Rees 9723050 Conditions of low oxygen (hypoxia) in fresh, brackish and marine waters are brought about by both natural processes and human activity. Since many important metabolic processes require oxygen, a decrease in oxygen availability is a potentially life-threatening situation for the organisms that live in these environments. One way to compensate for a decrease in oxygen is to shift to metabolic pathways that do not require oxygen. This research will evaluate this response in a common inhabitant of coastal estuaries, the Gulf killifish, Fundulus grandis. The activities of enzymes (the protein molecules that catalyze the reactions of metabolism) will be determined in fish exposed to hypoxia in the laboratory. These measurements will show whether these enzymes change in a manner that reflects an increased reliance upon oxygen-independent metabolic pathways. If the initial phase of this work shows a change in enzyme activity, then the later phase will investigate the mechanism of this change. This research will lead to a better understanding of how this species, and potentially other, commercially important species, respond to environmental hypoxia.
