Deutsch: Hypoxie / Español: Hipoxia / Português: Hipóxia / Français: Hypoxie / Italiano: Ipossia /

A hypoxia is the Depletion of dissolved Oxygen in water, a condition resulting from an overabundance of nutrients of human or natural origin that stimulates the growth of algae, which in turn die and require large amounts of oxygen as the algae decompose. It was the most frequently cited direct cause of fishkills in the U.S. from 1980 to 1989.
Other /More definition:
A hypoxia is depletion of dissolved oxygen in an aquatic system.
Other /More definition:
A hypoxia is a condition in which the dissolved oxygen in a parcel of water is low enough to have biological effects. Fish and other creatures can survive short periods of hypoxia, but long periods of reduced oxygen can dramatically alter the ecosystem. EPA defines hypoxic water as water with oxygen concentrations of 2 milligrams per liter or less.