BRITO, D. V. S.; http://lattes.cnpq.br/6240080177206304; BRITO, Daniela Vasconcelos de Souza.
Résumé:
The Bodoeongo river (Paraiba State) is in the Medium Paraiba river basin. This
region is part of the Drought Polygon and characterized by the irregularity of rain
distribution and for the succession of droughts. Its basin extends for 981 km2; this river
starts at the municipal district of Puxinana (7 33 S, 35 57 W) in an altitude of 691 m above
sea level and it extends for 78 km in the north-south direction ending in the Paraiba river in
Barra of Santana at 310 m above sea level. Its regional importance is due to the intense use
of those waters by the riverine population (unrestricted irrigation, bricks production,
clothes washing and recreation) and because is part of the macro drainage system of the
city of Campina Grande (the second largest city of the state, with 360.000 hab). Along its
course receives punctual and diffuse contributions of domestic sewage and of some
industries. The present study aimed the viability of zooplanktonic species use as biological
indicators of pollution/eutrophication level of the river, to correlate the species identified
with the physical and chemical variables and to study the spatial and temporal distribution
of these species along 7 sampling points in the river (along the Medium and Low
Bodoeongo river) which were monitored monthly from december/99 to november/00. The
physical and chemical parameters (pH, temperature, electric conductivity, dissolved
oxygen, BOD5, suspended solids and fractions, among other) followed APHA (1995)
recommendations except for nitrate (RODIER, 1975). The zooplanktonic community was
studied in samples collected with plankton net (mesh of 50um) and preserved with formal
in sugar 4% solution. The Shannon-Weaver Diversity Index and Euclidian Relative
Distance were calculated. The results showed that the zooplanktonic community was
characterized by the predominance of Rotifera followed by the Copepoda and Cladocera.
The predominant species of Rotifera is B. angularis chelonis, B. caudatus, B. calyciflorus
and Filinia longiseta were typical species of eutrophic environment. The lowest diversity
index were found in the Medium Bodoeongo river (hipereutrophic). The highest densities
of Rotifera were observed during the drought period, which reached values as high as 850
ind/L. The physical and chemicals variables characterized the river as strongly polluted
similar to domestic sewage. The river was included in the Class 4 of CONAMA (20/86)
being not suitable for the activities developed in its margins.
