Applications of Tri-National Project Data: Comparing Tri-National Data for Soils with Data for Stream Waters and Sediments in the Maritimes, Canada

The geochemical analysis of stream sediment and water within the North American Soil Geochemical Landscape Project was initiated to fulfill two main objectives: 1) generate systematic baseline geochemical data for drainage basins across Canada and 2) provide data to facilitate the study of the relationship between the geochemistry of the soils and that of stream sediment and stream water within the same drainage basin.

The developmental phase of the Drainage Basin Geochemistry Project was conducted throughout New Brunswick during the fall of 2007. A GSC field crew visited 30 sites where stream sediment and a stream water samples were collected for lab analysis and also multiple field variables were measured in-situ. The stream site locations were selected within the same drainage basin and downstream from the previously sampled NASGLP soil sample sites. The drainage sites were selected within drainage basins with an areal extent of <100 km2, generally first or small second order streams.

Water variables measured in-situ included the following: pH, conductivity, temperature, dissolved oxygen, colour, turbidity and total discharge. Laboratory analyses undertaken on water samples were as follows: ICP-MS for trace elements, ICP-ES for major elements, ion chromatography for anions, alkalinity, dissolved organics and mercury. Stream sediment samples are analyzed by ICP-MS and INAA for more than 50 variables.

Preliminary examination of the stream water data for New Brunswick (n=30) indicate that concentrations of Hg (CV-AFS method) range from <0.5 ppt to 7.6 ppt, with a median of 2.4 ppt. Some of the samples with elevated Hg levels were collected in peatland areas in northeastern New Brunswick.