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TitleDinoflagellate cyst production in the Cariaco Basin: a 12.5 year-long sediment trap study
AuthorBringué, M; Pospelova, V; Tappa, E J; Thunell, R C
Source51st Annual Meeting of AASP-The Palynological Society - CAP joint meeting; 2018 p. 1-2
Year2018
Alt SeriesNatural Resources Canada, Contribution Series 20180177
Meeting51st Annual Meeting of AASP-The Palynological Society - CAP joint meeting; Calgary, AB; CA; August 5-10, 2018
Documentbook
Lang.English
Mediadigital
File formatpdf
ProvinceOffshore region
AreaCaribbean Sea; Venezuela
Lat/Long WENS -66.2500 -64.0000 11.2500 10.0000
Subjectsmarine geology; surficial geology/geomorphology; sedimentology; geochemistry; marine organisms; taxonomy; marine sediments; depositional environment; sedimentation; oceanography; water circulation patterns; sea water geochemistry; Cariaco Basin; Dinoflagellates; phytoplankton; microzooplankton; 1997-98 El Niño; microbiology; upwelling
ProgramScience laboratory network coordination, Science laboratory network
Released2018 08 05
AbstractSeasonal and interannual variability in dinoflagellate cyst production were assessed using a 12.5 year-long sediment trap time series from the Cariaco Basin (southern Caribbean Sea). This study constitutes the longest such time series published to date, providing robust patterns of variability for individual dinoflagellate cyst taxa as well as for major phytoplanktonic and (micro-)zooplanktonic groups at the site. Cyst production is interpreted in the context of physico-chemical properties measured in situ at the mooring site (primarily reflecting seasonal upwelling), and considering potential interactions with other major components of the pelagic food web (e.g., diatoms, ciliates, copepods).
The time series consists in > 300 sediment trap samples, each representing ~ 14 days of sedimentation, collected at the CARIACO station between Nov. 8, 1996 and May 19, 2009. Mass fluxes of biogenic silica, calcium carbonate and organic carbon reflect dominantly the timing and strength of wind-driven, seasonal upwelling that brings colder, nutrient-rich waters to the surface, fostering primary productivity and the export of biogenous materials to the depths. On seasonal time scales, dinoflagellate cyst production is closely coupled with upwelling strength, with higher cyst fluxes consistently observed under active upwelling conditions (average of 50.5 × 103 cysts m-2 day-1) compared to non-active upwelling intervals (29.0 × 103 cysts m-2 day-1). Year-to-year variability is characterized by a large increase in cyst production observed over the last ~ 4 years of the time series (2006-2009) and minimum cyst fluxes recorded in the years 1998 and 1999, following the strong 1997/98 El Niño event.
Dinoflagellate cyst assemblages are dominated by Brigantedinium spp. (59.1 %), accompanied by Echinidinium delicatum (10.6 %), Bitectatodinium spongium (8.6 %), Spiny brown type A (3.0 %) and Echinidinium spp. (2.4 %). Most cyst taxa are associated with active upwelling conditions (e.g., Bitectatodinium spongium, Brigantedinium spp., Echinidinium delicatum, Quinquecuspis concreta, Selenopemphix quanta), with some showing higher fluxes under active but weak upwelling conditions (e.g., Echinidinium granulatum, Spiny brown type A). Other cyst taxa tend to show higher abundances at the onset of upwelling conditions (e.g., Echinidinium aculeatum, cyst of Protoperidinium stellatum) or following active upwelling intervals (e.g., Lejeunecysta marieae, Selenopemphix nephroides). The detailed response of each dinoflagellate cyst taxon to environmental variability is presented in the form of an atlas, providing photomicrographs and detailing overall monthly production, contribution to the total trap assemblage as well as cyst production over the 12.5 years of the time series.
Summary(Plain Language Summary, not published)
This study constitutes the longest sediment trap time series in the world detailing seasonal and interannual dinoflagellate cyst production. Over 300 observations of dinoflagellate cyst production were interpreted in the context of parameters (e.g., temperature, nutrients) measured at the site and in light of other major components of the marine food web. This improves considerably our knowledge on the ecology (environmental preferences and trophic ineractions) of dinoflagellates, which, in turn, allows for more detailed interpretations of (fossil) dinoflagellate cyst assemblages found in sediments worldwide.
GEOSCAN ID311128