Aquatic Dead Zones

"Aquatic Dead Zones" or "dead sea areas" is the following map (based on data from the MODIS sensor aboard the Aqua satellite), released today by NASA Earth Observatory , shows an overview of "dead sea areas." Following the reasoning used in drawing the map, is taken as the dead area  occupied by waters in which the ability to hold dissolved oxygen is so low that hardly a marine organism survive in them.

The size and number of marine dead zones—areas where the deep water is so low in dissolved oxygen that sea creatures can’t survive—have grown explosively in the past half-century. Red circles on this map show the location and size of many of our planet’s dead zones. Black dots show where dead zones have been observed, but their size is unknown.