The population pyramid shown represents a community that has been affected by human migration

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.

We can not answer this question because we cannot see the graph,sorry< 3

D. i believe that doesn't even exist.