Phosphorus and Nitrogen Content Flashcards
Most aquatic organisms are sensitive to changes in the amount of _______ _______ in the water in which they live.
Dissolved oxygen.
One factor that can affect dissolved oxygen is an increase in _________ ____ _________ in the
water.
Phosphorus and nitrogen (P and N).
Phosphorus and nitrogen are important to all living things, but what in water can cause problems.
Too high a concentration.
Large amounts of phosphorus and nitrogen can enter water systems in different ways. What are the main 2?
Sewage outfalls and runoff from fertilized fields are two possible sources.
Higher concentrations of these P and N in water cause what?
Increased growth of algae and green plants.
As more algae and plants grow (cuz more P and N), what happens? This what becomes what for bacteria that what it.
More die. Dead organic matter become food for bacteria that decompose it.
With more food available (dead plants and algae), what do the bacteria do?
The bacteria increase in number and use up the dissolved oxygen in the water.
When the dissolved oxygen content decreases (cuz bacteria using it), many fish and aquatic insects what?
Cannot survive.
A “clean” lake contains a wide variety of
what? What do they include?
Organisms. These include fish and invertebrates such as mayfly nymphs, stonefly nymphs, midge larvae, and worms.
Added plant nutrients from treated sewage or runoff from fields causes what in a lake for organisms? What can live in these conditions.
Increased growth of algae and plants. Fewer fish and invertebrates can live in these conditions.
(Most P and N in a lake)
Plants increase and die, bacteria help do what? With more food available, the population of bacteria does what. The bacteria need oxygen to survive, so they use up much of the what? The lake is no longer a place where what can live?
Bacteria help decompose them. The population of bacteria increases. They use up dissolved oxygen in the water. No fish and many insects can live.
