Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand

Research reveals that decoupling between phytoplankton growth and microzooplankton grazing significantly enhances productivity on the Campbell Plateau, southeast of New Zealand. Unlike surrounding waters where grazing pressure balances phytoplankton growth, the plateau experiences an imbalance (g:μ0 = 0.48 ± 0.31), allowing substantial primary production to escape grazing control. This decoupling is linked to localized increases in chlorophyll a (chla > 0.52 mg m−3) and larger phytoplankton forms, suggesting alleviation of iron stress. The study, conducted during austral autumn (March 2017), characterized phytoplankton biomass structure, production, and grazing rates, proposing that entrainment of deeper water into the mixed layer regulates bloom onset and fate by altering nutrient supply and grazing pressure.

Gutiérrez‐Rodríguez, A., Safi, K., Fernández, D., Forcén‐Vázquez, A., Gourvil, P., Hoffmann, L., Pinkerton, M., Sutton, P., & Nodder, S. D. (2020). Decoupling Between Phytoplankton Growth and Microzooplankton Grazing Enhances Productivity in Subantarctic Waters on Campbell Plateau, Southeast of New Zealand. Journal of Geophysical Research: Oceans, 125(2). Portico. https://doi.org/10.1029/2019jc015550