PHOSPHORUS CYCLING IN THE ELLISON PARK WETLAND, IRONDEQUOIT BAY, LAKE ONTARIO, NY

Wetlands are characterized as important ecosystems that act as filters and sinks for nutrients. Some research has found that this blanket characterization of wetlands may not be adequate for some nutrients, such as phosphorus. The filtering efficiency of a wetland depends on multiple factors, such as: wetland type, soil type, vegetation, residency time, flow rate, and sedimentation.

The Ellison Park wetland complex lies at the head of Irondequoit Bay, a large embayment on the south shore of Lake Ontario near Rochester, NY. It receives water from the Irondequoit Creek watershed, which drains an area of 460 km² of mixed land use. This is a mature, marsh wetland with some locations encompassing riparian wetland characteristics. Researchers have found mature wetlands to not be effective in retaining P below 1 mg/L (Alder et al. 1996). Previous research has found that Ellison Park may be a source of orthophosphate to Irondequoit Bay (Coon 2004). In this study, a segment analysis sampling scheme and a simple aggregated watershed model (Mitsch and Wang 2000) was used to explore phosphorus pathways through this coastal wetland system. Results to date for soluble reactive phosphorus (SRP) and total phosphorus (TP) show values in stream and wetland samples ranging from 5.01 to 57.82 mg/L for SRP and 31.72 to 284.67 mg/L for TP for non-event samples. Storm event samples are typically at higher concentrations ranging from 2.33 to 93.00 mg/L for SRP and 17.27 to 325.92 mg/L for TP. For SRP, storm events and non-events are significantly different, but this is not seen for TP. Concentrations for Irondequoit Bay epilimnion water are similar to stream water for SRP during non-events and TP during storm events. During storm events, concentrations of SRP within the stream and wetland are elevated above the bay, but TP values are lower. Results suggest that during storm events, the Ellison Park wetland complex may be acting as a source, especially for SRP. Modeling of individual events and storm and non-event averages, coupled with sediment P concentrations is underway in an attempt to elucidate the cycling of P within the wetland complex.