Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.18/1103
Título: Cyanobacterial blooms in natural waters in southern Portugal: a water management perspective
Autor: Galvão, Helena M.
Reis, Margarida P.
Valério, Elisabete
Domingues, Rita B.
Costa, Cristina
Lourenço, Dulce
Condinho, Sílvia
Miguel, Rute
Barbosa, Ana
Gago, Conceição
Faria, Natália
Paulino, Sérgio
Pereira, Paulo
Palavras-chave: Cyanobacteria
Freshwater Reservoirs
Água e Solo
Data: 18-Set-2008
Editora: Inter Research
Citação: Aquatic Microbial Ecology 2008;53:129–140
Resumo: This synthesis of 3 studies from 2 regions of southern Portugal (Alentejo and Algarve) was part of a workshop focusing on cyanobacteria held at the SAME 10. The first study monitored impacts of the large Alqueva dam on the Guadiana estuary since 1996, revealing changes in sediment load, nutrient regime and phytoplankton succession. Prior to dam construction, dense cyanobacterial blooms occurred in the upper estuary during summer and fall. After dam construction, chlorophyll concentration, phytoplankton diversity and abundances of cyanobacteria decreased, contrary to predictions. Mycrocystins remained at low levels in the seston and undetectable in water samples, except during summer 2003 when the particulate fraction contained 1 µg l–1, while chlorophyll concentrations and abundances of potentially toxic cyanobacteria remained low. Algarve reservoirs studied since 2001 revealed differences in phytoplankton dynamics. In the western mesotrophic reservoirs (Bravura and Funcho), 40 to 50% of surface samples contained cyanobacterial concentrations of ≥2000 cells ml–1, while over 80% of samples from the eastern oligotrophic reservoirs (Odeleite and Beliche) exceeded this value. Spring blooms were dominated by Oscillatoriales in Odeleite and Beliche and by Chroococcales in Bravura and Funcho. Bloom composition seemed to depend on water temperature and management strategies, while toxin concentrations reflected the increased biomass of toxic species. Finally, phytoplankton communities and microcystin production in 5 Alentejo freshwater reservoirs were studied from May to December 2005 and April to July 2006. Cyanobacterial blooms occurred, with varying intensities, not only during summer but also occasionally in winter. Microcystins were detected in 23% of the samples (n = 51), but without correlation with cyanobacterial biomass. Although Microcystis aeruginosa seemed to be the major producer of microcystins, other potentially toxic species were found. In summary, the varying pattern of cyanobacterial bloom occurrence and toxicity requires a systematic approach to monitoring programs for adequate risk assessment.
Peer review: yes
URI: http://hdl.handle.net/10400.18/1103
ISSN: 0948-3055
Versão do Editor: http://www.int-res.com/abstracts/ame/v53/n1/p129-140/
Aparece nas colecções:DSA - Artigos em revistas internacionais

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
Cyanobacterial blooms in natural waters in southern Portugal Galvao.pdf1,05 MBAdobe PDFVer/Abrir

FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.