δD and δ18O evidence for inputs to groundwater at a wetland coastal boundary in the southern Great Lakes region of Canada

The stable isotope compositions (δ18O and δD) of water have been used to determine the relative contributions of different water sources to the groundwater in a barrier sand-bar that separates a coastal freshwater marsh from Lake Erie, Canada. An extensive groundwater study was initiated by Environment Canada at Point Pelee National Park after elevated nutrient concentrations were measured in the park’s marsh, located on a spit of land that …