Marine animals do indeed require oxygen, and they do indeed get it from the
water - but NOT by pulling the oxygen atoms out of water molecules,
releasing hydrogen!  Oxygen, in the form of 2-atom oxygen molecules, is
dissolved in the water, thatis, molucules of atmospheric oxygen are IN the
water, AMONG the water molecules, and this is the oxygen animals use for
respiration, relesaing carbon dioxide.

Paul M.