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This study investigated the fish fauna of a stream in southeastern Brazil that runs through sugar cane-growing and urban areas that are subject to sewage discharge. It aimed to determine the importance of spatial and environmental factors on fish distributions and to assess the use of fish as indicators of the environmental conditions. A longitudinal pattern of chemical water quality was observed, with more disturbed conditions at the urban sites. Several opportunistic or tolerant and omnivorous species such as Astyanax altiparanae, Poecilia reticulata, and Astyanax fasciatus were numerically abundant at these urban sites, which resulted in a consistent increase in species density and biomass along the stream. Redundancy analysis extracted three axes, identifying a nutrient-productivity gradient associated with different species composition patterns, as also detected by the indicator species analysis. No species could be considered a potential indicator of the agricultural area in the dry season, whereas four different species were judged potential indicators of three urban sites. In order to explain species distribution, variation in species abundance was partitioned into spatial and environmental components. The latter was more important, explaining 25.4% of the variation. We concluded that the fish assemblage of the Guamium stream is undergoing the initial stages of disturbance, with pronounced effects at the urbanized area, but no detectable changes at the sugar cane sites. Therefore, fish assemblages might be used as ecological indicators to detect urban impacts in similar rivers. However, the potential use of fish to diagnose stressors in areas of sugar cane plantations should be complementary to more comprehensive studies aimed at understanding the influence of this crop on freshwater resources.

-A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.Keywords: glyphosate, green chemistry, herbicide, HPLC.RESUMO -Um método melhor para a determinação do chiquimato em tecidos de plantas é necessário para monitorar a exposição destas ao herbicida glyphosate N-(fosfonometil)glicina] e selecionar o gênero da planta para altos níveis desse valioso precursor fitoquímico ao fármaco oseltamivir. Um método simples, rápido e eficiente, que usa a extração assistida por micro-ondas (MWAE) com água como solvente de extração, foi desenvolvido para a determinação do ácido chiquímico em tecidos de plantas. Foi empregada cromatografia líquida de alto desempenho para a separação do ácido chiquímico, e os dados cromatográficos foram obtidos utilizando arranjo de fotodiodo. Essa técnica de MWAE obteve sucesso na recuperação do ácido chiquímico de uma série de tecidos de planta fortificados, com mais de 90% de eficiência e um cromatograma livre de interferências. Isso permitiu a utilização de menores quantidades de reagentes e de solventes orgânicos, reduzindo o uso de produtos químicos tóxicos e/ou perigosos, em comparação às metodologias atualmente empregadas. O método foi usado para determinar o nível de ácido chiquímico endógeno em diversas espécies d e Brachiaria e de cana-de-açúcar (Saccharum officinarum), em B. decumbens e na soja (Glycine max) após o tratamento com glyphosate. O método foi sensível, rápido e confiável em todos os casos.Palavras-chave: glyphosate, química verde, herbicida, HPLC.

The practice of intensive herbicide use in the sugarcane industry has a high risk of compromising the quality of the water and the organisms that live there due to losses through runoff, leaching and other processes. In this work, the dynamics of four herbicides present in three different mixtures were evaluated through their incorporation and elimination in the muscle tissue of tilapia ( Oreochromis niloticus ). The highest mean values of bioconcentration factors were 1.730 for ametryn, 0.891 for tebuthiuron, 0.322 for hexazinone and 4.783 for diuron. Diuron presented the highest risk regarding the consumption of tilapia fillets by the population. However, considering that the fish would reach maximum levels of diuron when exposed to extremely high concentrations, an individual weighing 70 kg would need to ingest approximately 1.5 kg of this food product to surpass the acceptable daily intake of 0.007 mg kg −1 body weight. It was concluded that the risk of injury to the population consuming tilapia fillets from fish exposed to herbicides in water arising from sugarcane activities is very low. According to the risk estimation performed in this work, which is substantiated by the assumptions of the World Health Organization and the International Life Sciences Institute, there is a low risk of injury to the population consuming tilapia fillets from fish exposed to water containing herbicides in concentrations arising from sugarcane activities. However, as the risk was estimated from laboratory conditions, caution should be taken where herbicide applications are carried out with high frequency near water bodies, as the consumption of fish from these areas is quite common.

Ametryn (AMT) is one of the most widely used herbicides in tropical sugarcane crops, the main culture of São Paulo State, Brazil. It is known as a diffuse pollutant, being found in surface water and sediment of water bodies adjacent to the crop fields. In the present study, the toxicity of AMT to zebrafish (Danio rerio) embryos was evaluated using developmental and biochemical endpoints. At the biochemical level, lactate dehydrogenase responded at the lowest concentration tested (4 μg L) indicating a high demand of energy required to cope with the stress condition. Antioxidant enzyme levels were changed at intermediate/high concentrations while oxidative damage (lipid peroxidation) was observed at the last concentration tested (10 mg L). This suggests that, like for other herbicides from the triazine group, oxidative stress is a major pathway of toxicity for AMT. Several developmental effects such as oedemas and tail deformities were also observed. The 96 h-EC values calculated for different developmental parameters were between 17 and 29 mg L. AMT also affected hatching (96 h-EC = 22.5 mg L) and positioning in the water column (96 h-EC = 13.2 mg L). In a previous work of the group, lethal toxicity of AMT showed to be much higher to adults than to embryos. However, in the present work, sublethal endpoints assessed suggest that important effects are observed at lower concentrations, improving the sensitivity of the embryo test. Moreover, in this work, sublethal effects were observed for concentrations in the same range as the ones found in the environment, and thus, given that this chemical is widely used in tropical fields, a refined evaluation of risk should be performed based on the monitoring of sublethal and long-term parameters and considering mixture scenarios.