Historical records from dated sediment cores reveal the multidecadal dynamic of the toxic dinoflagellate Alexandrium minutum in the Bay of Brest (France)
|Author(s)||Klouch Khadidja1, 2, Schmidt Sabine3, Andrieux-Loyer Francoise1, Le Gac Mickael1, Hervio-Heath Dominique4, Qui-Minet Zujaila Nohemi1, Quere Julien1, Bigeard Estelle2, Guillou Laure2, Siano Raffaele1|
|Affiliation(s)||1 : IFREMER, Ctr Brest, DYNECO PELAGOS, BP 70 ZI Pointe Diable, F-29280 Plouzane, France.
2 : Univ Paris 06, Univ Paris 04, CNRS, Equipe DIPO,Stn Biol Roscoff,Adaptat & Divers Mil, Pl Georges Teissier,CS90074, F-29688 Roscoff, France.
3 : Univ Bordeaux, EPOC UMR5805, F-33605 Pessac, France.
4 : IFREMER, RBE, SG2M, Lab Sante Environm & Microbiol, F-29280 Plouzane, France.
|Source||Fems Microbiology Ecology (0168-6496) (Oxford Univ Press), 2016-07 , Vol. 92 , N. 7 , P. fiw101|
|WOS© Times Cited||23|
|Keyword(s)||paleoecology, ancient DNA, real-time PCR, harmful algal blooms (HAB), dinoflagellates, coastal ecology|
|Abstract||The multiannual dynamic of the cyst-forming and toxic marine dinoflagellate Alexandrium minutum was studied over a time scale of about 150 years by a paleoecological approach based on ancient DNA (aDNA) quantification and cyst revivification data obtained from two dated sediment cores of the Bay of Brest (Brittany, France). The first genetic traces of the species presence in the study area dated back to 1873 ± 6. Specific aDNA could be quantified by a newly-developed real-time PCR assay in the upper core layers, in which the germination of the species (in up to 17–19 year-old sediments) was also obtained. In both cores studied, our quantitative paleogenetic data showed a statistically significant increasing trend in the abundance of A. minutum ITS1 rDNA copies over time, corroborating three decades of local plankton data that have documented an increasing trend in the species cell abundance. By comparison, paleogenetic data of the dinoflagellate Scrippsiella donghaienis did not show a coherent trend between the cores studied, supporting the hypothesis of the existence of a species-specific dynamic of A. minutum in the study area. This work contributes to the development of paleoecological research, further showing its potential for biogeographical, ecological and evolutionary studies on marine microbes.|