What are the consequences of increased nitrogen and phosphorus into water systems?

Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems. Nitrogen is also the most abundant element in the air we breathe. Nitrogen and phosphorus support the growth of algae and aquatic plants, which provide food and habitat for fish, shellfish and smaller organisms that live in water.

Nitrogen and phosphorus are the essential nutrients that promote the growth of aquatic life forms within water systems ( for instance, they promote the growth of algae).

But when there is too much phosphorus and nitrogen into water systems, it can speed up the process of eutrophication ( increase in the concentration of minerals and nutrients, which enhances the growth of algae, which causes algal blooms). Due to this, dissolved oxygen level is declined as not enough light penetrates in the water body. As a consequence, oxygen is not produced while it is consumed more.

This is hazardous for the other life forms such as fishes that are living in the water as not enough level of oxygen is left in the water system.

i think its the first one

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.