Which of the following radioisotope was applied to measure the aquatic primary productivity?

Correct option is D

The correct answer is: (d) ¹⁴C Carbon-14 (¹⁴C) is a radioactive isotope commonly used in the carbon uptake method to measure primary productivity in aquatic systems. It helps track the rate at which carbon is fixed via photosynthesis.
Information Booster:
· The ¹⁴C method involves adding labeled carbon to water and measuring its uptake by phytoplankton.
· Primary productivity = the rate of formation of organic matter by autotrophs.
· This method gives insights into ecosystem health and nutrient cycles in aquatic habitats.