Recently there has been a dramatic increase in the number and size of low oxygen (hypoxia) regions in coastal waters worldwide due to human activities, but the long-term impacts of this global change on coastal fisheries and ecosystems are unknown. Marked reductions in egg production and hormone levels are found in Atlantic croaker collected from hypoxic coastal regions which are associated with inhibition of the brain hormone controlling reproduction, gonadotropin releasing hormone (GnRH). These studies suggest hypoxia may target three enzymes in the brain critical for GnRH function, tryptophan hydroxylase, aromatase and neuronal nitric oxide synthase. This project will test the hypothesis that all three enzymes in croaker brains are altered by hypoxia exposure through a specific mechanism resulting in down-regulation of GnRH and reproductive functions. The results are expected to show, for the first time in any vertebrate, the existence of a specific brain mechanism by which hypoxia prevents reproduction as an adaptive mechanism to conserve energy. The results will be valuable for making policy, management and regulatory decisions by resource protection agencies. Undergraduate, graduate and postdoctoral researchers, including underrepresented Hispanic minorities, will conduct independent projects and receive training on all aspects of the research and its analysis, the results of which will be communicated via different media to the general public, high school students, teachers and scientific community. Trainees will be taught how their basic research findings can be utilized to benefit society by developing their skills in recognizing the potential broader societal impacts of their research.
