Modeling the contributions of birds and beach sand to FIB levels at a Great Lakes beach

Session: Poster session

Ammar Safaie, Michigan State University, [email protected]
Tuan Nguyen, Michigan State University, [email protected]
Chelsea Weiskerger, Michigan State University, [email protected]
Meredith Nevers, U.S. Geological Survey - Great Lakes Science Center, [email protected]
Mantha Phanikumar, Michigan State University, [email protected]

Abstract

The Jeorse Park beaches in Southern Lake Michigan have been identified as among the Nation’s most polluted beaches. To understand the relative influence of various sources contributing to pollution at the beaches, we developed a model of E. coli fate and transport. The model included contributions from nearby rivers, resuspension of contaminated sediments, beach sand along the shoreline, and shorebirds as well as processes such as wave-current interactions, sediment transport and sediment – bacteria interactions. The numerical models were tested against high-resolution field data, collected during summer of 2016 including E. coli concentrations in water, sand and sediment, total suspended sediment concentrations, and the number of gulls on the beach. Results indicate that sediment resuspension in the nearshore region and contributions from foreshore sand should be included to correctly model the observed E. coli data. The effect of tributaries draining into the lake was found to be negligible; therefore, birds are the major reason for the elevated E. coli levels at Jeorse Park beaches contributing either directly through water or indirectly from sand or resuspension of bottom sediment. Therefore, no additional sources beyond bird inputs are needed to explain the observed variability in E. coli concentrations at Jeorse Park.

1. Keyword
Lake Michigan

2. Keyword
water quality

3. Keyword
coastal processes

4. Additional Keyword
E. coli

5. Additional Keyword
beach sand

6. Additional Keyword
modeling