Diatom associations in shelf waters off Paraná State, Southern Brazil: annual variation in relation to environmental factors
subject: Bacillariophyta, Diatoms, Fitoplâncton, Southern Brazil, Southwestern Atlantic, Sul do Brasil, diatomáceas, ecología, phytoplankton, taxonomia
description: The seasonal variation of diatoms in the inshore waters off Paraná State, Southern Brazil was investigated to analyse their temporal dynamics and to detect the main environmental constraints of the planktonic community. Biomass peaks occurred from May to August and from December to March. Among the microplanktonic diatoms, Cerataulina pelagica, Chaetoceros spp., Dactyliosolen fragilissimus, Guinardia striata, Lauderia annulata, Leptocylindrus spp., Pseudo-nitzschia cf. delicatissima, P. australis, Rhizosolenia spp., Skeletonema costatum and Thalassionema nitzschioides were dominant species. Nanoplanktonic diatoms were dominated by Naviculaceae, Nitzschia spp., Thalassiosira spp. and Chaetoceros cf. tenuissimus. Concentrations of most of the species decreased during and just after the blooms of Phaeocystis pouchetii in September and of Coscinodiscus wailesii in April. Based on cluster analysis and interpretations of the environmental parameters monitored, six diatom associations were discerned. Four main environmental factors were attributed as the determinants for the grouping: (a) the stronger influence of the tropical oligotrophic waters of the Brazil Current in spring/summer, (b) the alternation between dry and rainy (nutrient-richer) seasons, (c) the influence of subantarctic waters mixed with coastal ones in fall/winter, bringing cold species and promoting the growth of autochthonous species, and (d) the blooms of nanoplanktonic (Phaeocystis) and microplanktonic (C. wailesii) species.A variação sazonal das diatomáceas em águas neríticas do estado do Paraná, Sul do Brasil, foi investigada para analisar sua dinâmica temporal e detectar as principais forçantes ambientais da comunidade planctônica. Picos de biomassa ocorreram de Maio a Agosto e de Dezembro a Março. As espécies dominantes foram Cerataulina pelagica, Chaetoceros spp., Dactyliosolen fragilissimus, Guinardia striata, Lauderia annulata, Leptocylindrus spp., Pseudo-nitzschia cf. delicatissima, P. austral…
creator: Luciano Felício Fernandes, Frederico Pereira Brandini
source: Brazilian Journal of Oceanography
publisher: Universidade de São Paulo
date: 2004
relation: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-87592004000100003
coverage: Oceanography