Algae use much of the oxygen in water.
etrophication
Phosphate
An "algal bloom".
They can stimulate excess plant and algae growth
a lake coverd in algae...
Too many algae or plants will block sunlight, suffocating anything that lives below the surface. You need some plants or algae though, for oxygene production.
rivers and run- off from farmers fields bring extra nutrients into a lake allow increased growth of algae in the water. The result is a population explosion of algae called an algal bloom
Cause animals bacteria need it
Plants and algae can produce a slimy substance in a lake. Blue-green algae is the most dangerous type of algae for a lake to have because it can produce toxins.
It could be a build-up of sediment washed into the lake after heavy rain. Or it could be an increase in microscopic algae turning the water a greenish colour.
planktonic algae and benthic algae
Lake Winnipesaukee in New Hampshire has various types of aquatic plants. In recent years, the lake has seen problems with an exotic milfoil and algae due to an increase in the phosphorus levels in the water.