Liz Berg's Graduate Exit Seminar

Liz Berg will present The Effect of Hydrological Restoration on Nutrient Concentrations, Macroinvertebrate Communities, and Amphibian Populations in Lake Erie Coastal Wetlands Thursday, December 13th at 10:30AM in Heffner Building 128.

Abstract:

Historically, coastal wetlands along the western Lake Erie basin supported important ecosystem functions including water quality improvement and biodiversity support. Most remaining coastal wetlands have been diked, severing the hydrologic connection to Lake Erie and its tributaries and acting as barriers to the exchange of water, nutrients, and biota. Concern over harmful algal blooms has led to large-scale coastal wetland restoration initiatives in the western Lake Erie basin. In particular, stakeholders have collaborated to hydrologically reconnect approximately 2,387 acres of protected, diked wetlands in Ottawa National Wildlife Refuge (ONWR). Restoring wetland connectivity has the potential to reduce inputs from the Maumee Area of Concern and reduce amphibian habitat fragmentation. Additionally, wetland restoration is expected to improve macroinvertebrate habitat and food resources in the long-term. However, hydrologic connection to Lake Erie and an impaired watershed may expose biota to new stressors such as nutrient enrichment and invasion of non-native species. In this study, I examined whether hydrologic wetland restoration of coastal wetlands in the western Lake Erie basin had an effect on nutrient concentrations, macroinvertebrate communities, and amphibian populations. Specifically, I compared nutrient concentrations, macroinvertebrate diversity and composition, and amphibian abundance and biomass in 5 restored and 7 diked coastal wetlands. If the reconnection of diked wetlands increased nutrient concentrations, I predicted that biota would experience direct and indirect effects of nutrient enrichment and begin to reflect environmental degradation. Nutrient concentrations varied in restored and diked wetlands, but not always as predicted. Macroinvertebrate communities reflected general properties of ONWR and varied with nutrient concentrations irrespective of the restoration. Amphibian populations were robust to changes in nutrient concentrations and resources. It is likely that large-scale environmental pressures persist and that hydrologic reconnection did not represent the primary limiting factor of macroinvertebrate communities and amphibian populations. Accelerated efforts to protect and restore Lake Erie coastal wetlands are attracting national investment (e.g. Great Lakes Restoration Initiative 2020) as the frequency and intensity of HABs increases. Therefore, it is increasingly important to understand what implications large-scale restoration initiatives have for biodiversity.