Question

what is the effects on sul\nlight on the aqautic life on the nile river

Answer 1

Speaking in generalities because I know nothing about the Nile, but I do study marine biology.
Usually in areas with a lot of sunlight the aquatic plants will like this and flourish. The problem is that too much sunlight could cause an overpopulation of algae in the river, which is called an algae bloom. Algae blooms take oxygen away from the water, which fish need to survive. Fish populations dramatically decrease during this and they die out, along with other organisms.
Aquatic animals will usually like the larger amount of sunlight because it makes it harder for prey to hide and the microorganisms will be abundant for the fish that eat them. Large amount of sunlight=happy aquatic animals. Unless there's an algae bloom.