Effects of a cyanobacterial bloom (Cylindrospermopsis raciborskii) on bacteria and zooplankton communities in Ingazeira reservoir (northeast Brazil)
2001; Inter-Research Science Center; Volume: 25; Linguagem: Inglês
10.3354/ame025215
ISSN1616-1564
AutoresMarc Bouvy, Marc Pagano, M Troussellier,
Tópico(s)Aquatic Ecosystems and Biodiversity
ResumoAME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 25:215-227 (2001) - doi:10.3354/ame025215 Effects of a cyanobacterial bloom (Cylindrospermopsis raciborskii) on bacteria and zooplankton communities in Ingazeira reservoir (northeast Brazil) Marc Bouvy1,*, Marc Pagano1, Marc Troussellier2 1Institut de Recherche pour le Développement (IRD), IRD Center Bel Air, BP 1386, Dakar, Senegal 2Lab Ecosystèmes lagunaires, ERS 2011 CNRS, Université Montpellier II, Case 093, Place E. Bataillon, 34095 Montpellier cedex 5, France *E-mail: bouvy@dakar.ird.sn ABSTRACT: Species composition and seasonal succession of some planktonic components were studied through monthly samplings during 2 yr (1997 and 1998) in Ingazeira reservoir, northeast Brazil. Linked to the severe drought in this region (1997 El Niño event) was the dominance of the toxic filamentous cyanobacterium Cylindrospermopsis raciborskii in the phytoplankton in 1998 (96 to 100% of total phytoplankton biomass), with small proportions of heterocytes (12% of filaments). A great part of the variability of the particulate organic carbon (R2 = 83.9%) was explained by changes in the C. raciborskii carbon biomass. A more significant change in bacterial communities was observed in the post-bloom phase when biomass increased due to the appearance of larger size-classes of cell volume. This bacterial size structure may be the consequence of a strong pressure by bacterivores. Among the zooplanktonic groups, rotifers were numerically more abundant throughout the survey, but microcrustaceans, especially the copepods, contributed the highest proportion of the biomass. Despite the low edibility of C. raciborskii (large trichomes; mean of 97 μm, n = 204), zooplankton diversity increased during and after the bloom (March to December 1998). Our data suggest that rotifers and copepods were able to cut up and shorten the filaments to edible size for other zooplankton species, especially the small-bodied herbivorous cladocerans. Thus, in the studied ecosystem, the heterotrophic micro-organism community appeared to be able to develop a strategy to cope with a dominant and relatively inedible algal food source. KEY WORDS: Bacteria · Phytoplankton · Zooplankton · Cylindrospermopsis raciborskii · Reservoir · Brazil Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 25, No. 3. Online publication date: September 28, 2001 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2001 Inter-Research.
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