Jersey, with 43 considered rare and tracked by the NJ Natural Heritage Program.

Reptiles and amphibians are similarly threatened by degraded water quality conditions. In recent years, herptile populations have been noticeably decreasing. The most influential factors in their decline has been development within critical habitat, habitat fragmentation, and decreased environmental quality. Amphibian declines have been linked to the presence of fertilizers in aquatic habitats. Other pollutants thought to have negative impacts on amphibians include pesticides and heavy metals. Seventy-two herptile species inhabit the state, 17 of which are listed as Endangered or Threatened.

Endangered and Nongame Species Program biologists, through funding from the Division of Science, Research and Technology (DSRT), searched the state's waterways for freshwater mussels, dragonflies and damselflies, and stream-associated reptiles and amphibians during 2000-2002. Survey sites were selected based upon the following criteria:

1) wadeable Ambient Biomonitoring Network (AMNET) location
2) proximate to occurrences of Endangered, Threatened or rare freshwater mussel species and/or suitable habitats
3) proximate to occurrences of rare Odonata and/or suitable habitats
4) Pinelands habitat suitable to support a diverse Odonata fauna.

1) visual observations during mussel and Odonata surveys
2) moving rocks, logs and stream debris
3) listening for vocalizations.

During the first two years of the project, we documented eight of the state's 12 freshwater mussel species. In 2000, we conducted qualitative surveys and habitat assessments at 27 AMNET locations, encompassing 11 counties. The federally and state endangered Dwarf Wedgemussel was found in the Pequest River, thereby documenting the first live specimen of the species from the river. In addition, we identified state listed and rare freshwater mussel species, including the Triangle Floater, Eastern Lampmussel, Eastern Pondmussel and Creeper, at seven sites. The Musconetcong River, Long Branch, Hayne's Creek, and Raccoon Creek had the highest diversities of Odonata.

We located several rare Odonata species, including the Umber Shadowdragon and and four shells were documented in the Pequest River, along with live Brook Floaters, a state Endangered species, in the Lamington River. Also, we documented Triangle Floaters in six streams. Sites with the highest diversities of mussels included the Paulins Kill, Scotland Run, and Pequest and Lamington rivers. The most productive area for Odonata was Oyster Creek in Waretown, yielding 29 species in a single day. Rare state-tracked Odonata species including the Robust Baskettail, Umber Shadowdragon, Zebra Clubtail, Stygian Shadowdragon and Brook Snaketail were found.

In 2002, we conducted qualitative surveys and habitat assessments at 30 AMNET and close alternative locations encompassing 10 counties. We surveyed 67 habitat segments composed of 43 runs, six riffles and ten pools. We found a live Brook Floater in the Stony Brook; this species was recently listed as state Endangered and is only reported live from a few New Jersey locations. In addition, we found rare mussel species such as the Triangle Floater and Creeper. The Paulins Kill and Stony Brook had the highest diversities of freshwater mussels, with five species each. An analysis of combined year findings suggests that freshwater mussels prefer an optimum range of habitat score. In addition, our data show that rising total vegetative protection scores are associated with greater maximum freshwater mussel abundance. Broader relationships may exist between freshwater mussel abundance/diversity and specific habitat parameters such as flow status, epifaunal cover and total riparian width.

Also in 2002, we located Odonata at 27 out of 28 sites surveyed, with species identified as adults, tenerals, larvae and/or exuviae. Of the 76 Odonata species we encountered during the field season, 24 were damselflies and 52 were dragonflies. We found rare species such as the River Jewelwing, Sparkling Jewelwing, Scarlet Bluet, Spine-crowned Clubtail, Banner Clubtail, Main Snaketail, Russet-tipped Clubtail, Arrow Spiketail and Allegheny River Cruiser. Odonata diversity was highest at Burr's Mill Brook and Lubber's Run, with 21 and 17 species respectively. Our surveys during 2002 resulted in the discovery of seven county records, bringing the total number of county records achieved during the project to 15. There exists an obvious relationship between rare Odonata species presence and pooled habitat scores. Also, there appears to be a strong relationship between total number of Odonata species and the number of Heritage-tracked species. According to our data, two tracked species should be found when the total number of species equals 10. In addition, expect six total species to include one tracked species.

Future efforts will include quantitative surveys in areas where endangered freshwater mussel species were encountered, along with season-wide monitoring of sites with rare and soon-to-be listed Odonata. By using data on fish occurrences collected through the IBAA, we will target areas that contain specific host fishes for endangered mussels, thereby increasing the likelihood of locating rare species while further overlapping survey areas. The relationship between EPA Habitat Assessment scores and the presence of rare freshwater mussel and Odonata species will be explored further. We will also study the effects of electroshocking on freshwater mussels, larval Odonata and herptiles by conducting time species searches at a test site before and after BFF electroshocking activities.

Results from the ENSP and the BFF field surveys will vastly improve our knowledge of New Jersey's water quality indicators. Combined with data from BIS, these survey efforts will complete the first ever statewide review of aquatic resources. Location data and habitat information for Endangered, Threatened, and rare species will be supplied to the NJ Division of Parks and Forestry's Natural Heritage Program for entry into the Biological Conservation Database (BCD). Also, results from IBAA surveys will be incorporated into the ENSP's recently initiated Riparian Landscape Project and our ongoing Herptile Atlas Project. Finally, we will use endangered and threatened species information as a possible basis for recommending stream classification upgrades in critical, high quality habitats.

Dwarf Wedgemussel - August 2003 Species of the Month

Sources

Bauer, G. 1992. Variation in the life span and size of the freshwater pearl mussel. Journal of Animal Ecology 61:425-436.

Bogan, A.E. 1993. Freshwater bivalve extinctions (Mollusca: Unionoida): a search for causes. Amer. Zool. 33:599-609.

Dunkle, S.W. 1990. Damselflies of Florida, Bermuda and the Bahamas. Scientific Publishers, Gainsville, Florida. 148 pp.

Dunkle, S.W. 2000. Dragonflies Through Binoculars: A Field Guide to Dragonflies of North America. Oxford University Press, Inc., New York, New York. 266 pp.

Helfrich, L.A., Neves, R.J., Weigmann, D.L. and R.M. Speenburgh. 1993. Help Save America's Pearly Mussels. Virginia Polytechnic Institute and State University, Publication 420-014. Blacksburg, Virginia. 16 pp.

Marco, A., Quilchano, C. and A.R. Blaustein. 1999. Sensitivity to nitrate and nitrite in pond-breeding amphibians from the Pacific northwest. Environmental Toxicology and Chemistry Vol. 18(12):2836-2839.

Master, L. 1990. The imperiled status of North American aquatic animals. Biodiversity Network News 3:1-2, 7-8.

U.S. Fish and Wildlife Service. 2000. Amphibian Declines and Deformities. Environmental Contaminants Program Web Site.