The present proposal is aimed at predicting the consequences of ocean acidification on ecosystem health and function. Specifically, it addresses the extent to which the combined effects of ocean acidification, global warming and expanding hypoxia may affect energetics of squids. Squids provide a critical link in oceanic food chains, feeding on the massive zooplankton populations and serving as prey to fish and mammalian predators. Their growth rates and maximum sizes are plastic, reflecting the changing ecosystem. As such, they respond quickly to environmental conditions and serve as real time indicators of ecosystem health. Oceanic squids are the only non-calcifying organisms whose sensitivity to ocean acidification was specifically predicted based on highly pH-sensitive oxygen binding by hemocyanin, the blood pigment of squids. Only a single study has tested this prediction, finding that elevated CO2 constrains metabolism and activity levels in the jumbo squid, Dosidicus gigas. The proposed analysis will integrate across levels of performance, from cell, to systemic, to whole-animal function, comparing squid species with variable blood-oxygen binding properties and CO2 exposure histories. It will addresses the combined effects of declining environmental oxygen, increasing oxygen demand due to warming, and reduced oxygen transport due to high CO2 on the function of these "high-performance" invertebrates. These squids are ecologically and commercially important and are believed to be the most CO2-sensitive non-calcifying taxa. The proposed research effort will be complemented by an extensive education and outreach effort in collaboration with the Ocean Exploration Trust and aboard the E/V Nautilus in the Caribbean in summer 2013 and 2014. E/V Nautilus operates under a new paradigm of "telepresence-enabled" expeditions. Satellite and high-bandwidth Internet2 technology transmits data, including remotely operated vehicle (ROV) video feeds, to shore in real time, supporting the participation of science teams around the world and reaching a growing public and student population. Moreover, the Nautilus program is teamed up with the JASON Project that brings marine science to K-12 classrooms via curriculum development. The investigators on this project will contribute time and expertise in ocean acidification to the development of a new curriculum on Climate and Oceanography and develop a webcast for the JASON Live interactive series that will be broadcast from sea with Nautilus.