Ocean acidification increases the accumulation of toxic phenolic compounds across trophic levels

Chair: Ana Queiros

Peng Jin(1,2), Tifeng Wang(1), Nana Liu(1), Sam Dupont(3), John Beardall(4), Philip W. Boyd(5),Ulf Riebesell(6) & Kunshan Gao(1)

1 State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China.
2 Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
3 Department of Biological and Environmental Sciences, University of Gothenburg, 566 Kristineberg, Fiskeba¨ckskil 45178, Sweden.
4 School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
5 Institute for Marine and Antarctic Studies and Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7005, Australia.
6 GEOMAR Helmholtz Centre for Ocean Research Kiel, Dusternbrooker Weg 20, 24105 Kiel, Germany.
Correspondence and requests for materials should be addressed to K.G. (email: ksgao@xmu.edu.cn).

Increasing atmospheric CO 2 concentrations are causing ocean acidification (OA), altering carbonate chemistry with consequences for marine organisms. Here we show that OA increases by 46 to 212% the production of phenolic compounds in phytoplankton grown under the elevated CO2 concentrations projected for the end of this century, compared to the ambient CO2 level. At the same time, mitochondrial respiration rate is enhanced at the elevated CO2 by 130-160% in a single species or mixed phytoplankton assemblage. When fed with phytoplankton cells grown under OA, zooplankton assemblages have significantly higher contents of phenolic compounds, by about 28-48%. The functional consequences of the increased accumulation of toxic phenolic compounds in primary and secondary producers have the potential to have profound consequences for marine ecosystem and seafood quality, with a possibility that fisheries industries could be influenced as a result of progressive ocean changes.