Realm: Marine
Climate: Temperate
Biome: Temperate Shelf and seas ecoregions
Central latitude: -40.394350
Central longitude: -57.770740
Duration: 3 years, from 2016 to 2019

430 records

52 distinct species

Across the time series Gymnodiniales sp is the most frequently occurring species

Methods

The surveys took place during spring: two oceanographic cruises were conducted on board the R/V Bernardo Houssay, PNA, Argentina (29 September 2016 to 01 October 2016 and 09 October 2017 to 12 October 2017), and one on board the R/V Austral, CONICET, Argentina (15 December 2019 to 16 December 2019; Fig. 1).” [Extracted from Ferronato et al., 2023] Sampling: Surface (5 m) water samples were taken with Niskin bottles attached to a CTD-rosette from oceanographic research vessels. Water samples were fixed with Lugol (final concentration 1%) and used for protistan plankton abundance estimations. Water sample analysis: For abundance estimations, subsamples of seawater from the Niskin bottles were settled in 50-mL sedimentation chambers during 48 h. Then, single cells were counted in the chamber using a magnification of 400 in two inverted microscopes: a Wild M20 and a Zeiss axio vert A1, following techniques of Utermöhl (1958) and Hasle (1978). Organisms not identified at species or genus level were assigned to a higher taxonomic group such as Cryptophyta (phylum) or Amphidomataceae (family), or were grouped into size categories such as nanoflagellates between 10 and 20 ?m, ciliates between 2040 and 4060 ?m, and so on. Species identification was performed on net haul samples under a Zeiss Standard R microscope and a Nikon Eclipse microscope, using phase contrast, differential interference contrast (DIC) and magnification of 1000 x. All protists were counted irrespective of trophic modes, because although phytoplankton are traditionally regarded to derive nutrition through photoautotrophy (e.g., diatoms), some dinoflagellates and ciliates (e.g., Dinophysis and Mesodinium, respectively) and most nanoflagellates (including the coccolithophore Emiliania huxleyi) are known to be mixotrophic (Glibert and Mitra 2022). Moreover, some dinoflagellates and ciliates are strict heterotrophs (e.g., Protoperidinium and Tintinnida, respectively) and are routinely included in phytoplankton counts. For biomass estimation (in ?C L-1), cell dimensions were measured throughout the counting procedure using an ocular micrometer. Thereafter, plankton cell volumes (in ?m3) were calculated assigning simple geometric shapes to species according to Hillebrand et al. 1999, and transformed into carbon content (pg C cell-1) using two different carbon-to-volume ratios, one for diatoms and one for all the other planktonic groups Menden-Deuer and Lessard, 2000. Abundance is measured in cells L-1 Hasle, R. G. 1978. Concentrating phytoplankton. Settling. The inverted microscope method. In Phytoplankton manual. Monographs on Oceanographic Methodology, ed. A. Sournia (Paris: UNESCO), pp. 8896. Utermöhl, H. 1958. Zur vervollkommnung der quantitativen phytoplankton-methodik: Mit 1 Tabelle und 15 abbildungen im Text und auf 1 Tafel. Int. Ver. Theor. Angew. Limnol. Mitt. 9: 138. Hillebrand H, Dürselen CD, Kirschtel D, Pollingher U, Zohary T. Biovolume calculation for pelagic and benthic microalgae. J Phycol. 1999; 35: 403424. Menden-Deuer S, Lessard EJ. Carbon to volume relationships for dinoflagellates, diatoms, and of the protist plankton. Limnol Oceanogr. 2000; 45: 569579.

Citation(s)

@Article{BioTIME_cit628, Study_id = {771}, Citation_id = {628}, Author = {Ferronato, C. and Berden, G. and Rivarossa, M. and Guinder, A. V.}, Journal = {Limnology and Oceanography}, Pages = {2195-2210}, Title = {Wind-driven currents and water masses shape spring phytoplankton distribution and composition in hydrologically complex, productive shelf waters}, Volume = {68}, Year = {2023}, Doi = {10.1002/lno.12413}, Language = {English} }