Phytoplankton community structure in one sector of Guanabara Bay (RJ, Brazil) during 2011 and 2012

Abstract

This study analyzed the temporal variability of phytoplankton assemblages in the surface waters of Guanabara Bay (RJ, Brazil), at six stations in front of Icaraí Inlet from April/2011 to April/2012. Our results highlight the great contribution of diatoms, dinoflagellates and cyanobacteria, represented by 111 taxa typical of estuarine and coastal areas. The coexistence of benthic and planktonic species suggests considerable hydrodinamism in these waters. All variables were homogeneous (p > 0.05) between the stations, but differed between sampling periods. On average, phytoplankton abundance (107 cells.L-1) was higher than that of other estuaries and its temporal behavior was closely correlated (p < 0.01) with diatoms and cyanobacteria. The richness distribution pattern (7 to 27 taxa) was closely correlated (p < 0.01) with dinoflagellates and diatoms. Ninety per cent of all samples presented a low diversity index (< 2.0 bits.cell-1), which indicated the unstable balance of the system, typical of environments subjected to eutrophication. The population structure analysis revealed that 10% of all taxa were resident, 12% visitors and 78% accidental, suggesting the influence of continental and oceanic water influxes. Between the "typical" taxa, the most common were the cyanobacteria of the order Oscillatoriales, the diatoms Ceratoneis closterium (=Cylindrotheca closterium) and Leptocylindrus minimus and the dinoflagellate Prorocentrum triestinum.

Using in situ flow cytometry images of ciliates and dinoflagellates for aquatic system monitoring

“…The ciliates abundance was relatively stable during the day, ranging from 1,13 E+4 cells mL -1 in the evening to 1,59 E+4 cells mL -1 at 11 pm, which is in agreement with the values found by Rezende et al (2015) near the entrance to the Guanabara bay. In contrast, the population of Ceratium sp.…”

Spatial and seasonal variation of microphytoplankton community and the correlation with environmental parameters in a hypereutrophic tropical estuary - Maranhão - Brazil

“…Under these conditions, the local phytoplankton community consists mostly of centric taxa classified as rare and occasional. That is due to the high hydrodynamic environment that can reach areas far from the mouth, that are considered lentic zones (PAIVA et al, 2006;SOUSA et al, 2008;REZENDE et al, 2015;SENA et al, 2015).…”

“…It is a cosmopolitan and euryhaline species, one of the most abundant in estuaries, considered opportunistic in eutrophic environments TENEBAUM, 2010;MASUDA et al, 2011;REZENDE et al, 2015;BARRERA-ALBA et al, 2016). Skeletonema costatum is classified as a harmful species and it is associated with toxic microorganisms in some cases, causing economic losses for aquaculture (KHAN et al, 1998;UNESCO, 2004).…”

Morphometric characterization of Dinophysis acuminata/D. sacculus complex in Guanabara Bay, Brazil

“…Several potentially harmful microalgal species have been reported at high densities in GB: Scrippsiella trochoidea (Stein) Loeblich (Villac & Tenenbaum 2010), Pseudo-nitzschia H. Peragallo spp. (Rezende et al 2015), filamentous cyanobacteria, Prorocentrum Ehrenberg spp. (Villac & Tenenbaum, 2010, and Chattonella B.Biecheler spp.…”

“…The potentially toxic species of the genus Dinophysis (i.e. D. acuminata/ D. sacculus), however, have been described as only occasional and in low densities (Rezende et al 2015). Nonetheless, several studies have recommended the implementation of protocols able to detect Dinophysis sp.…”