New Gray Lab Publication!

We are excited to finally get to announce our newest lab publication, “Visual detection thresholds in two trophically distinct fishes are compromised in algal compared to sedimentary turbidity” in Conservation Physiology!

Over the past few summers, as part of my Ph.D. research, I have had the opportunity to work with undergraduates Andy Oppliger and Caroline McElwain on a project focusing on the visual sensitivity, or ability to determine contrast, of Lake Erie fishes. We were able to utilize the optokinetic response, or the innate response of fishes to follow a moving stimulus, to determine at what level of turbidity at which fish can no longer see. One of our goals was to determine the differences between the effects of sedimentary and algal turbidity on the visual sensitivity of Emerald Shiner and Walleye. We found that visual detection thresholds, or the point at which the fish can no longer see, were significantly lower in algal turbidity compared to sedimentary turbidity for both Walleye and Emerald Shiner.

Read the full article here:


Chelsey Nieman


Jeremy Evans- Ponds Project

This summer was the start of a new project in the Gray Lab. I am the Graduate student heading up this research and so far, I have been assisted by Christian Bower, Chris McMahon, Taylor Hrabak and Brynne Drohan. Our fieldwork consists of monitoring water quality, macroinvertebrate community structure, and the general condition of fish populations across a gradient of managed and unmanaged ponds. We spent our summer collecting data and water samples in the field for one week and then running tests on the water samples in the lab the following week. The data we collected this summer will provide a solid baseline for further studies looking at the effects of pond management on the resident fish populations.



Visual Ecology of Lake Erie Walleye with Andy Oppliger

My name is Andy Oppliger, I was fortunate enough to spend my summer at Stone Laboratory studying how turbidity (i.e. suspended particulates in the water column) alters the visual ecology of Lake Erie Walleye (Sander vitreus). The ability of an animal to distinguish between an object and its background (i.e. visual sensitivity) is expected to be altered by increasing turbidity due to both decreased light penetration and a change in the color of light underwater. My objective is to determine if varying turbidity types – algal or sedimentary – differentially influence visual sensitivities of adult Walleye. To determine how visual sensitivity is impacted by turbidity, an optomotor response apparatus was constructed (see photos below) to establish visual thresholds. This study contributes to our understanding of how Walleye populations may respond to changes in Lake Erie’s turbidity.