Which of the following is NOT a water quality factor for ex-situ nurseries?

In the context of ex-situ nurseries, several water quality factors play a crucial role in the successful growth and maintenance of coral. Among these factors, pollutant concentration is crucial for healthy coral ecosystems, as high levels of pollutants can seriously disrupt coral health and development.

Dissolved organic carbons, temperature, and aragonite saturation state all directly affect coral growth in nurseries. Dissolved organic carbons can be an important nutrient source, while temperature influences metabolic rates and overall health. Aragonite saturation state is critical for the calcification process, impacting how well corals can grow and thrive, given that corals rely on the availability of carbonate ions to form their calcium carbonate structures.

However, while pollutant concentration is indeed a vital concern within aquaculture and environmental management, it is not typically categorized as a water quality factor specifically monitored in the same manner as the other options when it comes to ex-situ nursery systems. Instead, ex-situ nurseries typically focus on more direct factors influencing growth and health, such as the others mentioned. Therefore, identifying pollutant concentration as an outlier among the core water quality considerations is logical in the context of managing an ex-situ nursery environment.