AUTHORS: Rowan Faust, Lake Superior State University; Jonathan Doubek, Lake Superior State University
ABSTRACT: Interdunal wetland ponds are found at several locations along the shoreline of the Great Lakes, between the slacks of the foredune (dune closest to the lake) and subsequent dunes behind. These ponds are subject to water fluctuations from the Great Lakes via ground- and surface water, and are important “connecting” ecosystems for certain species, such as aquatic invertebrates, between the Great Lakes and smaller inland systems. However, very little research exists that characterizes the density and community composition of aquatic invertebrates in these systems, and how such metrics may vary across ponds of different environmental characteristics and sizes. To investigate this knowledge gap, six interdunal ponds, spanning a vegetation density, at Ludington State Park (west in Michigan’s Lower Peninsula) were sampled biweekly over the Summer of 2024 to characterize the aquatic invertebrate community. Aquatic invertebrates were collected using horizontal plankton tows, and a vegetation density index was calculated for each pond. Water temperature was recorded, and water samples were collected for later laboratory processing of water chemistry variables such as hardness, total phosphorus, and chloride concentration. Preliminary observations thus far indicate that a wide range of zooplankton and macroinvertebrate density and taxa richness exists across the ponds. Common taxa observed are Polyphemus, Daphnia, Ceriodaphnia, and calanoid copepods. Once all samples are processed this Fall, we will test if interdunal pond environmental characteristics and size affect aquatic invertebrate density, taxa richness, and community composition. Results will increase our understanding of these interdunal ponds, which are important to study as connector ecosystems between deeper and larger systems during an era of global change.
