Differential habitat use patterns of yellow perch Perca flavescens in eastern Lake Michigan and connected drowned river mouth lakes Taylor J. Senegal a,⇑ , Carl R. Ruetz III b , Gregory M. Chorak c , David J. Janetski d , David F. Clapp e , Gabriel J. Bowen f , Tomas O. Höök a,g a Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA b Annis Water Resources Institute, Grand Valley State University, Muskegon, MI 49441, USA c Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA d Department of Biology, Indiana University of Pennsylvania, Indiana, PA 15705, USA e Michigan Department of Natural Resources, Charlevoix Fisheries Research Station, Charlevoix, MI 49720, USA f Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA g Illinois-Indiana Sea Grant, West Lafayette, IN 47907, USA article info Article history: Received 16 January 2020 Accepted 29 June 2020 Available online 18 July 2020 Communicated by: Joel Hoffman Keywords: Habitat use Yellow perch Stable isotope Drowned river mouth lake abstract Understanding stock structure and habitat use is important for sustainable fisheries management and conservation of genetic and phenotypic diversity. In eastern Lake Michigan, yellow perch Perca flavescens is found in both the nearshore region of Lake Michigan proper and drowned river mouth (DRM) lakes, small estuary-like systems directly connected to Lake Michigan. Recent genetic analyses suggest complex stock structure between these habitats and the potential migration of Lake Michigan yellow perch into the profundal zone of DRM lakes. We quantified carbon (d 13 C) and oxygen (d 18 O) stable isotope ratios of yellow perch otolith cores to index natal origins, and measured muscle d 13 C, nitrogen (d 15 N), d 18 O, and hydrogen (d 2 H) isotope ratios to reflect recent diet and habitat use. Stable isotope ratios of otolith cores and muscle samples support the existence of resident populations in nearshore Lake Michigan and DRM lakes, as well as Lake Michigan migrants using DRM lakes. Most fish caught in DRM lakes that had natal and recent stable isotope values similar to Lake Michigan fish were collected during fall in DRM lake profundal zones. Comparison of otolith core and muscle stable isotope ratios of individual yellow perch suggest that individuals that recently migrated to DRM lakes also spent early life in Lake Michigan. Differential habitat use patterns of yellow perch in eastern Lake Michigan may have important implications for harvest estimates and fishing regulations. Migration by Lake Michigan fish into DRM lakes does not appear to be related to reproduction, and the underlying benefits of these migrations remain unclear. Ó 2020 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. Introduction Distinct habitats often provide differential foraging opportuni- ties, spawning conditions, and refuges from predation. In marine and large lake ecosystems, various habitat types (e.g., pelagic, ben- thic, nearshore) offer distinct resources (Solomon et al., 2011), but there is nonetheless exchange among these habitats. For example, nearshore zones may be influenced by both offshore waters and tributaries (Morrice et al., 2004), and interfaces between nearshore areas and tributaries serve as potential ecotones, where spatially variable environmental conditions may support increased produc- tivity and bidirectional movement of fish and resources (Jude and Pappas, 1992; Trebitz and Hoffman, 2015). Individual fish habitat use in these areas may strongly affect performance (growth, sur- vival, recruitment) and have important implications for fisheries management (e.g., differential regulations across habitats). Individual fish often move among habitats and occupy season- ally different habitats. For some populations, seasonal habitat occupation is consistent among individuals. In other populations, groups of individuals display distinct habitat occupancy patterns. For example, all individuals in populations of pink salmon Oncor- hynchus gorbuscha and chum salmon Oncorhynchus keta migrate from the ocean into tributaries to spawn (Waples et al., 2001). In contrast, species such as brook trout Salvelinus fontinalis (Doucett et al., 2004; Robillard et al., 2011), brown trout Salmo trutta https://doi.org/10.1016/j.jglr.2020.06.021 0380-1330/Ó 2020 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. ⇑ Corresponding author at: 715 W. State Street, West Lafayette, IN 47907, USA. E-mail address: tsenegal13@gmail.com (T.J. Senegal). Journal of Great Lakes Research 46 (2020) 1412–1422 Contents lists available at ScienceDirect Journal of Great Lakes Research journal homepage: www.elsevier.com/locate/ijglr