Effects of Treated Wastewater Effluent Irrigation on Terrestrial Salamanders

Abstract

Since 1983, State Game Lands 176 in Centre Co.,Pennsylvania, U.S.A., has been spray irrigated withtreated wastewater effluent as an alternative to thedirect discharge of treated effluent into surfacewaters. Although the effects of wastewater irrigationon birds and mammals had been studied, its effects onamphibians were unknown. We examined the physiological and behavioral responses of juvenile Jefferson salamanders (Ambystoma jeffersonianum Green) to effluent-irrigated soils and wastewater effluent in the field and laboratory to assess the effects of wastewater irrigation on the terrestrial phase of this species. Salamanders confined to irrigated soils for 35 d showed no difference in six physiological parameters (growth, body water concentration, and body sodium, potassium, calcium, and magnesium levels) compared to those enclosed on unirrigated soils. Salamanders on wastewater effluentsoaked substrates for the same duration in thelaboratory had higher body sodium concentration thanthose on deionized water soaked substrates, likely dueto elevated sodium levels in wastewater effluent.Salamanders demonstrated no `preference' for irrigatedor unirrigated soils over three days when allowed achoice between the two substrates in behavioral tests. These results suggest wastewater effluent irrigationis not acutely toxic to terrestrial A.jeffersonianum under natural conditions. Long-termadverse effects wastewater irrigation on terrestrialJefferson salamanders are still possible, andexaminations of salamander growth and survival overlonger durations are needed to assess the holisticimpacts of wastewater spraying on this species.