A influência das atividades mineradoras na alteração do pH e da alcalinidade em águas fluviais: o exemplo do rio Capivari, região do carste paranaense The consequences of mining activities on pH alteration in fluvial waters: following the example of Capivari stream, Paraná carstic region

As atividades de mineração causam vários tipos de impactos ao meio ambiente. Este trabalho apresenta um estudo de impacto sobre recursos hídricos superficiais desenvolvidos numa bacia hidrográfica na região metropolitana de Curitiba (PR), onde se observaram modificações no pH e na alcalinidade nas águas do rio Capivari ocorridas num intervalo médio de doze anos. Foram avaliados 387 dias de amostragem da série 1986/1987 e 1.095 dias da série 1998/2000. Comparando-se as duas séries, observou-se que, ao longo deste período (1986-2000), a média do pH elevou-se, em média, 0,5 unidade, enquanto a alcalinidade aumentou em 15%. De 1980 a 2001, as áreas de mineração desta mesma bacia tiveram uma expansão de aproximadamente 47.000 m²/ano. Avaliações ao longo do rio revelaram, nos locais à jusante e mais próximos das pedreiras, que o pH apresenta valores mais altos, tornando-se alcalino, e a condutividade elétrica aumenta. Esses dados confirmam a hipótese de que a expansão das áreas de mineração provocaria alterações nos valores de pH e de alcalinidade das águas do rio Capivari.<br>Mining activities causes many kinds of environmental impacts over environment. In this paper we describe the research developed in the Capivari watershed, in the Curitiba metropolitan region, Paraná, Brazil. Alkalinity and pH changes in Capivari stream over 12 years were observed. The sampling program was performed in 387 sampling day's series at 1986/1987, and another period covering 1,095 days from 1998 to 2000. Comparing these series, the pH average was higher in 0,5 unities and the alkalinity were 15% higher within this period of time. From 1980 to 2001, mining areas of metadolomites spread out to an average rate of 47,000 m²/year. Field evaluations carried out on the Capivari stream showed that in regions close to low water streams and closer to stone-pits, the pH level was higher and it became more alkaline as the electric conductivity increased. These data support the hypotheses that the expansion of mining areas would affect the pH and the alkalinity of the Capivari stream

Crescimento relativo do camar\ue3o canela Macrobrachium amazonicum (Heller) (Crustacea, Decapoda, Palaemonidae) em viveiros

<abstract language="eng">Some morphometric relationships in Macrobrachium amazonicum (Heller, 1862) reared in earthen ponds were studied. A total of 239 individuals were collected, sexed and sorted to juvenile or adult. Total length (Lt), post-orbital length (Lpo), carapace length (Lcp) and queliped length (Lql) were measured. The relationships Lt/Lpo, Lpo/Lcp and Lt/Lcp are the same for juveniles, males and females, indicating unchanged growth pattern during post-larval ontogenetic development. While Lt/Lpo showed isometric growth, Lpo/Lcp and Lt/Lcp showed negative allometry. On the other hand, for the Lql/Lcp relationship, juveniles showed isometric growth, females slight positive allometry and males a strong positive allometry. It suggests that the importance of chelipeds may be different in these groups. Quelipeds play important role on food capture and on agonistic, social and reproductive behavior. Therefore, inter and intraspecific interactions may change during prawn growth, even after morphologica