CONICET | Buscador de Institutos y Recursos Humanos

The present study shows the results of laboratory experiments addressing the effects of different water qualitieson E. americana´s fecundity and survival. The study was carried out with cultured females, incubated underdifferent water qualities and controlled conditions during ten days (7 ± 2 °C, 14 h light, salinity of 32 ± 2,Tetraselmis sp. and Nannochloropsis sp. as food). Four treatments were established: P = subsurface waterfrom sewage plume of Bahía Blanca city, D = the dissolved phase of P, I = bottom water in the sewage dischargepoint of Bahía Blanca city, and C = water from the low-impacted area of Monte Hermoso, used asa control treatment. Egg production, number of nauplii, number of faecal pellets, survival and fertility-stateof females were evaluated. The differences and relationships among copepod factors, environmental variablesand pollutants levels (cadmium, lead, copper, zinc, chrome and ammonium-phosphate dissolved), wereanalysed among treatment using non-parametric multivariate analysis. The copepod factors showed a negativeassociation with pollutants levels and the turbidity. No mortality was observed in C, P and D treatments,whereas 100% mortality was observed in treatment I. Females from C, showed the highest egg production(22.6 ± 6.5 egg/female.clutch), as well as gonads regeneration and a second egg laying. Egg production, numberof nauplli and faecal pellets were similar for P and D treatments, but significantly lower than those registeredin C. In P treatment, only 40% of females showed regeneration of their gonads for a second egg laying(12.4 ± 2.9 egg/female.clutch) and in D treatment, no female regenerated their gonads for a second egg laying(12.5 ± 3 egg/female.clutch). The results indicate that bioavailable contaminants from dissolved phase ofsewage effluent reduce the fertility in Eurytemora americana, while the bottom water at the sewage dischargesite is undoubtedly lethal for this species.