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Environmental impact studies of rivers affected by wastewater treatment plant (WWTP) effluents have been greatly restricted by the difficulties associated with carrying out bioassays in the field and also by the complex interactions between the pollutants contained in the discharges. The cotton-strip assay (CSA) enables study of the organic matter decomposition potential, an important ecosystem process in rivers, by taking all of the factors affecting this process into account. However, the CSA has never been used for assessment of WWTP effluents. In the present study, we selected six fluvial zones affected by discharges from small WWTPs and placed cotton strips at increasing distances from the discharge points in each zone. After 17 days, we evaluated decay of the strips by measuring cotton tensile strength loss (CTSL) and cotton mass loss (CML). We then determined the relationships between these parameters and various physico-chemical and biological properties in the water, as well as the δ15N isotopic signal and metal contents of aquatic mosses transplanted in the same sampling sites and used as biomonitors. Although the WWTPs were similar, some of the discharges stimulated and others inhibited decomposition of the cotton strips. This was probably due to differences in the proportions of various types of pollutants (with trophic or toxic effects) in the discharges. The CSA proved to be a simple, practical and economic bioassay and suitable for evaluating the ecological integrity of fluvial ecosystems.

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RESUMO A Bacia Hidrográfica Lagos São João (BHLSJ), no Estado do Rio de Janeiro, é reconhecidamente de grande importância para a conservação de recursos naturais e hídricos. No entanto, apesar dos constantes esforços de conservação e recuperação dos ecossistemas aquáticos, as ameaças e os desafios de gestão são diversos. A gestão dos recursos hídricos em bacias hidrográficas requer processos de tomada de decisão assertivos, para garantir a conservação das águas (em quantidade e qualidade) e os seus múltiplos usos. Para maior efetividade, esses processos demandam análise integrada de um grande número de variáveis que, em conjunto, podem gerar diferentes alternativas de gestão e cenários, facilitando, assim, a tomada de decisão. Nesse sentido, ferramentas de análise que possam identificar, quantificar e espacializar as ameaças efetivas à integridade ecológica dos ecossistemas aquáticos em bacias hidrográficas tornam-se relevantes. O presente artigo teve por objetivo apresentar o desenvolvimento e os resultados do diagnóstico da BHLSJ, gerado por meio de um protocolo baseado no risco à integridade ecológica. Como resultado da aplicação dessa metodologia, pode-se concluir que a BHLSJ se encontra em situação de moderado a alto risco ecológico - sendo ameaçada, principalmente, por fatores como a retificação dos rios e as pastagens degradadas - e necessita de ações urgentes de recuperação, com foco nas unidades hidrológicas mais ameaçadas.

ABSTRACT Lagos São João River Basin, located in Rio de Janeiro state, Brazil, is known of great importance for the conservation of natural and water resources. However, despite constant efforts to conserve and restore the aquatic ecosystems, many are the threats and management challenges. The water resources management in river basins requires assertive decision-making processes to ensure the conservation of water quantity and quality and its multiple uses. Aiming to be more effective, these processes require an integrated analysis of a large number of variables, which together can lead to different management alternatives and scenarios, thereby facilitating decision-making. In this sense, analytical tools that can identify, quantify and spacialize the current threats to the ecological integrity of aquatic ecosystems become relevant. This article aimed to present the development and results of the diagnosis of Lagos São João River Basin, generated through a risk-based protocol to ecological integrity. As a result of the application of this methodology, it can be concluded that Lagos São João River Basin is in a situation of moderate to high ecological risk, being threaten by river engineering and degraded grassland, demanding urgent restoration actions, focusing on the most endangered hydrologic units.

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Abstract Atypical drought events have increasingly occurred in Brazil over the last years due to global climate changes. However, their consequences on aquatic biota in reservoirs are poorly known. We tested the hypothesis that macroinvertebrate communities are negatively affected by atypical drought events, given the sensitivity of many taxa to environmental changes. We predicted that: (a) there would be changes in limnological and sediment parameters between a regular year and an atypical year, (b) abundance and richness of the genera of Chironomidae and of exotic species would be higher due to the enhanced ability of these organisms to adapt to changes in the physical environment, and (c) community structure metrics (i. richness; ii. % richness; iii. abundance; iv. % abundance) would be affected by disturbance indices (i. Buffer Disturbance Index-BDI; ii. Local Disturbance Index-LDI; iii. Integrated Disturbance Index-IDI) in both years. The study was carried out in the reservoir of the Nova Ponte Hydroelectric Power Plant, state of Minas Gerais, comparing two sampling periods: a regular climatological year (2010) and an atypical drought year (2014). A total of 40 sampling sites were defined along the shore of the reservoir, and types of land use in the surrounding area of each site were measured, as well as physical habitat conditions, sediments, and benthic macroinvertebrate communities. Sampling was performed at these sites in the end of the rainy season in both years. The intensity of anthropogenic modifications was assessed at local scale and in the areas (buffers) surrounding the sampling sites using quantitative disturbance indices. There were striking differences in limnological parameters and sediment characteristics between sampling periods. Taxonomic richness was significantly lower in the drought year. As opposed to our predictions, richness and abundance of Chironomidae and exotic species did not increase with the atypical drought event. Besides, most community structure metrics showed a significant relationship with disturbance indices only during the regular climatological year, thus indicating that the large-scale effects of water stress may override the conditions of local habitats and the surrounding landscape. Therefore, in addition to a correct political-environmental management of water resources at local-scale, which includes maintaining the water quality and the riparian and landscape integrity, addressing large-scale climate issues is required for the maintenance of the ecological integrity of tropical reservoirs.

Resumo A ocorrência de episódios atípicos de seca vem crescendo nos últimos anos no Brasil em decorrência de mudanças globais no clima. Entretanto, as consequências disso para a biota aquática são ainda pouco conhecidas. Testamos a hipótese de que comunidades de macroinvertebrados são negativamente afetadas por eventos de seca atípica, dada a sensibilidade de muitos taxa às alterações ambientais. Nossas predições foram que (a) parâmetros limnológicos e características de sedimento seriam alterados em um ano de seca atípica, (b) encontraríamos maior abundância e riqueza de gêneros de Chironomidae e de espécies exóticas dada à alta capacidade destes organismos de adaptarem-se às mudanças no ambiente, (c) métricas de estrutura de comunidade (i. riqueza; ii. % riqueza; iii. abundância e iv. % abundância) seriam afetadas por índices de distúrbio (i. Índice de Distúrbio no Buffer-IDB; ii. Índice de Distúrbio Local-IDL e iii. Índice de Distúrbio Integrado-IDI) em ambos os anos. O estudo foi realizado no reservatório da Usina Hidrelétrica de Nova Ponte, Minas Gerais, comparando dois períodos amostrais: um ano climatológico normal (2010) e um ano de seca atípica (2014). Foram definidos 40 sítios amostrais na região litorânea do reservatório onde foram mensurados os tipos de usos do solo no entorno, condições de habitats físicos, características limnológicas na coluna d'água, sedimento e comunidades de macroinvertebrados bentônicos. A intensidade de alterações antrópicas foi avaliada em escala local e no entorno dos pontos amostrais (buffers) por meio de índices de distúrbio. Observamos diferenças expressivas nos parâmetros limnológicos e nas características dos sedimentos entre os dois períodos amostrais. A riqueza taxonômica foi significativamente menor no ano de seca. Ao contrário do esperado, os valores de riqueza e abundância de Chironomidae e de espécies exóticas não aumentaram com o evento extremo de seca. Paralelamente, a maioria das métricas de estrutura de comunidade apresentou relação significativa com os índices de distúrbio somente durante o ano climatológico normal, indicando que os efeitos de estresse hídrico em larga escala podem se sobrepor às condições locais de habitat e de paisagem circundante. Portanto, deve ser considerada não só a correta gestão político-ambiental de recursos hídricos em escala local, que inclui a manutenção da qualidade da água e da integridade da região ripária e uso do solo da região de entorno, mas também abordar questões climáticas em larga escala faz-se necessário para a manutenção da integridade ecológica em reservatórios tropicais.

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Gorgona, located in the southern zone of the Pacific Ocean of Colombia, is an insular territory at 35km in a straight line from the continental margin. Although historically this island was used in different forms, since 1984 it has been among the most important protected marine areas of the Colombian Pacific Ocean. Here we review the historical development of scientific research in Gorgona island and its importance for marine and coastal conservation in the Colombian Pacific region. The island is an strategic location for the Eastern Tropical Pacific Conservation Corridor. Its ecological status is acceptable but the populations of Bradypus variegatus and Proechymis simispinosus are too small and monitoring and scientific programs need to continue. Rev. Biol. Trop. 62 (Suppl. 1): 1-12. Epub 2014 February 01.

La Gorgona, ubicada en el sector sur del Pacífico Colombiano, es un territorio insular que se encuentra a 35km en línea recta del margen continental. Aunque históricamente tuvo diferentes usos, desde 1984 conforma una de las áreas marinas protegidas más importantes del Pacífico Colombiano. Aquí se presenta la recopilación histórica del desarrollo de la investigación científica en isla Gorgona, localidad clave para los programas de conservación marino-costeros del Pacífico Colombiano y el corredor marino de conservación del Pacífico Oriental Tropical. La integridad ecológica del PNN Gorgona es aceptable pero deben mejorarse los indicadores asociados a las poblaciones de Bradypus variegatus y Proechymis simispinosus, ya que tienen un riesgo muy elevado de desaparición. Es fundamental continuar recopilando la información técnica necesaria para ajustar los estimadores de estado de conservación.

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Insects have been recognized to be important indicators of the quality elements of ecosystems, among others, because of their rapid response to environmental variability and ease cost-effective capture. In this work we evaluated whether beetles of the Scarabaeoidea superfamily may be used as bioindicators of anthropogenic disturbance of Amazonian terra firme rain forests, in order to provide guidelines for monitoring strategies of the Amacayacu National Park. We considered three different levels of anthropogenic disturbance (i.e. low, medium, high) in 12 transects (four in each intervention level), and caught all beetle species of this superfamily. Three interception traps, two light traps, three pitfalls and four bottle fruit traps were used per transect, as well as manual catch. In total, 593 individuals belonging to 92 species, 44 genera and seven families were collected. Scarabaeidae (n=232, 27 spp.) and Dynastidae (n=161, 26 spp.) were the families with the highest number of individuals and species, while Aphodiidae, Cetoniidae and Geotrupidae exhibited the lowest. The most abundant species per family were Ateuchus sp. (33.2%) from Scarabaeidae, Cyclocephala verticalis (55.9%) from Dynastidae, Astaena sp. (75.8%) from Melolonthidae, Ceratocanthus amazonicus (66.7%) from Ceratocanthidae y Chaetodus asuai (96.8%) from Hybosoridae. Results showed that the number of species and individuals increased with the anthropogenic disturbance. The Margalef and Shannon indexes also revealed that the highest richness and equity occurred in the high-disturbed site, respectively. Dynastidae exhibited the highest number of exclusive species per gradient, while Scarabaeidae shared most of its species. Ten species were recorded in the three disturbance levels, 26 species in two and 56 species were exclusive to one level. The most abundant species Chaetodus asuai (Hybosoridae) presented a significant decrease in the number of individuals as disturbance increased, while an inverse relationship occurred for C. verticalis(Dynastidae). For Astaena sp. (Melolonthidae) and Ligyrus gyas (Dynastidae) a high number of individuals was recorded and were exclusive for one forest site (low and high disturbed forest, respectively). The complete superfamily cannot be used like a single bioindicator element because it displays, in a specific level, very different behaviors in each disturbance condition. We discuss the use of richness and diversity as indicators of disturbance, while we highlight abundance of particular taxa as a better metric for disturbance.

Diferentes grupos de insectos se consideran importantes elementos bioindicadores de la calidad de los ecosistemas, los coleópteros son hoy en día uno de los grupos más reconocidos y utilizados para el monitoreo y establecimiento de áreas protegidas. Se evaluó el uso de la superfamilia Scarabaeoidea como bioindicador del grado de perturbación antropogénica de los bosques húmedos amazónicos. En tres niveles de perturbación (alta, media y baja) se establecieron 12 transectos, utilizando tres trampas de interceptación, dos trampas de luz, tres trampas de caída, cuatro trampas de botella y captura manual. Se capturaron 593 individuos, 92 especies, 44 géneros y 7 familias. Las familias con el mayor número de individuos y especies fueron Scarabaeidae (n=232, 27 spp.) y Dynastidae (n=161, 26 spp.). Las especies más abundantes fueron: Ateuchus sp., Cyclocephala verticalis, Ceratocanthus amazonicus y Chaetodus asuai. El número de especies e individuos fue mayor a medida que el gradiente de perturbación aumentó. Dynastidae presenta el mayor número de especies exclusivas mientras Scarabaeidae comparte la mayoría. Diez especies fueron registradas en los tres bosques, 26 en dos y 56 en solo uno. De las especies más abundantes C. asuai muestra una reducción significativa del número de individuos con el aumento de la perturbación, mientras se observa una relación inversa para C. verticalis. Se discute la utilización de la riqueza y la diversidad como indicadores de perturbación, mientras se ratifica la abundancia de ciertos táxones como una mejor variable a medir.

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