Temperature dependence of plankton community metabolism in the subtropical and tropical ocean

by Lara S. Garcia-Corral, Johnna M. Holding, Paloma Carrillo-De-Albornoz, Alexandra Steckbauer, María Pérez-Lorenzo, Nuria Navarro, Pablo Serret, Josep M. Gasol, X. Anxelu G. Morán, M. Estrada, E. Fraile‐Nuez, V. Benítez‐Barrios, S. Agusti, Carlos M. Duarte
Year: 2017

Bibliography

L. Garcia-Corral, J.M. Holding, P. Carrillo de Albornoz, A. Steckbauer, M. Pérez-Lorenzo, N. Navarro, P. Serret, J.M. Gasol, X.A.G. Morán, M. Estrada, E. Fraile-Nuez, V. Benítez-Barrios, S. Agustí, C.M. Duarte. Temperature dependence of plankton community metabolism in the subtropical and tropical ocean.  Global Biogeochemical Cycles, 31, 1141–1154, DOI: 10.1002/2017GB005629

Abstract

Here we assess the temperature dependence of the metabolic rates grossprimaryproduction(GPP, community respiration CR, and the ratio GPP/CR) of oceanic plankton communities. We compile data from 133 stations of the Malaspina 2010 Expedition, distributed among the subtropical and tropical Atlantic, Pacific, and Indian oceans. We used the in vitro technique to measured metabolic rates during 24 h incubations at three different sampled depths: surface, 20%, and 1% of the photosynthetically active radiation measured at surface. We also measured the % of ultraviolet B radiation UVB penetrating at surface waters. GPP and CR rates increased with warming, albeit different responses were observed for each sampled depth. The overall GPP/CR ratio declined with warming. Higher activation energies (Ea) were derived for both processes (GPPChla = 0.97; CRChla = 1.26; CRHPA = 0.95 eV) compared to those previously reported. The Indian Ocean showed the highest Ea (GPPChla = 1.70; CRChla = 1.48; CRHPA = 0.57 eV), while the Atlantic Ocean showed the lowest (GPPChla = 0.86; CRChla = 0.77; CRHPA = −0.13 eV). We believe that the difference between previous assessments and the ones presented here can be explained by the overrepresentation of Atlantic communities in the previous data sets. We found that UVB radiation also affects the temperature dependence of surface GPP, which decreased rather than increased under high levels of UVB. Ocean warming, which causes stratification and oligotrophication of the subtropical and tropical oceans, may lead to reduced surface GPP as a result of increased penetration of UVB radiation.

Keywords

Tropical and Subtropical Oceans Plankton Metabolism Temperature Depth Oligotrophic Gyres Ultraviolet Radiation