Vertical migrator aerobic scope

We propose to measure the temperature- and oxygen dependency of aerobic scope and to use a recently derived relationship between metabolic traits to model the corresponding metabolically available habitat for several dominant vertical migrators. In contrast to coastal species, we hypothesize that diel migrators experience unique selective pressures across their depth range and, as a result, aerobic scope is enhanced at high temperature. To test these hypotheses and map their real world implications we need to 1) measure the active and resting metabolic rates of multiple migratory species across a range of temperatures and oxygen levels, 2) compare the biogeography modeled from metabolic traits with the actual distribution of migrators, and 3) determine whether aerobic scope, beyond the proposed benchmark level, influences performance (e.g. survival and recovery from hypoxic stress), which likely influence fitness and biogeography. In conjunction with a novel depth sampling strategy and acoustic and hydrographic measurements, the proposed physiological measurements will provide insight into the energetic constraints and opportunities that influence native and future habitats. We have proposed two cruises, 21 days each, both in Guaymas Basin, Gulf of California.