
Characterization of phytoplankton biodiversity in tropical shipwrecks off the coast of Pernambuco, Brazil
2010; Sociedade Botânica do Brasil; Volume: 24; Issue: 4 Linguagem: Inglês
10.1590/s0102-33062010000400007
ISSN1677-941X
AutoresDouglas Henrique Cavalcanti dos Santos, Maria da Glória Gonçalves da Silva-Cunha, Marilene Felipe Santiago, José Zanon De Oliveira PASSAVANTE,
Tópico(s)Coral and Marine Ecosystems Studies
ResumoThe phytoplankton community was studied around two artificial reefs (shipwrecks Servemar-X and Servemar-I), located off the coast of Pernambuco, northeastern Brazil, aiming to identify and thus, better describe these environments. Water samples were collected with Nansen bottle at three depths (surface, mid-column and bottom) for chlorophyll a analysis and salinity; temperature and water transparency were also measured. To collect phytoplankton samples, a diver using SCUBA equipment carried out phytoplankton hauls with a 20 µm net around the shipwrecks, about 1.5 m from the bottom for approximatly 3 minutes. Chlorophyll a concentrations at the bottom varied between 0.61 and 5.97 mg.m-3, with an average that indicates a mesotrophic environment. Temperature and salinity registered small seasonal variation, while water transparency showed a seasonal spatial pattern positively related to Chl-a rates. As regards the phytoplankton community, diatoms were the most representative group in the samples, followed by dinoflagellates, and among the species, the cyanobacteria Trichodesmium thiebautii Gomont ex Gomont prevailed quantitatively. The ecological importance of these ecosystems was confirmed by the high diversity and evenness indexes, with the influence of coastal waters playing an essential role in phytoplankton structure and diversity.
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