Award: OPP-1641198

This project explored the interactive effects of elevated carbon dioxide and temperature on Antarctic Krill (Euphausia superba) energetics. Specifically, we investigated short- (days) and long- (weeks) term effects of these climate-related variables on their metabolism and acid-base status. We conducted two extensive field expeditions at Palmer Station, Antarctica in 2013 and 2014. Krill, as important components in the diet of fish, penguins, and whales, are critical indicators of the health of Antarctic ecosystem. Previous studies have suggested that krill populations are sensitive to enironmental changes including warming and acidification that result from elevated atmospheric CO2. A highly pH-sensitive blood-oxygen transport protein (hemocyanin) suggested the possibility of reduced metabolism and scope for growth. However, our study found no independent effect of CO2 on metabolism despite a reduction in blood pH under elevated PCO2 (800 ppm) and high temperature (3°C). Blood pH was not reduced at ambient temperature (0°C). A small increase in temperature lead to a pronounced elevation in metabolism that could diminish energy available for growth and reproduction. Ongoing studies in collaboration with Rutgers University are exploring the effects of CO2 and temperature on feeding and growth in Antarctic krill. We conducted an outreach and education project called "Planting Antarctica in Kansas" (PARKA) with the goal of bringing marine climate change and polar research to high school students in a land-locked region of the country that may have limited direct exposure to such research. Last Modified: 10/22/2017 Submitted by: Brad A Seibel