The following schedule is from the 72nd Annual Conference of the Southeastern Association of Fish & Wildlife Agencies which was held October 21-24, 2018 in Mobile, Alabama.
AUTHORS: Lindsay White, Dennis R. DeVries, James Stoeckel – School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University
ABSTRACT: The diverse assemblages of fishes in the Southeastern United States are frequently subjected to stress from both temperature and hypoxia due to factors such as climate change, drought, and altered flow regimes below dams. Although responses of fish species of recreational and/or production importance have received some attention, little is known regarding the responses of the myriad non-game and non-commercial species. We hypothesized that habitat specialists and habitat generalists would differ relative to the dissolved oxygen threshold below which they switch from aerobic to anaerobic respiration (critical dissolved oxygen concentration, or DOcrit) as well as in their relative ability to maintain a constant respiration rate as dissolved oxygen declines (regulation index, or RI). Specifically, we predicted that habitat generalist DOcrit would be lower and RI would be higher than for habitat specialists. We used a fiber optic respirometry system (Loligo) to measure respiration rates of seven fish species at temperatures ranging from 18 to 30°C. Data were then used to estimate DOcrit and the RI for each species as temperature increased towards their upper lethal limit. Preliminary results indicate that habitat specialists have higher DOcrit and lower RI values with increasing temperature, suggesting that specialist species are are more sensitive to declining oxygen levels than habitat generalists. These findings will be used to inform decisions and conservation planning concerning management of habitats in which these habitat specialists and habitat generalists occur.
