IMAGINE that you’re walking along a path in the middle of a prairie, minding your own business. As you’re walking, you find yourself getting out of breath; you find you’re unable to exert yourself as you can’t seem to breath fast enough. Pretty soon you start becoming slovenly, slow moving, dulled; there’s something wrong with the air, there’s not enough oxygen; you’re in the ‘dead zone‘. You try to move away from where you are, but you don’t know where the bad air started. Before long, it’s too late.
A similar experience may happen to deep ocean fish. They need oxygen too, they just manage to get it from the water, but there’s a problem. A report in the April 17th edition of Science, by Peter Brewer and Edward Peltzer (Monterey Bay Aquarium Research Institute, Moss Landing) describes how ‘Ocean “dead zones” [defined as regions where normal respiration is greatly limited and the expenditure of effort is physiologically constrained], devoid of aerobic life, are likely to grow as carbon dioxide concentrations rise.’ In order to understand what their report is about, we need a little background.
Mental Indigestion 