Variability in the Relationship Between Ocean Phytoplankton Diversity and Carbon Biomass Across Methods and Scales.

The relationship between phytoplankton diversity and carbon biomass varies significantly depending on the assessment method, with a notable difference observed across three measurement techniques.

• Why it matters: Understanding this variability is crucial because phytoplankton play a key role in global carbon cycling, yet in-water observations of their productivity-diversity relationship (PDR) are limited, hindering accurate ecosystem modeling.
• What they did: The study analyzed a global in-situ dataset using three metrics of phytoplankton diversity: hyperspectral remote sensing reflectance, HPLC pigment measurements, and 18S rRNA gene sequences, comparing their relationships with carbon biomass.
• The result: Findings reveal that the method of assessing phytoplankton diversity influences the observed PDR, providing a baseline for future global monitoring efforts, including satellite-based observations from NASA's PACE mission.