A new study suggests that human activity is having a devastating effect on oxygen levels in the world’s oceans, and could cause parts of the Pacific Ocean to essentially suffocate in as little as 15 years. Warming ocean waters can’t hold as much oxygen as colder water, and researchers at the National Center for Atmospheric Research (NCAR) say deoxygenation of the ocean’s warmer upper layers will disrupt marine ecosystems in a big way. If greenhouse gas emissions continue at their current rate, it could leave deep sea creatures without enough oxygen to survive.
Matthew Long, an oceanographer at NCAR, is the lead author of a new study that warns of problems ahead. The study’s introduction predicts that “widespread detection of forced deoxygenation is possible by 2030–2040.” The study was co-authored by Curtis Deutsch of the University of Washington and Taka Ito of the Georgia Institute of Technology.
The real problem, of course, is much bigger than just having less oxygen in the water. Like creatures on land, marine animals need oxygen in order to survive. In a healthy ocean environment, phytoplankton in the water’s topmost levels generate oxygen via photosynthesis and then mix into the deep. The plants, fish, and other organisms living in what scientists call the oxygen minimum zones (OMZs) deep below the ocean’s surface may not be able to survive if less oxygen is mixed down from above.
Long and his colleagues say deoxygenation is likely already evident in some parts of the ocean, and that it may be detected in larger swaths of the Pacific Ocean as early as 2030. If left to continue unchecked, the effects of global warming could dramatically upset the ocean’s natural systems, though the impact won’t be evenly spread. The study warns that there has been a “sharp acceleration of oceanic deoxygenation in the first half of the 21st century” but in scientific modeling, some areas of the ocean don’t show deoxygenation trends as far out as 2100. That indicates the impact of oxygen loss will be radically variable from one part of the world to another.
Via Washington Post