Effects of UVB radiation on net community production in the upper global ocean

• Published in: Global Ecology and Biogeography
• Main Authors: Garcia-Corral, Lara S., Holding, Johnna M., Carrillo-de-Albornoz, Paloma, Steckbauer, Alexandra, Pérez-Lorenzo, María, Navarro, Nuria, Serret, Pablo, Duarte, Carlos M., Agusti, Susana
• Other Authors: Biological and Environmental Sciences and Engineering (BESE) Division, Marine Science Program, Red Sea Research Center (RSRC), Department of Global Change Research, IMEDEA (CSIC-UIB) Instituto Mediterraneo de Estudios Avanzados, C/Miquel Marques 21, Esporles 07190, Islas Baleares, Spain, Arctic Research Center (ARC), Aarhus University, Ny Munkegade 114, Bldg 1540, DK-8000 Aarhus C, Denmark, Departamento de Ecologıa y Biologıa Animal, Facultade de Ciencias do Mar, Universidad de Vigo, Vigo E-36310, Spain, Area de Biodiversidad y Conservacion ESCET, Universidad Rey Juan Carlos, Tulipan s/n, Mostoles, Madrid 28933, Spain
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley 2016
• Subjects: Global ocean; metabolic balance; net community production; plankton community; surface water; ultraviolet radiation; Arctic; Pacific Arctic
• Online Access: http://hdl.handle.net/10754/622539; https://doi.org/10.1111/geb.12513

Aim Erosion of the stratospheric ozone layer together with oligotrophication of the subtropical ocean is leading to enhanced exposure to ultraviolet B (UVB) radiation in ocean surface waters. The impact of increased exposure to UVB on planktonic primary producers and heterotrophs is uncertain. Here we test the null hypothesis that net community production (NCP) of plankton communities in surface waters of the tropical and subtropical ocean is not affected by ambient UVB radiation and extend this test to the global ocean, including the polar oceans and the Mediterranean Sea using previous results. Location We conducted experiments with 131 surface communities sampled during a circumnavigation cruise along the tropical and subtropical ocean and combined these results with 89 previous reports encompassing the Atlantic, Pacific, Arctic and Southern Oceans and the Mediterranean Sea. Methods The use of quartz (transparent to UVB radiation) and borosilicate glass materials (opaque to most UVB) for incubations allowed us to compare NCP between communities where UVB is excluded and those receiving natural UVB radiation. Results We found that NCP varies when exposed to natural UVB radiation compared to those where UVB was removed. NCP of autotrophic communities tended to decrease under natural UVB radiation, whereas the NCP of heterotrophic communities tended to increase. However, these variations showed the opposite trend under higher levels of UVB radiation. Main conclusions Our results suggest that earlier estimates of NCP for surface communities, which were hitherto derived using materials blocking UVB radiation were biased, with the direction and magnitude of this bias depending on the metabolic status of the communities and the underwater penetration of UVB radiation. This is a contribution to the Malaspina Expedition 2010, funded by the INGENIO 2010 CONSOLIDER programme (ref. CDS2008-00077) of the Spanish Ministry of Economy and Competitiveness. We thank the captain and the crew of R/V Hesperides and the UTM for ...