Meeting Abstract
Crude oil exposure can impair cardiorespiratory function in fishes, which can reduce their ability to transport oxygen for production of energy to support aerobic performance. As a result, many fishes experience decreased maximum metabolic rate and overall aerobic performance, which likely influences ecological success. However, oil exposure is not the only environmental stressor that can affect metabolic performance, especially in areas affected by crude oil spills. Hypoxia (low dissolved oxygen) is also known to constrain maximum metabolic rate, yet there has been little effort to explore how hypoxia may influence the magnitude of metabolic injury following oil exposure. Therefore, our goal was to investigate the effects of acute oil exposure and hypoxia on the metabolic performance of red drum, Sciaenops ocellatus, an economically important fish common in the Gulf of Mexico. Here, sub-adult red drum were exposed to crude oil for 24h before being exposed to hypoxic conditions. Our results show that hypoxia exposure combined with crude oil exposure results in significantly reduced aerobic scope (the difference between standard metabolic rate and maximum metabolic rate), which was additive compared to the reductions caused by each stressor alone. Interestingly, our results showed no changes to hypoxia tolerance among individuals, regardless of exposure to hypoxia or oil. We are currently investigating parameters such as hematocrit, mitochondrial enzyme content, and blood oxygen binding affinity to determine the mechanisms driving these additive effects. These data will offer insight into metabolic constraints facing fishes exposed to oil while concurrently subjected to hypoxia, a notable climate change stressor.
