Spatial distribution of acid-volatile sulfur in the sediments of Canadohta Lake, PA

Abstract

Lake sediments are an important source of dissolvedsubstances and can be the site of processes importantto the biogeochemical cycling of nutrients and metals. Most studies which examine these processes, however,are based on the analysis of a single or a very fewsediment cores taken at or near the deepest area ofthe lake. The implicit assumption is that lakesediments are spatially homogeneous and thatextrapolations from such limited samples arerepresentative of the lake sediments throughout thelake basin. We examined this assumption with respectto concentrations of acid volatile sulfides (S2-vol) – sulfur species which have beenimplicated in eutrophication, acid-neutralization, andheavy-metal toxicity. S2-volconcentrations measured in the surficial sediments ofCanadohta Lake, PA, a lake of very simple morphometry,ranged from 0.07 to 30.32 μg g-1 sediment dryweight. Concentrations were directly correlated withdepth and inversely correlated with organic matter. These results suggest that results extrapolated froma few deep-water cores can lead to a seriousoverestimation of S2-vol in the lakesediments.