Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption |
| |
| Authors: | JAMES J ROBERTS PAUL A GRECAY STUART A LUDSIN STEVE A POTHOVEN HENRY A VANDERPLOEG TOMAS O HÖÖK |
| |
| Institution: | 1. School of Natural Resources and Environment‐Cooperative Institute for Limnology and Ecosystems Research, University of Michigan, Ann Arbor, MI, U.S.A.;2. Department of Fish Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, U.S.A.;3. Department of Biological Sciences, Salisbury University, Salisbury, MD, U.S.A.;4. Great Lakes Environmental Research Laboratory‐National Oceanic and Atmospheric Administration, Ann Arbor, MI, U.S.A.;5. The Ohio State University, Department of Evolution, Ecology, and Organismal Biology, Aquatic Ecology Laboratory, Columbus, OH, U.S.A.;6. Great Lakes Environmental Research Laboratory‐National Oceanic and Atmospheric Administration: Lake Michigan Field Station, Muskegon, MI, U.S.A.;7. Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, U.S.A. |
| |
| Abstract: | 1. Previous studies in a variety of ecosystems have shown that ecologically and economically important benthic and bentho‐pelagic fishes avoid hypoxic (<2 mg O2 L?1) habitats by moving vertically or horizontally to more oxygenated areas. While avoidance of hypoxic conditions generally leads to a complete shift away from preferred benthic prey, some individual fish continue to consume benthic prey items in spite of bottom hypoxia, suggesting complex habitat utilisation and foraging patterns. For example, Lake Erie yellow perch (Perca flavescens) continue to consume benthic prey, despite being displaced vertically and horizontally by hypolimnetic hypoxia. 2. We hypothesised that hypolimnetic hypoxia can negatively affect yellow perch by altering their distribution and inducing energetically expensive foraging behaviour. To test this hypothesis, we used drifting hydroacoustics and trawl sampling to quantify water column distribution, sub‐daily vertical movement and foraging behaviour of yellow perch within hypoxic and normoxic habitats of Lake Erie’s central basin during August‐September 2007. We also investigated the effects of rapid changes in ambient oxygen conditions on yellow perch consumption potential by exposing yellow perch to various static and fluctuating oxygen conditions in a controlled laboratory experiment. 3. Our results indicate that, while yellow perch in general avoid hypoxic conditions, some individuals undertake foraging forays into hypoxic habitats where they experience greater fluctuations in abiotic conditions (pressure, temperature and oxygen concentration) than at normoxic sites. However, laboratory results suggest short‐term exposure to low oxygen conditions did not negatively impact consumption potential of yellow perch. 4. Detailed understanding of sub‐daily individual behaviours may be crucial for determining interactive individual‐ and ecosystem‐level effects of stressors such as hypoxia. |
| |
| Keywords: | anoxia bioenergetics eutrophication Great Lakes movement behaviour |
|
|
