||homepage||
Dissolved
Oxygen
Dissolved Oxygen can range from 0-18 parts per million
but most natural water system require 5-6 parts per million support diverse
population Decreases in dissolved oxygen levels can cause changes in the type
and numbers of aquatic macroeinvertabrites which live in a water ecosystem.
species wich cannot tolerate decreases in Dissolved Oxygen levels include mayfly,
stone fly, etc… as dissolved oxygen levels decrease these pollution intolerate
organisms are replaced by the pollution tolerant worms. Dissolved Oxygen is
great to have in waterevery fish needs d.o.If water is too warm, there may not
be enough oxygen in it. When there are too many bacteria or aquatic animal in
the area, they may overpopulate, using D.O in great amounts.If water is too
warm, there may not be enough oxygen in it. When there are too many bacteria
or aquatic animal in the area, they may overpopulate, using D.O in great amounts.Oxygen
levels also can be reduced through overfertilization of water plants by run-off
from farm fields containing phosphates and nitrates (the ingredients in fertilizers)Under
these conditions, the numbers and size of water plants increase a great deal.
Then, if the weather becomes cloudy for several days, respiring plants will
use much of the available D.O. When these plants die, they become food for bacteria,
which in turn multiply and use large amounts of oxygen. Temperature affects
DO like the warmer the water the less the dissolved oxygen the colder the water
the more dissolved oxygen.dissolved oxygen concentrations at one location are
usually higher in the winter than in the summer.During dry seasons, water levels
decrease and the flow rate of a river slows down. As the water moves slower,
it mixes less with the air, and the DO concentration decreases. During rainy
seasons, oxygen concentrations tend to be higher because the rain interacts
with oxygen in the air as it falls.
More sunlight and warmer temperatures also bring increased activity levels in
plant and animal life; depending on what organisms are present, this may increase
or decrease the DO concentration.During photosynthesis, plants release oxygen
into the water. During respiration, plants remove oxygen from the water.