Variação temporal do microfitoplâncton no Canal Estuarino de Santos (SP)

Abstract

An increase in abundance of potentially toxic dinoflagellates in the Santos channel, located in a highly urbanized and eutrophic estuarine complex, was reported in the literature. Prediction of such occurences is essential, but phytoplankton community structure in dynamic estuarine systems are difficult to analyze. In the present work, we attempted to discuss microphytoplanktonic community in relation to physical variables looking for shifts in composition, in time scales of 25 hours. To achieve our goal two surveys were performed on anchored stations during 25 hours (two complete tidal cicles) in the Santos channel, during November 2005 and March/April 2006. Diatom community enhanced in periods of lower current velocity (tide peaks) during dry season, probably due to lower stratification after tidal runs and light availability, while dinoflagellates enhanced after rainfall events, probably due to a higher haline stratification and an increase in dissolved nutrients. The occurrence in high density of Pseudo-nitzschia "seriata" and Prorocentrum minimum reinforces the necessity of a constant monitoring program in the region.

Phytoplankton in a tropical estuary, Northeast Brazil: composition and life forms

“…T. musica and G. balticum are tycoplanktonic estuarine diatoms. Both species are present in other tropical estuaries in Brazil (Fujita and Odebrecht 2007;Leão et al 2008;Santiago et al 2010;Masuda et al 2011), while F. capucina is the only tycoplanktonic freshwater form in the present study, commonly reported in other benthonic substrates (Roberts et al 2004;Antoniades et al 2005). The three diatoms mentioned are in water column due to the high dynamism of the estuarine ecosystem, which induces mixture and resuspension of organisms from the bottom (Fujita and Odebrecht 2007).…”

“…These species are transported downstream by the river's flow (Masuda et al 2011). The occurrence of some freshwater cyanobacteria species in our study show that these species are present in some freshwater ecosystems in Northeast Brazil, mostly in rivers and reservoirs that are components of the watershed of the Capibaribe River (Dantas et al 2012).…”

“…In tropical estuary ecosystems diatoms are the main components of the planktonic flora (Fujita and Odebrecht 2007;Masuda et al 2011;Borges et al 2012). Studies with phytoplankton species demonstrated that the predominance of diatoms in estuarine ecosystems is not only due to its high rate of division, but also to its euryhaline ability (Ribeiro et al 2003).…”

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

“…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).…”

“…Estuaries are hydrodynamic coastal environments, where the freshwater flow of rivers is mixed with the salt water from the oceans causing extensive environmental fluctuations (NASCIMENTO et al, 2003;MASUDA et al, 2011). Those conditions create a biologically productive system, considered "hotspots" in the cycling and export of nutrients, increasing the rates of biological metabolism and the local primary production CALLAWAY et al, 2014;CLOERN et al, 2014).…”