Question

Which would most likely happen if too many nutrients entered an estuary?

A. Nutrients would be used up by the fish and plants, keeping the estuary in balance.
B. Algal blooms would lower dissolved oxygen levels, causing fish to suffocate.
C. Algal blooms would increase, leaving few food resources for fish.
D. Nutrients would sink to the bottom, increasing soil deposition.

Answer 1

The most likely outcome of too many nutrients entering an estuary is that algal blooms would lower dissolved oxygen levels and cause fish to suffocate.

Step-by-step explanation:

If too many nutrients entered an estuary, the most likely outcome would be B. Algal blooms would lower dissolved oxygen levels, causing fish to suffocate. This process is known as eutrophication. The excess nutrients, particularly nitrogen and phosphorus, which often come from agricultural runoff and sewage, lead to the rapid growth of algae. These algal blooms can decrease light penetration and create hypoxic, or low-oxygen, conditions when the algae die and decay. This environment is detrimental to aquatic life, such as fish and shellfish, which may die from lack of oxygen, contributing to the formation of dead zones.