Dietary mercury exposure and bioaccumulation in amphibian larvae inhabiting Carolina bay wetlands
J.M. Unrine*, C.H. Jagoe, A.C. Brinton, H.A. Brant, N.T. Garvin
Savannah River Ecology Laboratory, The University of Georgia, P.O.
Drawer E, Aiken, SC 29803, USA
Received
21 June 2004; accepted 5 November 2004
Tadpoles accumulate significant concentrations of mercury in isolated
wetlands.
Abstract
Inorganic mercury and methylmercury concentrations were measured both
in guts and remaining carcasses of southern leopard frog (Rana sphenocephala)
larvae from 10 Carolina bay wetlands in South Carolina, USA. Significant
variation among bays in methylmercury and inorganic mercury concentrations
existed both in guts and carcasses. There was a moderate negative correlation
between dissolved organic carbon concentration in bays and mean inorganic
mercury concentrations in guts. There was also a weak positive correlation
between pH in bays and mean methylmercury concentrations in carcasses.
The ratio of methylmercury to inorganic mercury decreased with increasing
total mercury concentration in guts and in larvae, but the rate of decrease
was highly variable among bays. Ratios of concentrations in carcasses
to concentrations in guts were inversely related to gut concentration.
Mercury concentrations in carcasses in some bays were within the range
of concentrations at which adverse effects have been observed in laboratory
studies of R. sphenocephala.
@ 2004 Elsevier Ltd. All rights reserved.
Keywords: Amphibian; Mercury; Speciation; Trophic transfer; Wetland
SREL Reprint #2819
Unrine, J. M., C. H. Jagoe, A. C. Brinton, H. A. Brant and N. T. Garvin. 2005. Dietary mercury exposure and bioaccumulation in amphibian larvae inhabiting Carolina bay wetlands. Environmental Pollution 135:245-253.
