ClimateWire: Dead zones, or marine areas with levels of dissolved oxygen so low few things can exist, are becoming increasingly common as climate changes and soaring pollution from human populations combine to put record stress on waterways. This trend is alarming in most places, because marine life provides revenue and food security, but in some instances the changes are natural. Landlocked to the north, the Arabian Sea receives less circulation and interchange with outside waters, making most of its life dependent...