Effect of CO2, nutrients and light on coastal plankton. IV. Physiological responses

C. Sobrino; M. Segovia; P. J. Neale; J. M. Mercado; C. García-Gómez; G. Kulk; M. R. Lorenzo; T. Camarena; W. H. van de Poll; K. Spilling; Z. Ruan

doi:10.3354/ab00590

Aquatic Biology

via Mailchimp

AB 22:77-93 (2014) - DOI: https://doi.org/10.3354/ab00590

Theme Section: Environmental forcing of aquatic primary productivity

Effect of CO₂, nutrients and light on coastal plankton. IV. Physiological responses

C. Sobrino^1,*, M. Segovia², P. J. Neale³, J. M. Mercado⁴, C. García-Gómez², G. Kulk⁵, M. R. Lorenzo², T. Camarena^6,7, W. H. van de Poll⁵, K. Spilling^6,7, Z. Ruan^8,9

¹Department of Ecology and Animal Biology, Faculty of Sciences, University of Vigo, Campus Lagoas-Marcosende s/n, 36310 Vigo, Spain
²Department of Ecology, Faculty of Sciences, University of Málaga, Bulevar Louis Pasteur s/n, 29071 Málaga, Spain
³Smithsonian Environmental Research Center, Edgewater, Maryland 21037, USA
⁴Spanish Institute of Oceanography, 29640 Fuengirola, Spain
⁵Department of Ocean Ecosystems, Energy and Sustainability Research Institute Groningen, University of Groningen, 9747 AG Groningen, The Netherlands
⁶Finnish Environment Institute, Marine Research Center, 00251 Helsinki, Finland
⁷Tvärminnen Zoological Station, University of Helsinki, 10900 Hanko, Finland
⁸Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China
⁹Dipartimento di Scienze dell'Ambiente e della Vita, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy

*Corresponding author: sobrinoc@uvigo.es

ABSTRACT: We studied the physiological response of phytoplankton to the interacting effects of 3 factors affected by global climate change: CO₂, nutrient loading and irradiance. Treatments had a high and low level for each factor: CO₂ was bubbled at 1000 ppm by volume versus present atmospheric values; high nutrient treatments had a combination of inorganic and organic nutrients; and light treatments were obtained by covering the tanks with a single or double layer of screen. We measured esterase activity, oxidative stress (ROS), cell death, DNA damage, photosynthetic efficiency and ¹⁴C assimilation as particulate or dissolved organic material (POC and DOC respectively). Conditions simulating future global change scenarios showed similar chlorophyll-normalized primary productivity as present conditions. The main effect driving phytoplankton physiology was the downregulation of the photosynthetic apparatus by elevated CO₂, which decreased esterase activity, ROS, cell death and DNA damage. Nutrient concentration and light acted as additional modulators, upregulating or contributing to downregulation. The percentage of DO¹⁴C extracellular release (PER) was low (0 to 27%), significantly lower under ultraviolet radiation (UVR) than under photosynthetically active radiation (PAR), and acted mainly to re-equilibrate the internal balance when cells grown under UVR were exposed to PAR. PER was almost 3 times lower under high CO₂, confirming a higher resource use efficiency of phytoplankton under future CO₂ concentrations.

KEY WORDS: CO₂ · Downregulation · Nutrients · Microcosms · Photosynthesis · Phytoplankton · Ultraviolet radiation

Full text in pdf format

Cite this article as: Sobrino C, Segovia M, Neale PJ, Mercado JM and others (2014) Effect of CO₂, nutrients and light on coastal plankton. IV. Physiological responses. Aquat Biol 22:77-93. https://doi.org/10.3354/ab00590

Export citation
Share: Facebook - - linkedIn

Cited by

Previous article Next article

AB 22:77-93 (2014) - DOI: https://doi.org/10.3354/ab00590

Theme Section: Environmental forcing of aquatic primary productivity