Midwest Fish & Wildlife Conference 2019

AUTHORS. Taaja R. Tucker, University of Toledo; Kevin Keeler, Five Rivers Services LLC; Edward Roseman, U.S. Geological Survey; Dylan Jones, U.S. Geological Survey; Scott Jackson, University of Toledo; Stacey Ireland, US Geological Survey

ABSTRACT. The lake sturgeon (Acipenser fulvescens), a state-listed threatened species in Michigan, is a focal species targeted for recovery in the St. Clair-Detroit River System (SCDRS). Since the early 2000s, spawning habitat restoration projects have been completed in seven locations throughout the SCDRS to increase recruitment of lake sturgeon in the system.  Little is known about the feeding habits and the energy requirements of early-life stage lake sturgeon in the SCDRS. Bioenergetics models allow for the creation of energy budgets for individual fish and can extrapolated to fish populations. While bioenergetics models exist for several species and life stages of sturgeon, one has not yet been developed for young lake sturgeon. Measurement of respiration rates is integral to the generation of bioenergetics models. To determine oxygen consumption rates, fertilized lake sturgeon eggs were collected from the St. Clair River, Michigan and reared in the laboratory at the USGS Great Lakes Science Center under a temperature regime closely matching that of the river (13-21°C). Oxygen uptake by larval and juvenile lake sturgeon (1-10 individuals per trial) was measured in a closed, 38mL respirometer (PreSens Fibox 3 fiber optic oxygen meter with OxyView software). Trials were performed in thirty-minute intervals weekly as early as 1-day post-hatch. Routine respiration rates were calculated and compared between sizes (e.g., yolk sac larvae vs. post-yolk sac larvae vs. juvenile) and between those generated for Fish Bioenergetics 4.0 (pallid sturgeon, Scaphirhynchus albus). Further needs for the development of a bioenergetics model for lake sturgeon are discussed.