EAPSI: Development of a Novel Method for Monitoring Marine Ecosystem Health Using Red Carotenoid Coloration of Copepods Under Current and Projected CO2 Levels

Weaver Ryan J, Auburn AL

Investigators

Abstract

Aquatic pollutants affect marine animals by inhibiting key physiological processes necessary for normal growth and development. Moreover, projected climate changes may exacerbate the effects of existing stressors on marine ecosystem health. In collaboration with Dr. Yung-Che Tseng, assistant professor of marine organismal physiology and climate perturbation at National Taiwan Normal University, this project will examine the effects of heavy metal toxicity under current and projected CO2 levels on the health of an abundant marine copepod that has bright red carotenoid coloration. Production of red carotenoids is sensitive to environmental stressors, thus, the ability copepods to produce red pigments will serve as a measure of physiological stress induced by environment pollutants. Using carotenoid color as a proxy for environmental stress will provide a simple, inexpensive, and informative measure of marine ecosystem health. The outcome of the proposed research may greatly benefit society by providing a novel way to monitor the health of the world?s oceans. Understanding how cellular responses to environmental stressors manifest in the phenotypes of marine animals will greatly increase our capacity to monitor marine ecosystem health. The marine copepod Tigriopus japonicus is abundant along the Eastern Coast of Taiwan and has been well studied in ecotoxicology. However, the use of its bright red carotenoid coloration as a biomarker for environmental stress has largely been unexplored. Copepods will be exposed to sub-lethal doses of copper under current or elevated CO2 levels in a 96-h acute toxicity test. Mitochondrial function, copper content and carotenoid content will be analyzed and compared to control groups. As copper concentrations increase copepod coloration is expected to decrease from a rich red color to a dull orange-yellow color. This effect is expected to increase greatly under elevated CO2 conditions. This NSF EAPSI award supports the research of a U.S. graduate student and is funded in collaboration with the Ministry of Science and Technology of Taiwan.