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

High levels of microbial nutrients in marine environments result in hypoxic regions, harm to bottom-dwelling marine fauna like shellfish, algal blooms, and red tides producing harmful toxins. All listed impacts are correct.

Step-by-step explanation:

The discharge of high levels of microbial nutrients into marine environments has had several negative impacts. These include:

• Production of large hypoxic or anoxic regions as a result of excessive algal growth and subsequent decay, which depletes dissolved oxygen in the water.
• Negative impacts on shellfish and other bottom-dwelling marine animals, which often die due to the lack of oxygen.
• Generation of algal blooms and red tides that produce toxins harmful to marine life and humans, ultimately killing marine mammals and causing economic losses due to the closure of shellfish beds.

Therefore, all of the choices mentioned are correct. Environmental issues such as these are often interconnected, leading to a cascade of deleterious effects on marine ecosystems.