GLOBAL warming may be creating a “dead zone” in the Sea of Japan. Rising
temperatures are shutting down a circulation process that is crucial to life
there, say researchers in Japan, and the same problem could affect oceans across
the planet.
In winter, oxygen-rich surface water in the Sea of Japan becomes colder than
the water below and sinks, taking oxygen with it. The oxygen encourages the
growth of bacteria that break down organic matter falling to the seabed. At the
same time, the current brings inorganic matter up from the depths, which plant
plankton feed on.
When this convection…
