Answer:
The lack of oxygen in coastal waters.
Explanation:
Abiotic factors can be defined as the non-living factors of an ecosystem that interact and affect the living ecosystem of that ecosystem, such as temperature, light, oxygen, and water.
The low level of oxygen in coastal water shows a negative impact on marine ecosystem. It leads to increased in death of marine population, change in their growth, reproduction, and behavior.
As oxygen is an abiotic factor, the correct answer is option). the lack of oxygen in coastal waters.
