Other values recorded include ammonia, chlorine, water hardness (calcium and magnesium), dissolved oxygen and organic carbon.

BBC: Thames archive reveals long nitrate rise

Nutrient overloads lead to low levels of dissolved oxygen in the water, which can kill fish.

WSJ: Connecticut Seaweed: Life Down on the Kelp Farm

Crossing expanses never remotely surveyed, they will gather 2.25 million data points about salinity, water temperature, waves, weather, fluorescence and dissolved oxygen.

WSJ: A New Wave of Ocean Explorers | Marvels

The general goal of this workshop is a focused review and adoption of a minimum set of QC procedures and QC flags starting with in situ dissolved inorganic nutrients (phosphate, nitrate, nitrite, and silicate) and dissolved oxygen.

UNESCO: NATURAL SCIENCES

They concluded that such upwellings might indeed account for the catastrophic fish deaths, but that they would not explain the deaths of insects, reptiles, birds and mammals, since these animals breathe air rather than relying on dissolved oxygen.

ECONOMIST: What killed Fossil Lake?

Levels of dissolved oxygen in deep water have dropped about 20 percent below their long-term average, according to data collected from up to 60 miles from the well at the center of the worst oil spill in U.S. history.

CNN: No signs of 'dead zone' in Gulf, feds say