River-plume use during the pelagic larval stage benefits recruitment of a lentic fish

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 67; no. 6; pp. 987 - 1004
• Main Authors: Reichert, Julie M, Fryer, Brian J, Pangle, Kevin L, Johnson, Timothy B, Tyson, Jeff T, Drelich, Alison B, Ludsin, Stuart A
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.06.2010; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Environmental aspects; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fish; Fish industry; Fisheries; Fisheries management; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Lakes; Perca flavescens; Plankton; Rivers; Synecology; Water temperature; Lake Erie; Great Lakes of America; North America; America; Canada; USA, Ohio, Maumee R; North America, Erie L; Temperature; Biology; Lentic environment; Plume; Rivers; Polynya; Pelagic zone; Freshwater environment; Vertebrata; Free water; Fixation; Larva; Pisces; Population recruitment; Nutrient; Stream; Teleostei; Perca flavescens; Osteichthyes
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/F10-036

Similar to coastal marine systems, Lake Erie exhibits open-water river plumes that differ physicochemically and biologically from surrounding waters. To explore their importance to yellow perch ( Perca flavescens ) recruitment in western Lake Erie, we tested two related hypotheses: (i) contributions of larvae to the juvenile stage (when recruitment is set) would be greater from nutrient-rich Maumee River plume (MRP) waters than from less-productive non-MRP waters;; and (ii) warmer temperatures and higher zooplankton (prey) production in the MRP (versus non-MRP waters) would underlie this expected recruitment difference through "bottom-up" effects on larval growth. Peak larval yellow perch density was 10-fold and 5-fold less in the MRP than in non-MRP waters during 2006 and 2007, respectively. However, otolith microchemical analyses demonstrated that disproportionately more juvenile recruits emanated from the MRP than from non-MRP waters during both years. Although temperature and zooplankton production were higher in the MRP than in non-MRP waters during both years, observed recruitment differences were not definitively linked to bottom-up effects. Top-down effects also appeared important, as high turbidity in the MRP may offer a survival advantage by reducing predation mortality on larvae. Our research highlights the need to better understand biophysical coupling in freshwater systems and demonstrates how stochastic tributary inputs can influence fish recruitment.