How can cultural eutrophication alter freshwater ecosystems and best way to describe the Nitrogen cycle and?

Question

the importance of nitrogen fixation to all living organisms ...

Answer 1

eutrophication = too many nutrients.

in the wild, there are not enough food resources to keep every living organism alive. there is competition for resources (survival of the fittest). so in a freshwater ecosystem with too many nutrients this means that too many creatures will survive. it usually means there'll be heaps of algae and little creatures surviving, and but as a pond or lagoon becomes covered in algae, it blocks the whole oxygen/carbon dioxide exchange process, which means there's not enough oxygen in the pond, so big creatures die.

and the nitrogen cycle...i cant quite remember much about this one but google it and you should find something useful :-)