Effects of spray-irrigated wastewater effluent on temporary pond-breeding amphibians.
Comparison was made of abiotic conditions, amphibian reproductive outputs, and the survival of embryonic and larval amphibians in wastewater effluent-irrigated and natural temporary ponds in an area in Centre County, Pennsylvania that has been spray-irrigated with secondarily treated, chlorinated wastewater effluent from The Pennsylvania State University for approximately 14 years. Three species of temporary pond-breeding amphibians were studied: wood frogs (Rana sylvatica LeConte), Jefferson salamanders (Ambystoma jeffersonianum Green), and spotted salamanders (A. maculatum Gravenhorst). Comparisons of physico-chemical parameters in 10 wastewater-irrigated and 10 natural temporary ponds over 19 weeks in 1997 indicated that wastewater -irrigated ponds had significantly higher median conductance, pH, ¿Na, ¿K, ¿Ca, ¿Mg, and ¿N-NO(3) and lower ¿dissolved oxygen. Many of the wastewater-irrigated ponds supported large mats of duckweed (Lemna spp.) that completely blanketed the pond's surface by mid-May. There were significantly fewer egg masses of all three species in wastewater-irrigated ponds than in natural ponds in both 1997 and 1998. In situ egg hatching success and larval survival (over a 6-day period) of all species was lower in wastewater-irrigated ponds than in natural ponds. Cumulatively, these studies suggest that wastewater effluent irrigation may impact amphibian populations by reducing the survival of amphibian eggs and larvae.
Laposata
M M
MM
Department of Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. mlaposat@kennesaw.edu
Dunson
W A
WA
D000557:Ambystoma / Q000502:physiology; D000818:Animals; D005618:Fresh Water; D007814:Larva / Q000187:drug effects; D011898:Ranidae / Q000502:physiology; D012722:Sewage; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D012722:Sewage; D014874:Water Pollutants, Chemical