Evaluation of Methods and Results in the Braddock Bay Wetland Restoration Project

Abstract

Prior to restoration, Braddock Bay was an open embayment wetland on the southern coast of Lake Ontario, and it is part of the Rochester Embayment Great Lakes Area of Concern (AoC). Braddock Bay was partially protected by two spits that are remnants of the protective barrier beach that has slowly been eroded over time. Without the barrier to protect the shoreline within the bay, the coastal wetland was severely impacted by wave action from Lake Ontario, leading to loss of 43 hectares of wetland. The erosion of the barrier was facilitated by water-level regulations implemented in the late 1950s. A further consequence of water-level regulation was the loss of diversity, as the lack of periodic low water levels resulted in a cattail monoculture and the loss of sedge/grass meadow habitat. Braddock Bay is being restored by the United States Army Corps of Engineers. The plan called for the following: restoration of a portion of existing cattail-dominated wetland by cutting cattails in August (when storage carbohydrates in rhizomes are minimized) and herbicide treatment of new stems; channeling and potholing to improve wildlife access to the wetland; the re-creation of the historical barrier beach using rubble-mound and sand; and the creation of spoil mounds along the channels and potholes to increase the elevation in these areas and discourage the growth of cattail while supporting the growth of sedge/grass meadow species. Two years of data collection were performed following construction activities in 2016. Preliminary surveys showed an increase in an invasive species of concern (purple loosestrife) from year 1 to year 2 across the restoration site. A decrease in cattail across the years was observed in the cattail treatment areas, along with a slight decrease of Typha found in the sedge/grass meadow and spoil mound habitats. Based on this monitoring, construction standards set for the restoration must be met, and adaptive management must occur throughout the project timeline for restorations to succeed. Site-level weighted mean C metrics are recommended for future floristic analyses based on an observed species richness influence on FQAI.