Runoff that contains fertilizers can cause increased levels of nitrogen in the ocean. What is a possible result of these increased nitrogen levels that may have harmful effects that can disrupt the diversity of ocean ecosystems?

Explanation:

Increased nitrogen level in ocean water can lead to excessive growth of aquatic plants in the ocean which in turn leads to high oxygen (dissolved oxygen) uptake by these plants when they decompose. The overgrowth of these plants also prevent light penetration in the ocean water. All these can affect other aquatic organisms particularly those that depend on these dissolved oxygen and/or light penetration (such as fish and crustaceans).

not sure if this is what you'r looking for nnew= nold