•Measurement of the amount of O2dissolved in water
•DO < 5 ppm: dangerous for
cold water fish
•DO < 1 ppm: anoxic
•Factors affecting DO:
–decomposition,
microbial activity, respiration, turbulence, wind, salinity, temperature
www.mrcirl.org
One of the parameters that
we measured was dissolved oxygen. Dissolved oxygen concentration in a lake
is a measurement of the amount of gaseous oxygen dissolved in the water.
Because organisms rely on this oxygen for respiration, water with a DO
concentration of less than 5 ppm is considered dangerous for cold water
fish. When levels fall below this, fish kill like the one in the picture may
occur. When DO concentration falls below 1 ppm, the water is termed anoxic.
DO levels are affected by many factors, including decomposition, microbial
activity, respiration, turbulence, wind disruption, salinity, and
temperature.