scholarly journals Protozooplankton characterization of two contrasting sites in a tropical coastal ecosystem (Guanabara Bay, RJ)

2007 ◽  
Vol 55 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Eli Ana Traversim Gomes ◽  
Viviane Severiano dos Santos ◽  
Denise Rivera Tenenbaum ◽  
Maria Célia Villac

Much time and resources have been invested in understanding plankton dynamics in Guanabara Bay (Brazil), but no attention has been devoted to the protozooplankton. To fulfill this lacuna, abundance and composition of protozooplankton were investigated from January to December - 2000 in fortnightly surface water samplings at two distinct water quality sites (Urca - closer to the bay entrance, more saline and cleaner waters; Ramos - inner reaches, hypereutrophic waters). The density at Urca (10³ - 10(5) cell.l-1) was one to three orders of magnitude lower than at Ramos (10(4) - 10(5) cell.l-1). A seasonal trend for nanoplankton and protozooplankton was more evident at Urca, but both sites had lower densities during the colder period. Small heterotrophic dinoflagellates (20-30 mm) were dominant in over 50% of the samples. The protozooplankton abundance and composition reflected the distinct trophic conditions states found at the bay. During the wet-warm season, non-oligotrich ciliates were representative of Ramos site with Gymnodiniaceae dinoflagellates, while tintinnids and heterotrophic dinoflagellates were predominantly found at Urca mainly during the dry-cold season. This first descriptive study towards the understanding of the intricate relationships among the microbial food web components reveals that protozooplankton can be a good indicator of water quality conditions at the bay.

2010 ◽  
Vol 10 (3-4) ◽  
pp. 127-132 ◽  
Author(s):  
Beata Ferencz ◽  
Jarosław Dawidek

Spatial variation of basin supply as a factor of water quality in a shallow, flow-through lake Lake Syczyńskie is a water body that represents a group of the smallest Łęczna-Włodawa Lakes. The lake is supplied with waters from the four streams, while the outlet from the lake is directed into the Świnka River. The residence time of water is very short in Lake Syczyńskie. A role and variation of water supply from the catchment area were calculated using the mean seasonal loads transported from lakes sub-basins. A range of ionic migration into the basin of the lake was presented by means of daily and five-day radiuses. Among all inflows, C2 and C4 streams that drained Chełm Hills structure, were the most stable ones. The C3 stream that drained lake vicinity, was less important in shaping the quality of the lake water, while stream C1 was the one with a wide range of seasonal loads inconstancy. The highest fluviodynamic and matter transport occurred during the cold season. However, during the warm season in-lake processes were significant in terms of shaping the quality of lake water.


Sign in / Sign up

Export Citation Format

Share Document