SciELO - Scientific Electronic Library Online

vol.85 issue4Effect of environmental factors on the abundance of decapod crustaceans from soft bottoms off southeastern BrazilTransmission rate variation among three B chromosome variants in the fish Prochilodus lineatus (Characiformes, Prochilodontidae) author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Anais da Academia Brasileira de Ciências

Print version ISSN 0001-3765


SOUZA, ELLY R.S. DE  and  PAULA, FRANCISCO C.F. DE. Spatial and Temporal Hydrochemical Variation of a Third Order River Network in a Quasi Pristine Coastal Watershed, at Southern Bahia, Brazil. An. Acad. Bras. Ciênc. [online]. 2013, vol.85, n.4, pp.1357-1370.  Epub Nov 10, 2013. ISSN 0001-3765.


Rio da Serra watershed presents well preserved fragments of rain forest at the headwaters and small farms at middle and final stretches. These features allowed the study of fluvial hydrochemistry, under quasi pristine conditions. Sampling stations were established in order to represent the basin, and visited during dry, intermediate and wet periods. Obtained results are: temperature (22.1 – 28.6 °C); electric conductivity (34 – 52 µS-cm); dissolved oxygen (35 – 110%); pH (3.8 – 7.7); total suspended solids (1.1 – 20 mg-L); chlorophyll (1.0 – 9.2 µg-L); total N (74 – 580 µmol-L); particulate N (60 – 550 µmol-L); N-NO3 (0.1 – 9.3 µmol-L); dissolved organic N (4 -70 µmol-L); total phosphorous (5.3 – 47 µmol-L); particulate P (4.4 – 59 µmol-L); P-PO4 (0.1 – 0.7 µmol-L); dissolved organic P (0.01 – 2.0 µmol-L); silicate (30 -90 µmol-L); fecal coliforms (80 – 700 CFU-100mL). In seasonal terms dissolved oxygen, electric conductivity, nitrate and silicate concentrations were higher during the dry, whereas TSS was higher during the wet period. Seasonal differences of dissolved oxygen, temperature, pH and nitrate were also detected near wetlands areas. Along the basin results showed a distinction between headwaters and other sections, revealing a control of fluvial hydrochemistry by the preserved area, mostly for the dissolved organic N and P species and phosphate.

Keywords : Rivers ecology; dissolved nutrients; biological reserve; wetlands.

        · abstract in Portuguese     · text in English     · English ( pdf )