Question

The discharge of high levels of microbial nutrients into marine environments has ________.

1) resulted in the production of large hypoxic or anoxic regions.
2) had negative impacts on shellfish and other bottom-dwelling marine animals.
3) resulted in algal blooms and red tides that have killed marine mammals.
4) All of the choices are correct.

Answer 1

The discharge of high levels of microbial nutrients into marine environments has negative impacts on marine ecosystems, resulting in the production of large hypoxic or anoxic regions, negative impacts on shellfish and other bottom-dwelling marine animals, and algal blooms and red tides that have killed marine mammals.

Step-by-step explanation:

The discharge of high levels of microbial nutrients into marine environments has All of the choices are correct. Excess phosphorus and nitrogen that enter these ecosystems from fertilizer runoff and from sewage cause excessive growth of algae. The subsequent death and decay of these organisms depletes dissolved oxygen, which leads to the death of aquatic organisms such as shellfish and finfish. This process is responsible for dead zones in lakes and at the mouths of many major rivers and for massive fish kills.