A retrospective analysis of suspended solids deposition in Onondaga Lake, NY: Composition, temporal patterns and drivers.

摘要

Long-term and seasonal temporal patterns in the deposition of total (TSS), fixed (FSS), and volatile suspended solids (VSS) are documented for Onondaga Lake, NY from 1980-2008 using sediment traps. Downward fluxes of TSS (DFTSS), FSS, and VSS decreased ∼40% following reductions in ionic loading in 1986. DFTSS decreased 47% from 2007-2008, driven by lower CaCO3 deposition as DFCaCO3 accounted for 69% of DFTSS. Sediment accumulation rates were estimated at 0.8 cm/yr (1980-1986) to 0.2 cm/yr (2008). DFVSS decreased 56% from 1989-2008. Decreased phosphorus loading from a municipal wastewater treatment facility explained 67% of the interannual variations in DFVSS. DFVSS was generally correlated with chlorophyll in the epilimnion. Seasonal minima of DFVSS and DFFSS occurred during clear water phases, associated with Daphnia grazing. Changes in primary production and lake chemistry could have significant effects on the burial of contaminants and microbial metabolism in the sediments.;Key words: deposition, Onondaga Lake, phosphorus loading, sediment traps, suspended solids