Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

• Published in: PLoS ONE
• Main Authors: Carlos Cáceres, Fernando González Taboada, Juan Höfer, Ricardo Anadón
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2013
• Subjects: Medicine; R; Science; Q; North Atlantic; Northeast Atlantic
• Online Access: https://doi.org/10.1371/journal.pone.0069159; https://doaj.org/article/08df050cd0ed4aceb5688b7ce99bf59f

Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1)), especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1)), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.