Gulf of California 2015, Leg 2 – Midwater Ecology
February 22-March 3, 2015
The second leg of this expedition will be concentrated in the Gulf of California’s central and southern basins to better understand the oxygen minimum zone in this area and its influence on the ecology and physiology of midwater animals.
Researchers on this leg hypothesize that the unusual composition, vertical distribution, and migration patterns of the Gulf of California’s midwater fauna are driven chiefly by the characteristics of the oxygen minimum zone (OMZ), which vary from basin to basin within the Gulf. The effects of hypoxic (low oxygen) water include physiological and behavioral adaptations that allow some species to inhabit the OMZ during daylight hours, vertical distribution patters for some species that are compressed above the OMZ, and unusual diel vertical migration cycles.
To investigate these issues researchers will determine the vertical distribution, migration and abundance patterns of the principal midwater species, measure their oxygen consumption rates, observe their behavior and activity levels in situ, and study their trophic linkages.
Quantifying the relative abundance and distribution of species in the Gulf and their adaptations to their extreme environment will provide important data which can be used to anticipate how other seas will be affected by ongoing changes that lead to similar conditions such as warming and acidification.