Oceanographers at the University of Rhode Island have found that even slight levels of ocean oxygen loss, or deoxygenation, have big consequences for tiny marine organisms called zooplankton. Zooplankton are important components of the food web in the expanse of deep, open ocean called the midwater. Within this slice of ocean below the surface and above the seafloor are oxygen minimum zones (OMZs), large regions of very low oxygen. Unlike coastal “dead zones” where oxygen levels can suddenly plummet and kill marine life not acclimated to the conditions, zooplankton in OMZs are specially adapted to live where other organisms – especially predators – cannot. But OMZs are expanding due to climate change, and even slight changes to the low oxygen levels can push zooplankton beyond their extraordinary physiological limits.
— source today.uri.edu | Dec 19, 2018