You are here:
Variability in physical and biological exchange among coastal wetlands and their adjacent Great Lakes
Citation:
Trebitz, A., M. Sierszen, J. Hoffman, AND A. Cotter. Variability in physical and biological exchange among coastal wetlands and their adjacent Great Lakes. Freshwater Science, Detroit, MI, May 20 - 24, 2018.
Impact/Purpose:
Among the important ecosystem services that coastal wetlands provide are fishery production support (feeding and sheltering species that provide recreational or commercial fishing) and water quality improvement (intercepting and processing watershed-derived nutrients and sediments before they enter the adjacent lake). This presentation examines the variability among wetlands in fish nutritional support and water quality processing and relates them to potential predictor variables related to hydrology, geomorphology, and landscape setting. To do so, we employ tools such as geochemical tracers and stable-isotope mixing models. Data sets used for the work derive both from recent research under SHC and from older research efforts under the former Water Quality RAP. Our results highlight the considerable complexity and diversity of coastal processes in the Great lakes and the challenge of generalizing the nature and extent of ecosystem services provided.
Description:
Hydrology is a major governor of physically-driven exchange among coastal wetlands and the adjacent Great Lake, whereas fish movement is a major governor of biologically-driven exchange. We use data describing coastal wetland morphology, hydrology, water quality, and fish tissue stable isotopes to examine variability among wetlands in the strength and nature of these exchanges. Water quality patterns were characterized for lake and tributary end-members and 5-plus wetland locations, and fish use of habitats along the wetland-nearshore continuum was characterized by targeted sampling of resident and migrant species and their potential food sources. The interplay between tributary-water and seiche-water inputs which derives from geomorphic setting -- influenced nutrient and suspended matter concentrations and ratios, with implications for how the wetlands process and transmit watershed-derived materials. The degree to which coastal fishes derived nutritional support and thus translocated materials from wetlands was influenced by a combination of geomorphology and species-specific behaviors. At all sites, wetland- and nearshore-captured fishes obtained substantial nutrition from adjacent habitats. Wetland-nearshore exchanges thus vary along multiple dimensions of landscape setting that should be considered in coastal wetland protection, restoration, and management.