Changes in O2 levels in light and dark bottles can be used to measure ocean net ecosystem production (NEP) and gross primary production (GPP) but not net primary production (NPP). Why is this? A. NPP cannot me estimated without measuring changes in CO2 levels.
B. The bottles include both primary producers and heterotophic consumers
C. Dark bottles measure changes caused by autotrophic respiration only
D. Light bottles measure changes caused by heterotrophic respiration only