Net Primary Production (NPP) is calculated using which formula?

Net Primary Production (NPP) is an essential concept in marine science, referring to the amount of organic matter or biomass available for growth after accounting for the energy used by plants for respiration. The formula for calculating NPP incorporates two key measurements: Gross Primary Production (GPP), which is the total amount of organic matter produced through photosynthesis, and respiration (R), which is the energy consumed by the plants in the process of respiration.

In the context of the correct formula, NPP is determined by taking the Gross Primary Production (GPP) and subtracting the energy lost during respiration (R). This relationship can be expressed as NPP = GPP - R. This calculation provides a clearer understanding of how much energy is actually available for subsequent trophic levels in an ecosystem, such as herbivores and higher consumers.

This distinction is crucial because while GPP represents total production, not all of that energy is available for growth or for consumption by other organisms in the food web. By subtracting the energy lost to respiration, we obtain a realistic measure of the energy that contributes to growth and sustains the ecosystem.

Thus, the correct answer highlights the critical importance of understanding energy flow and productivity in marine ecosystems and clarifies how primary