Examining the effects of hypoxia on Lake Erie yellow perch: Experimentation in molecular and behavioral methods

The central Lake Erie seasonal hypoxic zone creates a potential barrier between benthic foraging fish and their primary food source – benthic invertebrates. Studies suggest that yellow perch (Perca flavecens) roam above the hypoxic hypolimnion, making short forays to the bottom to forage. However, the physiological stresses and behavioral changes undergone by benthic foraging fish under hypoxic conditions are unclear. To better understand these effects, we subjected yellow perch to varying degrees of hypoxia and examined physiological and behavioral changes. We evaluated potential hypoxia markers (proteins known to accumulate under hypoxic conditions) by Western Blot to assess their concentration under varying levels of hypoxia. Preliminary results suggest that HIF-1α (Hypoxic Inducible Factor-1α) levels increase with decreasing dissolved oxygen concentrations as well as increases in the duration of exposure. This suggests that HIF-1α may be a valuable tool in analyzing the physiological stress on fish when foraging in a hypoxic environment. Furthermore, we designed and implemented a hypoxic stratification system that allows for behavioral studies of yellow perch in stratified environments with various hypolimnetic dissolved oxygen concentrations. These analyses may shed light on the consequences of foraging in a hypoxic environment for yellow perch and other economically and ecologically important fishes.