Life cycle and production of Campsurus notatus (Ephemeroptera, Polymitarcyidae) in an Amazonian lake impacted by bauxite tailings (Para, Brazil)

Between 1979 and 1989, Lake Batata was subjected to +/- 50 000 m(3) d(-1) o f bauxite tailings effluent, which impacted about 30% of the lake's area. T he present research had as its main goal to study the life cycle and second ary production of Campsurus notatus on the tailings-impacted region of Lake Batata. Campsurus notatus is the species most adapted to the conditions im posed by the bauxite tailings. A central site in the impacted region of Lak e Batata was established and sampled at fortnightly intervals between July 1996 and June 1997. The nymphs of C. notatus in the impacted region had a 1 05-day lifespan, with individuals between 2 and 17 mm in length. Estimated secondary production for C. notatus was 2.5 g DW m(-2) yr(-1) in the impact ed region. This was high compared to production rates estimated for other s pecies of ephemeropterans, indicating the degree of successful adaptation o f C. notatus to the conditions imposed by the bauxite tailings.