Phosphorus Cycling in the Ellison Park Wetland at the Mouth of Irondequoit Creek, Rochester, NY: A Case Study Evaluating the Movement of Phosphorus as it Transits a Coastal Wetland of Lake Ontario

Abstract

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 391 km2 of mixed land use. This is a mature, marsh wetland with some locations encompassing riparian wetland characteristics. This project was developed to answer three objectives: what role hydrology plays in phosphorus (P) removal efficiency of the Ellison Park Wetland complex; what role sediments play in the retention or release of P; and the possibility of predicting P discharge from the Ellison Park Wetland into Irondequoit Bay. The results for soluble reactive phosphorus (SRP) and total phosphorus (TP) show values in stream and wetland water samples during baseflow event periods ranging from 5.01 to 10.87 µg L-1 for SRP and 22.73 to 88.67 µg L-1 for TP. Stormflow event water samples are typically at higher concentrations ranging from 6.24 to 9.300 µg L-1 for SRP and 46.65 to 428.33 µg L-1 for TP. The SRP and TP values give evidence that hydrologic event type plays a significant role in the quantity of P in Irondequoit Creek and its removal efficiency by Ellison Park. In addition, data suggests the direction of P flux in Ellison Park moves from the wetland sediments to the depleted water column; a result of historical nutrient loading. Modeling of TP data produced prediction errors of less than 5%, suggesting that Ellison Park tends to react in a predictable manner when regarding TP data in relation to hydrologic event type.