Federico M. Ibarbalz 1 , Nicolas Henry 2 , 3 , Manoela C. Brandão 4 , Séverine Martini 4 , Greta Busseni 5 , Hannah Byrne 6 , Luis Pedro Coelho 7 , Hisashi Endo 8 , Josep M. Gasol 9 , 10 , Ann C. Gregory 11 , Frédéric Mahé 12 , 13 , Janaina Rigonato 14 , Marta Royo-Llonch 9 , Guillem Salazar 15 , Isabel Sanz-Sáez 9 , Eleonora Scalco 5 , Dodji Soviadan 4 , Ahmed A. Zayed 11 , Adriana Zingone 5 , Karine Labadie 16 , Joannie Ferland 17 , Claudie Marec 17 , Stefanie Kandels 18 , 19 , Marc Picheral 4 , Céline Dimier 1 , 4 , Julie Poulain 14 , Sergey Pisarev 20 , Margaux Carmichael 2 , Stéphane Pesant 21 , 22 , Tara Oceans Coordinators, Marcel Babin 17 , Emmanuel Boss 23 , Daniele Iudicone 5 , Olivier Jaillon 3 , 14 , Silvia G. Acinas 9 , Hiroyuki Ogata 8 , Eric Pelletier 3 , 14 , Lars Stemmann 3 , 4 , Matthew B. Sullivan 11 , 24 , 25 , Shinichi Sunagawa 15 , Laurent Bopp 3 , 26 , Colomban de Vargas 2 , 3 , Lee Karp-Boss 23 , Patrick Wincker 3 , 14 , Fabien Lombard 3 , 4 , Chris Bowler 1 , 3 , 27 , ∗ , Lucie Zinger 1 , ∗∗
14 November 2019
The ocean is home to myriad small planktonic organisms that underpin the functioning of marine ecosystems. However, their spatial patterns of diversity and the underlying drivers remain poorly known, precluding projections of their responses to global changes. Here we investigate the latitudinal gradients and global predictors of plankton diversity across archaea, bacteria, eukaryotes, and major virus clades using both molecular and imaging data from Tara Oceans. We show a decline of diversity for most planktonic groups toward the poles, mainly driven by decreasing ocean temperatures. Projections into the future suggest that severe warming of the surface ocean by the end of the 21 st century could lead to tropicalization of the diversity of most planktonic groups in temperate and polar regions. These changes may have multiple consequences for marine ecosystem functioning and services and are expected to be particularly significant in key areas for carbon sequestration, fisheries, and marine conservation.
Most epipelagic planktonic groups exhibit a poleward decline of diversity
No latitudinal diversity gradient was observed below the photic zone
Temperature emerges as the best predictor of epipelagic plankton diversity
Global warming may increase plankton diversity, particularly at high latitudes
The drivers of ocean plankton diversity across archaea, bacteria, eukaryotes, and major virus clades are inferred from both molecular and imaging data acquired by the Tara Oceans project and used to predict the effects of severe warming of the surface ocean on this critical ecosystem by the end of the 21 st century.