TOXICIDADE AGUDA DE ALGUNS HERBICIDAS E INSETICIDAS UTILIZADOS EM LAVOURAS DE ARROZ IRRIGADO SOBRE O PEIXE Danio rerio

Pesticides use in paddy rice is a common practice to avoid yield losses due to weeds, insects and diseases. However, not much information is available about the environmental impact of these pesticides in the aquatic systems. The objective of this research was to determine the LC50; 48h of some herbicides and insecticides comonly used in paddy rice and to estimate the risk coefficient (deterministic analysis), classifying the pesticides toxicity using the fish Danio rerio as a test organism. The following pesticides were evaluated: 2,4-D, metsulfuron-methyl, carfentrazone-ethyl, bentazon, quinclorac, clomazone, oxadiazon, oxyfluorfen, bispyribac-sodium, pyrazosulfuron-ethyl, betaciflutrin, carbofuran, fipronil and lambdacialotrin and the LC50; 48h value (mg a.i.L-1) were: 237.1; >100.0; 2.5; 1150.0; 300.0; 13.8; 3.9; 1.2; >100.0; 67.56; 0.004; 1.3; 0.2 and 0.002, respectivelly. The results suggest that the herbicides oxyfluorfen, oxadiazon and clomazone and the insecticides lambdacialotrin, betaciflutrin, carbofuran and fipronil are the chemicals with the highest ecological impact risk to the bioindicator D. rerio. Herbicides metsulfuron, pyrazosulfuron, bispyribac, bentazon and  quinclorac present low to light risk to the fish D. rerio.Este trabalho teve como objetivo determinar a CL50; 48h de alguns herbicidas e inseticidas utilizados na cultura do arroz irrigado e estimar os coeficientes de risco (análise de risco determinístico), usando como organismo-teste o peixe paulistinha (Danio rerio). Os herbicidas 2,4-D,metsulfurom-metílico, carfentrazona-etílica, bentazona, quincloraque, clomazona, oxadiazona, oxifluorfem, bispiribaque-sódico, pirazossulfurom-etílico apresentaram valores de CL50; 48h em mg.L-1 (ingrediente ativo) de: 237,1; >100,0; 2,5; 1150,0; 300,0; 13,8; 3,9; 1,2; >100,0; 67,56, respectivamente. Os inseticidas betaciflutrina, carbofurano, fipronil e lambdacialotrina apresentaram valores de CL50: 48h em mg.L-1 (ingrediente ativo) de: 0,004; 1,3; 0,2 e 0,002, respectivamente. Os resultados deste trabalho indicaram que os herbicidas oxifluorfem, oxadiazona e clomazona e os inseticidas lambdacialotrina, betaciflutrina, carbofurano e fipronil apresentam maior potencial de risco de impacto ecológico sobre o bioindicador D. rerio. Os herbicidas metsulfurom, pirazossulfuron, bispiribaque, bentazona e quincloraque revelaram risco mínimo a leve de impacto sobre peixes da espécie D. rerio

Macromedusae of Southern Brazil: temporal variation, population structure and biochemical composition

O objetivo do presente estudo foi realizar um levantamento das espécies de macromedusas ocorrentes no Litoral Norte de Santa Catarina, avaliar sua dinâmica populacional e as variações na composição bioquímica, por meio de saídas de campo mensais, ocorridas entre janeiro de 2012 até outubro de 2014. As análises bioquímicas das umbrelas incluiram seu conteúdo em água, carboidratos, proteínas, lipídeos, cinzas, e, destas, sua composição. Foram encontradas seis espécies de macromedusas: Chiropsalmus quadrumanus e Tamoya haplonema (Cubozoa); Olindias sambaquiensis e Rhacostoma atlanticum (Hydrozoa); Chrysaora lactea e Lychnorhiza lucerna (Scyphozoa). As espécies de maior ocorrência e típicas da região foram Olindias sambaquiensis e Rhacostoma atlanticum. Ambas apresentaram alta variabilidade entre os anos, sendo que as maiores densidades foram obtidas entre o outono e o inverno de 2014, associadas a um inverno menos rigoroso e águas mais salgadas. As Cubozoas apresentam maior conteúdo em matéria orgânica, sendo as cinzas ricas em metais. R. atlanticum apresentou sazonalidade na composição química, estando as proteínas relacionadas com o pico reprodutivo da espécie.The objectives of this study were to record the macromedusae species on the north coast of Santa Catarina, and to estimate their population dynamics and variations in their biochemical composition, based on the specimens obtained in the by-catch of artisanal shrimp fishing between January 2012 and October 2014. Cohort analysis was performed to evaluate the population dynamic of the most frequent species. Biochemical analyses of the umbrellas were conducted on their water, carbohydrate, protein, lipid, ash and metals contents. Six species of macromedusae were found: Chiropsalmus quadrumanus and Tamoya haplonema (Cubozoa); Olindias sambaquiensis and Rhacostoma atlanticum (Hydrozoa), and Chrysaora lactea and Lychnorhiza lucerna (Scyphozoa). The species with the highest occurrence, and typical of the region, were Olindias sambaquiensis and Rhacostoma atlanticum. These species showed high inter-year variability, the highest densities being observed between autumn and winter 2014, associated with a less severe winter and coastal water with higher salinity. The distribution of size classes of O. sambaquiensis suggests two well-defined cohorts in spring/summer and in autumn/winter. R. atlanticum showed continuous reproduction and inter-year variation but a high value for protein content related to the reproductive peak in autumn. However, the Cubozoa species showed higher organic matter and metal content than the other classes

Assessment of sea urchin spawning induction and oocyte conservation applied to ecotoxicological assays

Marine toxicity tests using sea urchin embryos and larvae are characterized by physicochemical induction for the release of gametes by adult organisms and by the production of excess gamic material after induction. Evaluating the effects of mortality that inducers cause on organisms, and the improvement in oocyte maintenance techniques for subsequent use, are actions of interest in the conservation of species and the sustainable use of this type of biological model. For this study, adults of the sea urchin species Lytechinus variegatus and Echinometra lucunter were obtained from the field for inductions and tests with their gametes in the laboratory. The species L. variegatus was used in maintenance experiments to assess health after induction (longline outdoor and indoor tanks) and mortality rates after induction by potassium chloride (KCl) and a mixture of potassium chloride with calcium chloride (CaCl2 ), and to evaluate bacterial growth as well as antibiograms of seawater resulting from induced spawning and in vitro fertilization. For the species E. lucunter, experiments with the same chemical inducers on mortality rates were carried out, as well as the conservation of oocytes in artificial seawater with antibiotics selected for their efficiency and toxicity for later use. Maintenance in the laboratory tanks, filled with seawater in a closed system, showed the lowest mortality rates in the group of non-induced organisms (control). The mixture of KCl and CaCl2 resulted in the lowest mortality rates of the adult organisms after spawning induction. The antibiotics Chloramphenicol and Gentamicin showed moderate efficiency in inhibiting bacterial growth, but with low toxicity, demonstrating the ability to maintain the integrity of sea urchin oocytes for up to 14 days under refrigeration

AVALIAÇÃO DA TOXICIDADE AGUDA PARA O ORGANISMO-TESTE Vibrio Fischeri DOS PRINCIPAIS HERBICIDAS E INSETICIDAS APLICADOS NA LAVOURA DE ARROZ IRRIGADO DOS ESTADOS DE SANTA CATARINA E RIO GRANDE DO SUL

Santa Catarina and Rio Grande do Sul are the largest irrigated rice producing states in Brazil, and are highlighted for their intensive use of agricultural chemicals for the control of undesireable competitors and consumers of the crop. In order to evaluate the toxic potential of these agricultural chemicals, and their effects on non-target organisms, this work sought to determine the EC20 and EC50 of the main herbicides and insecticides used in the rice crop, using as a test organism the bioluminescent bacterium Vibrio fischeri. Short duration static tests were carried out (30 minutes), based on the inhibition of luminescence of the bacteria after exposure to the toxic agent. The products tested were the herbicides 2,4-D (DMA 806 BR- dimethylamide), metsulfuron-methyl (Ally), carfentrazone-ethyl (Aurora), bentazon (Basagran), quinclorac (Facet), oxyfluorfen (Goal), bispyribac-sodium (Nominee) and pyrazosulfuron-ethyl (Sírius), and the insecticides betacyflutrin (Bulldock), carbofuran (Furadan), lambdacyhalothrin (Karate) and fipronil (Standak) at maximum concentrations of 100 mg/L (a.i.). The herbicides Ally and Sírius and the insecticides Bulldock and Standak did not present toxicity for the bacterium Vibrio fischeri, as they resulted in an inhibitory effect of less than 20 %. Basagram, Facet, Nominee and Furadam presented toxicity with a EC20 (a.i.) of 40.87 mg/L, 36.00 mg/L, 45.83 mg/L and 3.23 mg/L, respectively, and for the products 2.4-D, Aurora, Goal and Karate, the EC50 values for the active ingredient obtained were 13.90 mg/L, 1.02 mg/L, 19.23 mg/L and 10 mg/L, respectively. Compared with studied carried out with other test organisms, the bacterium V. fischeri and the bioluminescence test presented low sensitivity to the toxicity of the agricultural chemicals.Santa Catarina e Rio Grande do Sul são os maiores produtores de arroz irrigado do Brasil e destacam-se pelo uso intenso de pesticidas para o controle de competidores e consumidores indesejáveis. A fim de avaliar o potencial tóxico desses agroquímicos e seus efeitos sobre organismos não-alvo, o presente trabalho teve como objetivo determinar a CE20 e a CE50 dos principais herbicidas e inseticidas empregados na lavoura do arroz, utilizando como organismo-teste a bactéria bioluminescente Vibrio fischeri. Foram realizados testes estáticos de curta duração (30 minutos), baseados na inibição da luminescência das bactérias após exposição ao agente tóxico. Os produtos testados foram os herbicidas 2,4-D (DMA 806 BR- dimetilamida), metsulfurom metílico (Ally), carfentrazona-etílica (Aurora), bentazona (Basagran), quincloraque (Facet), oxifluorfem (Goal), bispiribaque-sódico (Nominee) e pirazossulfuron etílico (Sírius), e os inseticidas betaciflutrim (bulldock), carbofuran (Furadan), lambdacialotrina (Karate) e fipronil (Standak) em concentrações máximas de 100 mg/L (i.a.). Os herbicidas Ally e Sírius e os inseticidas Bulldock e Standak não apresentaram toxicidade para a bactéria Vibrio fischeri, pois resultaram em efeito inibitório inferior a 20%. Basagram, Facet, Nominee e Furadam apresentaram toxicidade, com valores de CE20 (i.a.) de 40,87 mg/L, 36 mg/L, 45,83 mg/L e 3,23 mg/L, respectivamente. Para os produtos 2,4-D, Aurora, Goal e Karatê, os valores de CE50 dos ingredientes ativos foram 13,90 mg/L, 1,02 mg/L, 19,23 mg/L e 10 mg/L, respectivamente. Em comparação com estudos realizados com outros organismos-teste, a bactéria V. fischeri e o teste de bioluminescência apresentaram baixa sensibilidade frente à toxicidade dos agroquímicos