The reef ecosystem of Serrambi (Pernambuco State, Brazil): phytoplankton composition

Abstract

The reef ecosystem of Serrambi is composed of fringe-type  sandstone reefs that stand out because of  their high biodiversity, artisanal  fishing, water sports and recreational facilities. In order to evaluate the environmental conditions of this system, the structure of phytoplankton community was analyzed through samples taken in  three months of the dry season and three of the rainy season, on  the surface in spring tides during low tide and high tide during the day. The microphytoplankton community was represented by 159 taxa distributed among the divisions Chlorophyta and Euglenozoa with 1 taxon each ( representing  0.63 %),  Cyanobacteria , with  8 taxa ( 5.03%);  Dinofagellata , with  18 taxa ( 11.32%) ; Bacillariophyta , with  131 taxa identified ,  accounting for 82.38 %.  The species that stood  out as dominant were Asterionellopsis glacialis ,  Coscinodiscus sp ., Paralia sulcata ,  Thalassionema nitzschioides; and as very  common , Oscillatoria princeps ,  Oscillatoria sp.,  Protoperidinium sp.,  Prorocentrum micans ,  Surirela fastuosa ,  Coscinodiscus sp.,  Grammatophora marina ,  Nitschia longissima ,  Paralia sulcata ,  Petroneis humerosa ,  Pleuro/Gyrosigma sp.,  Thalassiosira  leptopus ,  Bacillaria paxillifera ,  Biddulphia biddulphiana and  Campyloneis grevillei . According to the ecological pattern, there  is a predominance of tychoplanktonics neritic (48.0 %),  followed by oceanic planktonic ( 21.3%),  neritic planktonic ( 16.5%),  freshwater ( 5.5%)  and estuarine species ( 8. 7 %). Therefore, taking into account a high specific range and good distribution of phytoplankton species,  the Serrambi reef ecosystem was found to be an area free of eutrophication.