Oceanographers are carving up the world’s seas like the last of the holiday turkey. A new 3D map sorts global water masses — from deep, frigid circumpolar waters to the oxygen-starved Black Sea — into 37 categories.
The map groups together marine regions of similar temperature, salinity, oxygen and nutrient levels. It has been available for only a few months, and researchers are still working through how they might use it. But its international team of developers hopes that the map will help conservationists, government officials and others to better understand the biogeography of the oceans and make decisions about which areas to preserve. It could also serve as a data-rich baseline for analysing future ocean changes.
Many existing systems also attempt to classify variations in the ocean, such as lists of large marine ecosystems or the Longhurst biogeographical provinces that are defined by the rate at which ocean life consumes carbon. But these are often limited to surface or coastal ecosystems. The latest effort, known as the ecological marine units (EMUs), is the most detailed attempt yet to cover the global ocean in three dimensions.