Why is measuring dissolved oxygen important in aquatic ecosystems?

• A. It is used to estimate the pH of the ecosystem.
• B. It determines the salinity levels of the water.
• C. It indicates the availability of oxygen for aquatic organisms to carry out cellular respiration.
• D. It measures the amount of sunlight penetrating the water.

Answer: (C)

Verified step by step guidance

1. Understand the role of dissolved oxygen in aquatic ecosystems: Dissolved oxygen refers to the amount of oxygen present in water, which is essential for the survival of aquatic organisms as they rely on it for cellular respiration.
2. Recognize the connection between dissolved oxygen and cellular respiration: Cellular respiration is the process by which organisms convert glucose and oxygen into energy (ATP), carbon dioxide, and water. Without sufficient dissolved oxygen, aquatic organisms cannot perform this vital process.
3. Eliminate incorrect options: Measuring dissolved oxygen does not directly estimate pH, salinity, or sunlight penetration. These are separate parameters that require different methods of measurement.
4. Focus on the correct answer: Dissolved oxygen is a key indicator of the availability of oxygen for aquatic organisms to carry out cellular respiration, which is critical for their survival and ecosystem health.
5. Conclude the importance: Monitoring dissolved oxygen levels helps scientists assess the health of aquatic ecosystems, detect pollution, and ensure the sustainability of aquatic life.