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Temperature
(Adapted from The Streamwatch Manual – 3rd Edition)
Definition
Water temperature is a measure of the degree of hotness or coldness of a body of water. Temperature is measured in degrees Celsius (°C).
Why test temperature?
Temperature has a major influence on the biological activity and growth of aquatic organisms.
Temperature affects:
- The rate of photosynthesis of plants
- The metabolic rate of aquatic animals
- Rates of development, timing and success of reproduction
- Mobility of aquatic organisms
- Migration patterns of aquatic organisms
- The amount of oxygen that can be dissolved in the water
- The sensitivity of organisms to toxins, parasites and diseases
All species of aquatic organisms have preferred temperature ranges. As the temperature gets too far above or below the preferred range, the number of species and the number of individuals of a species decreases until finally there are few, or none.
Water temperature is affected by depth, flow rate, amount of sunlight or shade, turbidity, altitude, season, time of day, incoming waters and overland flow (stormwater runoff flowing over hot surfaces in urban areas will warm receiving waters).
Equipment needed
- Alcohol thermometer
- Recording sheets
Method
- Hold the thermometer in the water for at least 1 minute.
- Read the temperature while the thermometer’s bulb is still in the water.
- Record the result on the recording sheets.
Updated: 04 Jan 2012