Temperature
Temperature is an important indicator of the
general condition of a water body and the
ecosystem it supports. The following physical and
biochemical processes are all affected by water
temperature: dissolved oxygen levels; the rate of
photosynthesis of aquatic plants; the metabolic
rates of aquatic organisms; and the sensitivity of
aquatic organisms to toxic substances, parasites,
and diseases. Changes in temperature can
naturally affect these processes, leading to stress
in organisms and death. Reproductive stages are
the most sensitive to a change in temperature.
The following are some factors that could cause a
change in the temperature of a water body:
weather, riparian shade, water level, dams,
industrial discharges and storm water.
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Example of Riparian Shade at Jamul Indian Village
Understanding the Impact of Temperature Fluctuations: Optimal temperature ranges depend
on the water body. If temperatures are outside the optimal range for the water body for an extended
amount of time, organisms will become stressed and die. For fish, there are two kinds of limiting
temperatures: the maximum temperature for short exposures, and a weekly average temperature that may
vary by time of year and life cycle stage. It would be beneficial to know optimal ranges for the organisms in
the water body. Find out what the tribal, state, or federal standard range for temperature is to use as a
comparison for the data you are collecting.
Monitoring Temperature: There are a
variety of monitoring devices available to
measure temperature. What you select will
depend on the monitoring objectives set forth in
your environmental and monitoring program.
The following equipment options are commonly
used to collect temperature data from the field.
All options should be readily available at
Laboratory supply stores:
• Thermometers
• Meters
• Multi-parameter probes
• Contract Laboratory (if necessary)
For additional information:
www.epa.gov/owow/monitoring/volunteer/stream
Algal bloom is caused by a variety of issues, including
temperature.
For more information, please contact your CWA Project Officer or Kristin Gullatt, Manager of the Water Division, Tribal Office at (415) 972-3432.
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