Abstract This study investigated injuries sustained by Pimelodus maculatus caused by transient operating conditions in a Brazilian hydroelectric power plant. Fish (n = 43) that inhabited the tailrace and appeared on the water surface after changes in the operating conditions were evaluated (IF). Additionally, fish (n = 10) captured using longline in the vicinity of the tailrace were used for comparisons (NF). Blood samples were evaluated for cortisol, glucose, and lactate concentrations. Tissue samples (gill, liver, brain, and muscle) were analyzed for oxidative stress biomarkers (TBARS, protein carbonyl content, and catalase activity) and histology (gill, liver, and spleen). The most prominent findings in IF were barotraumas with intra-abdominal hemorrhage and swim bladder rupture. Cortisol and glucose concentrations were lower for IF when compared to NF. IF also suffered from oxidative stress, as indicated by increased TBARS in the liver and brain, as well as increased protein carbonyl content in the gills and liver. The main histological alterations induced by the adverse conditions were circulatory disorders, such as telangiectasia and gill aneurysm, hepatic congested veins, and hemorrhage in the liver and spleen. The abrupt drop of pressure resulting from changes in the operating conditions of the turbines caused barotraumas and oxidative stress, which were the leading causes of fish mortality

Resumo Este estudo investigou os efeitos induzidos por condições transitórias de operação em uma usina hidrelétrica brasileira em Pimelodus maculatus. Peixes (n = 43) no canal de fuga que apareceram na superfície da água após mudanças nas condições operacionais foram avaliados. Adicionalmente, peixes (n = 10) capturados a jusante da barragem com espinhel foram utilizados para comparações (NF). Amostras de sangue foram avaliadas para as concentrações de cortisol, glicose e lactato. Amostras de tecidos (brânquia, fígado, cérebro e músculo) foram analisadas para biomarcadores de estresse oxidativo (TBARS, conteúdo de proteína carbonil e atividade da catalase) e histologia (brânquia, fígado e baço). Os achados mais proeminentes dos peixes afetados (IF) foram barotraumas com hemorragia intra-abdominal e ruptura da bexiga natatória. As concentrações de cortisol e glicose foram menores para IF quando comparadas aos NF. IF também sofreram estresse oxidativo representado pelo aumento de TBARS no fígado e cérebro, e aumento do conteúdo das proteínas carboniladas nas brânquias e fígado. As principais alterações histológicas induzidas pelas condições adversas foram distúrbios circulatórios, como telangiectasia e aneurisma nas brânquias, congestão das veias hepáticas, e hemorragia no fígado e baço. A queda abrupta da pressão resultante de mudanças nas condições operacionais das turbinas causou barotrauma e estresse oxidativo, que foram as principais causas da mortalidade dos peixes.

Abstract It is estimated that infections caused by bacteria of to the genus Vibrio are sub notified, however it is possible to notice the increase in the vibriosis incidence associated to the consumption of contaminated water and food, specially by raw seafood. Vibrio cholerae, Vibrio parahaemolyticus e Vibrio vulnificus are the main pathogenic species for humans and the infections caused by these bacteria can range from simple gastroenteritis to cases of sepsis. In Brazil, until 2020, the legislation that determined the microbial standards for food, RDC 12/2001, recommended that the presence of V. parahaemolyticus should be investigated in ready-to-eat food based on raw fish and similar. However, IN60, the new legislation that came into force on December 2020, no longer requires it. Since the presence of these bacteria are important risk factors for humans, as agents of diseases transmitted specially by food, it is important to monitor their presence in foods of marine origin, especially in fish and shellfish that will be consumed raw. Therefore, preventive approaches are needed, such as the control and monitoring of microbiological quality of water, mainly in high-risk food production environments (such as oysters, for example) and the microbiological control of these foods, including vibrio research.

Abstract Algal polysaccharides exhibit a wide range of biological activities and potential applications. Many of these bioactivities correlate positively with the presence of sulfate groups on the polysaccharides. The most common method used for sulfate quantification in algal samples is the turbidimetric method using the barium chloride-gelatin reagent. However, the original procedure is difficult to adapt for routine analysis since it is laborious and time-consuming. An optimized method was established using 96-well microplates, with the advantage of reducing waste and discrimination between organic and inorganic sulfates. This proposed method produced the same accuracy as the original.

Este estudo objetivou avaliar o efeito da adição de doses crescentes de dejetos de suínos, adubação organomineral e adubação mineral sobre a abundância e diversidade da macrofauna edáfica. O estudo foi realizado no município de Campos Novos, SC, em um Latossolo Vermelho distroférrico, cultivado anualmente com milho (Zea mays) e aveia (Avena sativa), em sucessão e semeadura direta. Os seis tratamentos utilizados foram: testemunha (TT); adubação mineral (AM); adubação organomineral (AOM); adubação orgânica na doses de 3 t ha-1 (AO3); 6 t ha-1 (AO6) e 12 t ha-1 (AO12) de dejeto de suínos em base seca. O fertilizante mineral foi aplicado em semeadura na linha do plantio e a adubação orgânica, após semeadura do milho. A macrofauna edáfica foi avaliada utilizando-se um amostrador cilíndrico com 17 cm de diâmetro, coletando-se amostras de solo na profundidade de 0-10 cm. As amostragens foram realizadas em três épocas: a primeira em 5/5/2005 (um mês após a colheita do milho), a segunda em 9/09/2005 (sob a cultura de aveia), e a terceira em 23/1/2006 (sob a cultura do milho). A diversidade de organismos foi avaliada por meio dos índices de Shannon, Simpson e Pielou, riqueza de grupos, abundância e análise de agrupamento. A freqüência relativa das ordens foi afetada pela adição do dejeto suíno, sendo os grupos mais freqüentes Hymenoptera e Oligochaeta, variando conforme o tratamento e a época de amostragem. A maior diversidade da macrofauna foi encontrada no tratamento AOM, demonstrando que a macrofauna edáfica foi influenciada pela adição consorciada das diferentes formas de adubação.

The present study aimed to evaluate the effect of addition of increasing rates of swine manure, mineral fertilizers, and the combination of both on the abundance and diversity of soil macrofauna. The study was carried out in Campos Novos county, in the western Santa Catarina state, on an Oxisol cultivated with corn (Zea mays) and oat (Avena sativa) in succession and no tillage system. Six treatments were used: a control, with no fertilization (TT); mineral fertilization (AM); swine manure + mineral fertilizer (AOM); and swine manure at dry matter rates of 3 t ha-1 (AO3); 6 t ha-1 (AO6) and 12 t ha-1 (AO12). Mineral fertilizer was applied in-furrow, at sowing, and swine manure just after corn sowing. The soil macrofauna was evaluated with a cylinder of 17 cm diameter. Three samplings in the top layer 0-10 cm were carried out: the first in 5/5/2005 (one month after corn harvest), the second in 9/09/2005 (under oat) and the third in 23/1/2006 (under corn). The diversity of organism groups was evaluated by the Shannon, Simpson and Pielou indexes, group richness, abundance and cluster analysis. The relative frequency of the orders was affected by swine manure addition. Hymenoptera and Oligochaeta were the most frequent groups and they varied according to the treatment and sampling time. The greatest diversity in macrofauna was found under the AOM treatment, demonstrating that the soil macrofauna was affected by fertilization.