SPATIAL PATTERNS IN SURFACE SEDIMENTS OF SKANEATELES LAKE (NEW YORK) AND THEIR RELATIONSHIP TO HARMFUL ALGAL BLOOMS

Exploring the physical and chemical variability at the sediment-water interface of Skaneateles Lake is a key to understanding the mechanisms that drive harmful algal blooms (HABs). Skaneateles in an oligotrophic, dimictic lake that has served as the primary unfiltered water source for the city of Syracuse since 1894. Since 2017, the lake has been affected by HABs of Microcystiswhich pose a threat to the aquatic ecosystem as well as human health. Skaneateles lake provides a unique environment for studying the mechanisms that drive blooms due to the relatively low nutrient concentrations in the water column (total phosphorus ~ 5 µg/L). This research utilizes near-shore shallow sediment samples collected from 130 sites from 17 transects around the shelf region of the lake during the summer of 2019, in order to understand the magnitude of internal release of phosphorus and infer sediment-water interactions that could affect the occurrence of HABs. Initial patterns in sediment phosphorus concentration display increasing concentration with increasing water depth. Additionally, the positive association of iron with phosphorus in the sediment and pore water suggests an important role of iron and redox processes in the release of phosphorus to the water column.