EARTH SCIENCE
LIMNOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It assures that light can penetrate the water and allow photosynthesis to occur.
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It prevents algal blooms from occurring in the spring..
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It brings oxygen to the lower depths of the lake and nutrients to the upper levels of the lake.
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It keeps the lake organisms warm throughout the year.
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Detailed explanation-1: -Turnover is a natural way the lake cleans up harmful bacteria and algae. It carries dead algae down into the depths of the lake where there is less sunlight, helping to prevent algae growth. You can think of it as an escalator, moving the algae cells from the top of the lake to the bottom.
Detailed explanation-2: -Seasonal lake mixing Twice a year, unseen forces churn water from the depths of our deeper lakes and deliver oxygen and nutrients essential to aquatic life. This temperature-driven process of lake “turnover” allows aquatic life to inhabit the entirety of the lake as oxygen becomes more available.
Detailed explanation-3: -Autumn Turnover Mixing of the lake increases oxygen by exposing a greater volume of water to the atmosphere. If a substantial portion of the lake volume lost oxygen in the summer, a rapid fall turnover occurs. This can cause fish kills by diluting the oxygen that was available in the surface layer before mixing.
Detailed explanation-4: -During summer stratification the thermocline prevents dissolved oxygen produced by plant photosynthesis in the warm waters of the well-lit epilimnion from reaching the cold dark hypolimnion waters. The hypolimnion only has the dissolved oxygen it acquired during the short two-week spring overturn.
Detailed explanation-5: -Oxygen enters the water in a few ways: First, it is naturally generated by phytoplankton, algae, seaweed and other aquatic plants as they photosynthesize. It can also be mixed into a lake by through aeration, like wind blowing across the water’s surface.