Water Temperature Variations
Water Temperature Variations is an obvious ecological factor which should reveal effects in seasonal changes in the aquatic flora.
Warmer temperatures prevent water from mixing, allowing algae to grow thicker and faster. Warmer water is easier for small organisms to move through and allows algae to float to the surface faster.
Algae grow best when they receive 10-15 hours of sunlight a day and the temperature stays between 60-80° F.
There are others that seem to require low temperatures since they occur only in winter at low altitudes, and persist for much longer in high altitude streams.
Many of the species that occur in springs are cold water stenotherms.
At the other end of the scale are several species which are confined to hot springs and do not survive at normal temperatures. Others occur only in waters that become warm in summer.
Many species grow primarily in the summer time. These algae require higher temperatures for growth even though they persist throughout the winter.
Elevated temperatures of stream water of 2.5 to 5.5° C have been reported to cause no significant increase in plankton. However, some streams subject only to thermal pollution indicated that blue-green algae became more abundant and green algae less abundant.
The blue-green algae seldom give any trouble unless water temperatures exceed 21° C.
Studies have reported that: blue-greens favor temperatures that range from 15 to 27° C, green algae 10 to 21° C, and yellow-green algae 4 to 10° C.
Other studies cite the best growth temperature of blue-green algae as 30 to 40° C and green algae as 25 to 35° C.
In mixed populations from a normal healthy stream, a large number of species of Diatoms were present at 20° C dominating the algal culture, but at 30° C only two species of diatoms were numerous and blue-green algae predominated.
Some green algae have adapted to extremes of temperature shown by those found in Arctic regions and other species in water at 45° C.
Diatoms appear to grow best at temperatures of 15 to 30° C. For mixed populations from a normal healthy stream a large number of the Diatom species are usually present at 20° C, and dominate the culture.
Temperature acts as a typical controlling factor governing the rate of growth by determining the rate of metabolism.
The concentrations of nutrients shifts the temperature optimum for growth. Temperature rarely plays a direct role in the acclimatization of algae.
End of Water Temperature VariationsMore Controlling Factors of Algae Growth are briefly discussed.
Seasonal Changes and Algae
Turbidity Effects on Light
Scour of Algae
Alkalinity and Algae
Nutrients and Algae
Grazing Aquatic Animals
Next Topics about Algae…
Yellow-Golden-brown Algae and Diatoms
Significance of Algae
Liverworts and Mosses
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Physical Water Quality
Chemical Water Quality
Biological Water Quality
Water Basics 101
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