title: Biomonitoring of cyanotoxins in two tropical reservoirs by cladoceran toxicity bioassays.
abstract: This study evaluates the potential for the use of cladocerans in biomonitoring of cyanobacterial toxins. Two zooplankton species (Daphnia gessneri and Moina micrura) were cultivated in the laboratory for use in acute (48 h) and chronic (10 days) bioassays. Water samples were collected from two reservoirs and diluted in mineral water at four concentrations. Survivorship in the acute bioassays was used to calculate LC50, and survivorship and fecundity in chronic bioassays were used to calculate the intrinsic population growth rate (r) and the EC50. Analysis of phytoplankton in the water samples from one reservoir revealed that cyanobacteria were the dominant group, represented by the genera Anabaena, Cylindrospermopsis, and Microcystis. Results of bioassays showed adverse effects including death, paralysis, and reduced population growth rate, generally proportional to the reservoir water concentration. These effects may be related to the presence of cyanobacteria toxins (microcystins or saxitoxins) in the water.
authors.affiliation: Laboratório de Avaliação e Promoção da Saúde Ambiental, Departamento de Biologia, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ-CEP 21045-900, Brazil. aloysio@ioc.fiocruz.br
authors.forename: Aloysio
authors.initials: A
authors.lastname: da S Ferrão-Filho
authors.forename: Maria Carolina S
authors.initials: MC
authors.lastname: Soares
authors.forename: Valeria
authors.initials: V
authors.lastname: de Freitas Magalhães
authors.forename: Sandra M F O
authors.initials: SM
authors.lastname: Azevedo
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D001681:Biological Assay / Q000379:methods*; D033361:Cladocera / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D000087522:Cyanobacteria Toxins; D004784:Environmental Monitoring / Q000379:methods*; D008387:Marine Toxins / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D052998:Microcystins / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D012530:Saxitoxin; D013997:Time Factors; D014873:Water Pollutants / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D014881:Water Supply / Q000032:analysis*; D015048:Zooplankton / Q000187:drug effects* / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D014873:Water Pollutants; D012530:Saxitoxin