Progress in the environmental risk assessment of plant protection products in Brazil: An overview of aquatic organism proposals.

Since 2019, the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA) has actively developed pesticide environmental risk assessment (ERA) frameworks adapted to Brazil's specific ecological contexts. This endeavor, supported by funding from the Brazilian Ministry of Justice and in partnership with academic institutions, has led to a concerted effort to establish ERA protocols for various taxa, including birds and mammals, soil organisms, aquatic organisms, and reptiles and amphibians. The outcomes of this initiative were conveyed in two workshops held in February and November 2023, during which the agency communicated its findings to the technical-regulatory community. This article represents one of two articles that provide more detailed insights into the ERA propositions for all taxa. In this article, we summarize the proposals for aquatic organisms presented and discussed during the workshops, which can be used as an informational source by the technical-regulatory community. Integr Environ Assess Manag 2024;20:1787-1792. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Invertebrate dispersal by waterbird species in neotropical wetlands / A dispersão de invertebrados por aves aquáticas na região neotropical

Abstract Endozoochory by waterbirds is particularly relevant to the dispersal of non-flying aquatic invertebrates. This ecological function exercised by birds has been demonstrated in different biogeographical regions, but there are no studies for the neotropical region. In this work, we identified propagules of invertebrates in faeces of 14 syntopic South American waterbird species representing six families, and hatched additional invertebrates from cultured faeces. We tested whether propagule abundance, species richness and composition varied among bird species, and between the cold and warm seasons. We found 164 invertebrate propagules in faecal samples from seven different waterbirds species, including eggs of the Temnocephalida and Notonectidae, statoblasts of bryozoans (Plumatella sp.) and ephippia of Cladocera. Ciliates (including Paramecium sp. and Litostomatea), nematodes and rotifers (Adineta sp. and Nottomatidae) hatched from cultured samples. Potential for endozoochory was confirmed for 12 of 14 waterbird species. Our statistical models suggest that richness and abundance of propagules are associated with bird species and not affected by seasonality. Dispersal by endozoochory is potentially important to a broad variety of invertebrates, being promoted by waterbirds with different ecological and morphological traits, which are likely to drive the dispersal of invertebrates in neotropical wetlands.

Resumo A endozoocoria promovida por aves aquáticas é particularmente relevante para a dispersão de invertebrados aquáticos não-voadores. Essa função ecológica exercida pelas aves tem sido demonstrada para diferentes regiões biogeográficas, porém, não existem estudos para a região neotropical. Neste trabalho nós identificamos propágulos de invertebrados encontrados em fezes de 14 espécies sintópicas de aves aquáticas da América do Sul, representando seis famílias de aves, e também invertebrados emergidos de amostras fecais cultivadas em laboratório. Testamos se a abundância, riqueza de espécies e composição de propágulos de invertebrados variavam entre as espécies de aves e entre estações. Nós encontramos 164 propágulos de invertebrados em amostras fecais de sete espécies de aves, incluindo ovos de Temnocephalida e Notonectidae, estatoblastos de briozoários (Plumatella sp.) e efípios de Cladocera. Ciliados (incluindo Paramecium sp. e Litostomatea), nematóides e rotíferos (Adineta sp. e Nottomatidae) eclodiram de amostras cultivadas. O potencial para endozoocoria foi confirmado para 12 das 14 espécies de aves aquáticas investigadas. Nossos modelos estatísticos sugerem que a riqueza e abundância de propágulos estão associadas às espécies de aves e não são afetadas pela sazonalidade. A dispersão por endozoocoria é importante para uma ampla variedade de invertebrados, sendo promovida por aves aquáticas com diferentes características ecológicas e morfológicas as quais provavelmente regulam a dispersão de invertebrados entre áreas úmidas neotropicais.

Invertebrate dispersal by waterbird species in neotropical wetlands

Abstract Endozoochory by waterbirds is particularly relevant to the dispersal of non-flying aquatic invertebrates. This ecological function exercised by birds has been demonstrated in different biogeographical regions, but there are no studies for the neotropical region. In this work, we identified propagules of invertebrates in faeces of 14 syntopic South American waterbird species representing six families, and hatched additional invertebrates from cultured faeces. We tested whether propagule abundance, species richness and composition varied among bird species, and between the cold and warm seasons. We found 164 invertebrate propagules in faecal samples from seven different waterbirds species, including eggs of the Temnocephalida and Notonectidae, statoblasts of bryozoans (Plumatella sp.) and ephippia of Cladocera. Ciliates (including Paramecium sp. and Litostomatea), nematodes and rotifers (Adineta sp. and Nottomatidae) hatched from cultured samples. Potential for endozoochory was confirmed for 12 of 14 waterbird species. Our statistical models suggest that richness and abundance of propagules are associated with bird species and not affected by seasonality. Dispersal by endozoochory is potentially important to a broad variety of invertebrates, being promoted by waterbirds with different ecological and morphological traits, which are likely to drive the dispersal of invertebrates in neotropical wetlands.

Resumo A endozoocoria promovida por aves aquáticas é particularmente relevante para a dispersão de invertebrados aquáticos não-voadores. Essa função ecológica exercida pelas aves tem sido demonstrada para diferentes regiões biogeográficas, porém, não existem estudos para a região neotropical. Neste trabalho nós identificamos propágulos de invertebrados encontrados em fezes de 14 espécies sintópicas de aves aquáticas da América do Sul, representando seis famílias de aves, e também invertebrados emergidos de amostras fecais cultivadas em laboratório. Testamos se a abundância, riqueza de espécies e composição de propágulos de invertebrados variavam entre as espécies de aves e entre estações. Nós encontramos 164 propágulos de invertebrados em amostras fecais de sete espécies de aves, incluindo ovos de Temnocephalida e Notonectidae, estatoblastos de briozoários (Plumatella sp.) e efípios de Cladocera. Ciliados (incluindo Paramecium sp. e Litostomatea), nematóides e rotíferos (Adineta sp. e Nottomatidae) eclodiram de amostras cultivadas. O potencial para endozoocoria foi confirmado para 12 das 14 espécies de aves aquáticas investigadas. Nossos modelos estatísticos sugerem que a riqueza e abundância de propágulos estão associadas às espécies de aves e não são afetadas pela sazonalidade. A dispersão por endozoocoria é importante para uma ampla variedade de invertebrados, sendo promovida por aves aquáticas com diferentes características ecológicas e morfológicas as quais provavelmente regulam a dispersão de invertebrados entre áreas úmidas neotropicais.

Food preference of Phylloicus sp. (Insecta: Trichoptera): experimental study with plant species from the Cerrado / Preferência alimentar de Phylloicus sp. (Insecta: Trichoptera): trabalho experimental com espécies vegetais do Cerrado

Abstract The aquatic insects of the genus Phylloicus play a crucial role in aquatic ecosystems, shredding leaves and contributing to nutrient cycling in streams. Therefore, this genus is often used in laboratory experiments. However, in Cerrado regions such as Araguaia, these studies are impractical due to a lack of knowledge about basic aspects, such as their feeding preferences for local plants. Hence, our objective is to determine the native plant species in the Araguaia region preferred as food by Phylloicus. We conducted an experimental study comparing the consumption of three native Cerrado plant species: Casearia sylvestris, Astronium fraxinifolium, and Ficus guaranítica by Phylloicus. To assess differences in consumption, we performed an Analysis of Variance. The results revealed that Phylloicus larvae exhibited a feeding preference for Casearia sylvestris (F = 9.71; p = 0.004). This finding will contribute to the development of future experimental studies using Phylloicus in the Araguaia region, as understanding the feeding preferences of animals used in experiments is essential for their maintenance in the laboratory.

Resumo Os insetos aquáticos do gênero Phylloicus desempenham um papel essencial nos ecossistemas aquáticos, fragmentando folhas e contribuindo para a ciclagem de nutrientes nos riachos. Por isso, esse gênero é frequentemente utilizado em experimentos de laboratório. No entanto, em regiões de Cerrado como o Araguaia, esses trabalhos são inviáveis por não se conhecer aspectos básicos como a sua preferência alimentar por plantas locais. Por isso, nosso objetivo é responder quais são as espécies vegetais nativas da região do Araguaia preferidas para a alimentação de Phylloicus. Fizemos um trabalho experimental comparando o consumo de três espécies vegetais nativas do Cerrado: Casearia sylvestris, Astronium fraxinifolium e Ficus guaranítica pelos Phylloicus. Para avaliar as diferenças no consumo, realizamos uma Análise de Variância. Os resultados obtidos revelaram que as larvas de Phylloicus demonstraram preferência alimentar por Casearia sylvestris (F = 9.71; p = 0.004). Esse achado ajudará no desenvolvimento de futuros trabalhos experimentais utilizando Phylloicus na região do Araguaia, uma vez que é essencial o conhecimento da preferência alimentar dos animais utilizados nos experimentos para sua manutenção em laboratório.

Diversity of aquatic macroinvertebrates and habitat quality in tributaries of the national natural park Selva Florencia / Diversidad de macroinvertebrados acuáticos y calidad de hábitat en afluentes del parque nacional natural selva florencia

RESUMEN Los ecosistemas de agua dulce son una fuente primaria de servicios ecosistémicos esenciales para sustentar la vida y albergan una importante diversidad de especies acuáticas. El conocimiento sobre los macroinvertebrados acuáticos es precario en áreas declaradas como protegidas de Colombia. Este estudio tuvo como objetivo evaluar la diversidad de macroinvertebrados acuáticos bioindicadores y la calidad ecológica de hábitat del Parque Nacional Natural Selva de Florencia (PNNSF). Se recolectaron muestras de macroinvertebrados en seis microcuencas, cuatro ubicadas dentro del Parque y dos en la zona de amortiguamiento. Se realizaron análisis de diversidad de orden Q, variación en la composición de especies, y su relación con las variables fisicoquímicas. Para estimar la calidad del hábitat y del agua se aplicaron los siguientes índices: Índice de Integridad del Hábitat (IIH), Índice de Calidad del Ecosistema Ribereño (QBR), y el BMWP. Se recolectaron un total de 2894 macroinvertebrados acuáticos. Los órdenes más representativos fueron Ephemeroptera y Trichoptera. Los resultados del IIH fueron de moderada a alta integridad. El QBR fluctuó entre 65-100, indicando un nivel de calidad intermedia, buena y muy buena. El BMWP indicó que todos los afluentes estudiados se encuentran en la categoría de aguas muy limpias sin evidencias de contaminación. Finalmente, se concluye que el PNNSF y su zona de amortiguamiento están cumpliendo su función en la conservación de la diversidad acuática y se destaca la importancia de continuar con las estrategias de monitoreo implementadas en el PNNSF, a fin de asegurar el mantenimiento de su diversidad biológica e integridad ambiental.

ABSTRACT Freshwater ecosystems are a primary source of ecosystem services essential for sustaining life and host an important diversity of aquatic species. The knowledge about aquatic macroinvertebrates is precarious in protected areas of Colombia. This study aimed to evaluate the diversity of aquatic macroinvertebrate bioindicators and the ecological quality of habitat in the Selva Florencia National Natural Park (PNNSF). Samples were taken from six micro-watersheds; four points within the park and two in the buffer zone. The diversity index of order Q, variation in species composition, and its relationship with physicochemical variables were performed. To estimate habitat and water quality, the following indexes were used: Habitat Integrity Index (HII), the Riparian Ecosystem Quality Index (RQI), and the BMWP. A total of 2894 aquatic macroinvertebrates were collected. The most representative orders were Ephemeroptera and Trichoptera. The IIH results were moderate to high integrity. The QBR ranged from 65-100, indicating an intermediate, good, and very good quality level. The BMWP indicated that all the tributaries studied are in the category of very good quality waters without evidence of contamination. Finally, it is concluded that the PNNSF and the buffer zone are fulfilling their role in the conservation of aquatic diversity and highlight the importance of continuing with the monitoring strategies implemented in the PNNSF to ensure the maintenance of its biological diversity and environmental integrity.

Dissimilar behavioral and spatial avoidance responses by shrimps from tropical and temperate environments exposed to copper.

Behavioral changes associated with exposure to pollutants represent the earliest response for organisms confronted by perceivable chemical signals. This study was carried out with the objective of evaluating behavioral responses associated with different scenarios of exposure to pollutants (non-forced vs forced) in two shrimp species (Penaeus vannamei and Palaemon varians), representative of different latitudes and using copper as a model contaminant. The effects on locomotion were evaluated by exposing the shrimps to a range of copper concentrations (0, 0.5, 5, 50, and 250 µg/L) in the forced scenario. After exposure, the movement patterns for each shrimp were recorded and used to estimate changes in the shrimps' locomotion. For the non-forced scenario, the avoidance response was assessed by placing shrimps in a multi-compartment system where they were able to move freely along a gradient of copper (0, 0.5, 5, 50, and 250 µg/L). In terms of locomotion, an opposite trend was observed between the species: movements were significantly reduced in P. varians with concentrations above 50 µg/L, while hyperactivity was observed for P. vannamei. When exposed to a gradient of copper in the multi-compartment system, both species significantly avoided the highest concentrations of copper, although the repellence of copper was stronger for P. vannamei. In summary, both species of shrimps were able to recognize and avoid copper; however, in terms of locomotion, they showed an opposite behavioral reaction. These results show that a contamination event can have different behavioral outcomes depending on the species and complementing forced and non-forced exposure with species-specific information can be helpful to characterize and predict the effects of contaminants at higher biological levels.

Effects of Dietary Copper and Escherichia coli Challenge on the Immune Response and Gill Oxidative Balance in the Freshwater Mussel Diplodon chilensis.

Copper is a water and sediment pollutant that can be biomagnified by phytoplankton, and it often co-occurs with fecal bacteria. We addressed the combined effects of copper and Escherichia coli on the immune response and gill oxidative balance of the freshwater mussel Diplodon chilensis. Bivalves were sorted into four groups fed with 1) control algae, 2) bacteria (E. coli), 3) copper-enriched algae (Cu2+ ) algae, and 4) copper-enriched algae followed by bacteria (Cu2+ + E. coli). Cellular and humoral immune and cytotoxic variables were analyzed in hemolymph, and detoxifying/antioxidant enzyme activities (glutathione S-transferase [GST] and catalase [CAT]) and lipid peroxidation (thiobarbituric acid reactive substances [TBARS]) were studied in gill tissue. The total hemocyte number increased after Cu2+ exposure, independently of the E. coli challenge. The proportion of hyalinocytes significantly diminished in the E. coli and Cu2+ groups but not in Cu2+ + E. coli groups; granulocytes significantly increased with E. coli but not with Cu2+ + E. coli treatments. Phagocytic activity was higher in all treatments than in control mussels. Acid phosphatase activity was increased by E. coli and inhibited by Cu2+ and Cu2+ + E. coli. Both E. coli and Cu2+ but not Cu2+ + E. coli augmented alkaline phosphatase activity. The Cu2+ and Cu2+ + E. coli treatments reduced the lysosomal membrane stability and cell viability. Humoral bacteriolytic and phenol oxidase activities were not affected by any treatment. The Cu2+ treatment induced gill CAT and GST activities and increased TBARS levels. The Cu2+ + E. coli treatment reversed this CAT and GST stimulation and increased the Cu2+ effect on TBARS. Dietary Cu2+ affects bivalves' immunological and oxidative status and impairs defensive responses against bacteria. In turn, E. coli potentiates the gill oxidative effects of Cu2+ . Environ Toxicol Chem 2023;42:154-165. © 2022 SETAC.

Synergistic effect of chloroquine and copper to the euryhaline rotifer Proales similis.

Chloroquine (CQ) has been widely used for many years against malaria and various viral diseases. Its important use and high potential to being persistent make it of particular concern for ecotoxicological studies. Here, we evaluated the toxicity of CQ alone and in combination with copper (Cu) to the euryhaline rotifer Proales similis. All experiments were carried out using chronic toxicity reproductive five-day tests and an application factor (AF) of 0.05, 0.1, 0.3, and 0.5 by multiplying the 24-h LC50 values of CQ (4250 µg/L) and Cu (68 µg/L), which were administered in solution. The rate of population increase (r, d-1) ranged from 0.50 to 52 (controls); 0.20 to 0.40 (CQ); 0.09 to 0.43 (Cu); and -0.03 to 0.30 (CQ-Cu) and showed significant decrease as the concentration of both chemicals in the medium increased. Almost all tested mixtures induced synergistic effects, mainly as the AF increased. We found that the presence of Cu intensifies the vulnerability of organisms to CQ and vice versa. These results stress the potential hazard that these combined chemicals may have on the aquatic systems. This research suggests that P. similis is sensitive to CQ as other standardized zooplankton species and may serve as a potential test species in the risk assessment of emerging pollutants in marine environments.

Impacts of urban and industrial pollution on functional traits of benthic macroinvertebrates: Are some traits advantageous for survival?

Urbanization and industrialization produce substantial changes in biodiversity and in the functionality of ecosystems. However, little is known about how anthropic pressures might drive these changes and about their functional consequences. We aimed to determine the responses of macroinvertebrate biological traits to urban and industrial pollution and assess the impacts of these disturbances on the functional diversity of these assemblages. We sampled benthic macroinvertebrates in 27 sites of four basins with different urban disturbance gradients (rural, peri-urban, and urban-industrial), among them the Matanza-Riachuelo River, one of the most polluted basins in the world. We classified macroinvertebrates into 11 traits and 56 categories. Then, we performed an RLQ analysis and computed functional richness, evenness, divergence and Rao diversity indexes for each site and community weighted means for each trait category. The urban and industrial sites (mainly low and middle Matanza-Riachuelo River Basin) showed high concentrations of ammonium, SRP, conductivity, COD, BOD, and organic matter, as well as the lowest values of DO. The functional richness and Rao index of these sites were significantly lower than that of the other sites. Macroinvertebrate traits associated with urban and industrial sites were aerial respiration (spiracles), forms of resistance (eggs or statoblast), cylindrical body shape, oviparity, feeding on microinvertebrates, and full water swimmers. These traits potentially enabled tolerant species persistence at polluted sites while gills, grazers, and crawlers were sensitive to these disturbances. Urban and industrial activities influence biological traits, producing the disappearance or dominance of certain traits in macroinvertebrate assemblages. As a consequence, extreme pollution caused predictable trait-based community changes resulting in reduced functional diversity, and potentially altered the ecosystem function.

Hydrological, Environmental and Taxonomical Heterogeneity during the Transition from Drying to Flowing Conditions in a Mediterranean Intermittent River.

Intermittent rivers and ephemeral streams (IRES) are increasingly studied because of their often-unique aquatic and terrestrial biodiversity, biogeochemical processes and associated ecosystem services. This study is the first to examine the hydrological, physicochemical and taxonomic variability during the dry-wet transition of an intermittent river in the Chilean Mediterranean Zone. Based on 30-years of river monitoring data and the TREHS tool, the hydrology of the river was characterised. Overall, the river shows a significant reduction in streamflow (-0.031 m3/s per year) and a substantial increase of zero flow days (+3.5 days per year). During the transition of hydrological states, variations were observed in the environmental conditions and invertebrate communities. During the drying phase, abundance, richness, and diversity were highest, while species turn-over was highest during base flow conditions. The disconnected pools and the flow resumption phases were characterised by high proportions of lentic taxa and non-insects, such as the endemic species of bivalves, gastropods, and crustaceans, highlighting the relevance of disconnected pools as refuges. Future climatic change scenarios are expected to impact further the hydrology of IRES, which could result in the loss of biodiversity. Biomonitoring and conservation programmes should acknowledge these important ecosystems.

Feeding preferences in aquatic invertebrates associated to Egeria densa in a tropical high-mountain lake / Preferencias alimenticias de invertebrados acuáticos asociados a Egeria densa de un lago de alta montaña tropical

Introduction: The benthic fauna of the littoral zone in lakes is important in transferring energy to other trophic levels, habitat coupling, and helping to keep habitat stability. The study of this type of interactions in lentic systems is priority, since functional aspects about biological communities are unknown. Objective: Describing the trophic relations of aquatic invertebrates of the littoral zone in a tropical high mountain lake by characterizing gut content and stable isotope analysis of δ13C and δ15N. Methods: Samples of benthic invertebrates were collected in the littoral zone of the Lago de Tota where Egeria densa was present using a handheld net method. Samples were processed in the laboratory, organisms were identified, counted and weighed. Gut contents and δ13C and δ15N stable isotopes analysis were performed as well. Results: Records of the trophic relations of aquatic invertebrates, which live in the littoral in high mountain lentic ecosystem in the Neotropics are shown. The analysis of gut contents distinguished seven food items, microphytes and MOPF were the most frequent, and through the stable isotopes analysis (δ15N) we identified four trophic levels, among resources (macrophytes and POM), and consumers (detritivores, herbivores, and predators). The two upper trophic levels concentrated greater diversity and biomass. Conclusion: Most of the organisms studied were linked to omnivorous habits, evidenced in a wide spectrum of food items in their diet. The δ15N values show an enrichment, which occurs due to the effects of the tendency towards eutrophication of the system or due to unknown values of protozoa and bacteria that plays a fundamental role in the diet of these organisms, besides the δ13C values reported in organisms consumes, allows us to suggest an affinity with native resources of the littoral zone.

Introducción: La fauna béntica de la zona litoral de los lagos constituye un vínculo importante en el acoplamiento de hábitats, dinamizando los procesos de transferencia de materia y energía, y con ellos la estabilidad del sistema. El estudio de este tipo de interacciones en sistemas lénticos es prioritario, ya que existen vacíos de información sobre aspectos funcionales que involucran a las comunidades biológicas. Objetivo: Describir las relaciones tróficas de invertebrados acuáticos de la zona litoral de un lago de alta montaña tropical mediante caracterización de contenidos estomacales y análisis de isótopos estables de δ15N y δ13C. Métodos: Se colectaron muestras en la zona litoral del Lago de Tota, asociadas con la presencia de Egeria densa utilizando una red portátil. Las muestras se procesaron en el laboratorio donde los organismos se identificaron, contaron y pesaron. También se realizaron análisis de contenido estomacal e isótopos estables δ13C y δ15N. Resultados: Presentamos registros sobre hábitos tróficos de invertebrados acuáticos de litoral para ecosistemas lénticos de alta montaña del Neotrópico. El análisis de contenido estomacal permitió distinguir siete ítems alimenticios, donde los micrófitos y la MOPF fueron los recursos más frecuentes y el análisis de isótopos estables permitió identificar cuatro niveles tróficos, un nivel basal que hace referencia a los recursos (Macrófitos, MOP) y consumidores detritívoros, herbívoros y depredadores. Los dos niveles tróficos superiores concentraron mayor diversidad y biomasa. Conclusión: La mayor parte de los organismos estudiados fueron vinculados con hábitos omnívoros, evidenciado en un amplio espectro de ítems alimenticios en su dieta. Los valores de δ15N muestran un enriqueciendo que puede deberse a la tendencia del lago hacia la eutroficación o por valores desconocidos de protozoos y bacterias que pueden estar jugando un rol fundamental en la dieta de estos organismos, adicionalmente los valores de δ13C reportados en los organismos consumidores nos permiten sugerir una afinidad hacia recursos propios de la región litoral.

Can nesting waterbirds influence the community structure of macroinvertebrates in southern Brazilian intermittent wetlands? / Podem as colônias de nidificação de aves aquáticas influenciar a estrutura da comunidade de macroinvertebrados em áreas úmidas intermitentes do sul do Brasil?

The main goal of this study was to test the effect of the presence of nesting waterbirds on the taxonomic structure (richness, abundance and composition) of macroinvertebrate communities in southern Brazilian wetlands. Macroinvertebrate communities were seasonally sampled in eight intermittent wetlands differing according to the occurrence of nesting colonies of waterbirds (four with the presence of rookeries; four without). The influence of nutrients and water and sediment physicochemical variables on macroinvertebrate communities was also assessed. The community structure of aquatic macroinvertebrates was not affected by the presence of colonies of nesting waterbirds. Rather, macroinvertebrate communities varied seasonally and they were influenced by water-level environmental variables. Richness and composition changed among seasons and were influenced by nutrients and water physicochemical variables. Water turbidity and total dissolved solids influenced macroinvertebrate richness, while water nutrients affected macroinvertebrate abundance. Our results indicate that the lack of effect of nesting waterbirds on macroinvertebrates is possibly due to the variation in the composition of avian species and their reduced population sizes, and in such cases, any effects of birds on macroinvertebrates can be overridden by water chemistry and seasonal changes in intermittent wetlands.(AU)

O principal objetivo deste estudo foi testar o efeito da presença de colônias de nidificação de aves aquáticas sobre a estrutura taxonômica (riqueza, abundância e composição) de comunidades de macroinvertebrados em áreas úmidas do sul do Brasil. As comunidades de macroinvertebrados foram amostradas sazonalmente em oito áreas úmidas intermitentes, diferindo de acordo com a ocorrência de colônias de nidificação de aves aquáticas (quatro áreas úmidas com e quatro áreas úmidas sem a presença de ninhais). A influência de nutrientes e das variáveis físico-químicas da água e do sedimento nas comunidades de macroinvertebrados também foi avaliada. A estrutura da comunidade de macroinvertebrados aquáticos não foi afetada pela ocorrência de colônias de nidificação de aves aquáticas. No entanto, as comunidades de macroinvertebrados variaram sazonalmente e foram influenciadas pelas variáveis ambientais da água. A riqueza e a composição variaram entre as estações e foram influenciadas pelas variáveis físico-químicas e pelos nutrientes da água. A turbidez e o total de sólidos dissolvidos da água influenciaram a riqueza, enquanto que os nutrientes afetaram a abundância de macroinvertebrados. Nossos resultados indicam que a falta de efeito da presença de colônias de nidificação de aves aquáticas na comunidade de macroinvertebrados é possivelmente devido à variação na composição de espécies de aves e ao tamanho reduzido de suas populações, onde em tais casos, quaisquer efeitos das aves sobre os macroinvertebrados podem ser superados pela química da água e pelas mudanças temporais em áreas úmidas intermitentes.(AU)

Can nesting waterbirds influence the community structure of macroinvertebrates in southern Brazilian intermittent wetlands? / Podem as colônias de nidificação de aves aquáticas influenciar a estrutura da comunidade de macroinvertebrados em áreas úmidas intermitentes do sul do Brasil?

The main goal of this study was to test the effect of the presence of nesting waterbirds on the taxonomic structure (richness, abundance and composition) of macroinvertebrate communities in southern Brazilian wetlands. Macroinvertebrate communities were seasonally sampled in eight intermittent wetlands differing according to the occurrence of nesting colonies of waterbirds (four with the presence of rookeries; four without). The influence of nutrients and water and sediment physicochemical variables on macroinvertebrate communities was also assessed. The community structure of aquatic macroinvertebrates was not affected by the presence of colonies of nesting waterbirds. Rather, macroinvertebrate communities varied seasonally and they were influenced by water-level environmental variables. Richness and composition changed among seasons and were influenced by nutrients and water physicochemical variables. Water turbidity and total dissolved solids influenced macroinvertebrate richness, while water nutrients affected macroinvertebrate abundance. Our results indicate that the lack of effect of nesting waterbirds on macroinvertebrates is possibly due to the variation in the composition of avian species and their reduced population sizes, and in such cases, any effects of birds on macroinvertebrates can be overridden by water chemistry and seasonal changes in intermittent wetlands.

O principal objetivo deste estudo foi testar o efeito da presença de colônias de nidificação de aves aquáticas sobre a estrutura taxonômica (riqueza, abundância e composição) de comunidades de macroinvertebrados em áreas úmidas do sul do Brasil. As comunidades de macroinvertebrados foram amostradas sazonalmente em oito áreas úmidas intermitentes, diferindo de acordo com a ocorrência de colônias de nidificação de aves aquáticas (quatro áreas úmidas com e quatro áreas úmidas sem a presença de ninhais). A influência de nutrientes e das variáveis físico-químicas da água e do sedimento nas comunidades de macroinvertebrados também foi avaliada. A estrutura da comunidade de macroinvertebrados aquáticos não foi afetada pela ocorrência de colônias de nidificação de aves aquáticas. No entanto, as comunidades de macroinvertebrados variaram sazonalmente e foram influenciadas pelas variáveis ambientais da água. A riqueza e a composição variaram entre as estações e foram influenciadas pelas variáveis físico-químicas e pelos nutrientes da água. A turbidez e o total de sólidos dissolvidos da água influenciaram a riqueza, enquanto que os nutrientes afetaram a abundância de macroinvertebrados. Nossos resultados indicam que a falta de efeito da presença de colônias de nidificação de aves aquáticas na comunidade de macroinvertebrados é possivelmente devido à variação na composição de espécies de aves e ao tamanho reduzido de suas populações, onde em tais casos, quaisquer efeitos das aves sobre os macroinvertebrados podem ser superados pela química da água e pelas mudanças temporais em áreas úmidas intermitentes.

Can nesting waterbirds influence the community structure of macroinvertebrates in southern Brazilian intermittent wetlands?

ABSTRACT The main goal of this study was to test the effect of the presence of nesting waterbirds on the taxonomic structure (richness, abundance and composition) of macroinvertebrate communities in southern Brazilian wetlands. Macroinvertebrate communities were seasonally sampled in eight intermittent wetlands differing according to the occurrence of nesting colonies of waterbirds (four with the presence of rookeries; four without). The influence of nutrients and water and sediment physicochemical variables on macroinvertebrate communities was also assessed. The community structure of aquatic macroinvertebrates was not affected by the presence of colonies of nesting waterbirds. Rather, macroinvertebrate communities varied seasonally and they were influenced by water-level environmental variables. Richness and composition changed among seasons and were influenced by nutrients and water physicochemical variables. Water turbidity and total dissolved solids influenced macroinvertebrate richness, while water nutrients affected macroinvertebrate abundance. Our results indicate that the lack of effect of nesting waterbirds on macroinvertebrates is possibly due to the variation in the composition of avian species and their reduced population sizes, and in such cases, any effects of birds on macroinvertebrates can be overridden by water chemistry and seasonal changes in intermittent wetlands.

RESUMO O principal objetivo deste estudo foi testar o efeito da presença de colônias de nidificação de aves aquáticas sobre a estrutura taxonômica (riqueza, abundância e composição) de comunidades de macroinvertebrados em áreas úmidas do sul do Brasil. As comunidades de macroinvertebrados foram amostradas sazonalmente em oito áreas úmidas intermitentes, diferindo de acordo com a ocorrência de colônias de nidificação de aves aquáticas (quatro áreas úmidas com e quatro áreas úmidas sem a presença de ninhais). A influência de nutrientes e das variáveis físico-químicas da água e do sedimento nas comunidades de macroinvertebrados também foi avaliada. A estrutura da comunidade de macroinvertebrados aquáticos não foi afetada pela ocorrência de colônias de nidificação de aves aquáticas. No entanto, as comunidades de macroinvertebrados variaram sazonalmente e foram influenciadas pelas variáveis ambientais da água. A riqueza e a composição variaram entre as estações e foram influenciadas pelas variáveis físico-químicas e pelos nutrientes da água. A turbidez e o total de sólidos dissolvidos da água influenciaram a riqueza, enquanto que os nutrientes afetaram a abundância de macroinvertebrados. Nossos resultados indicam que a falta de efeito da presença de colônias de nidificação de aves aquáticas na comunidade de macroinvertebrados é possivelmente devido à variação na composição de espécies de aves e ao tamanho reduzido de suas populações, onde em tais casos, quaisquer efeitos das aves sobre os macroinvertebrados podem ser superados pela química da água e pelas mudanças temporais em áreas úmidas intermitentes.

Salinity tolerance of a rare and endangered unionid mussel, Popenaias popeii (Texas Hornshell) and its implications for conservation and water management.

Unionid mussels are considered sensitive to salinity and there is growing concern in arid and semi-arid regions that declining flows coupled with anthropogenic impacts are amplifying natural salinity levels. In this study, we tested the effects of varying salinity concentrations (3.0, 4.0, 5.0, 6.0, 7.0 and 10.0 ppt NaCl) on survival of adult Popenaias popeii, (Texas Hornshell). This species occurs in the Rio Grande basin of Texas and northern Mexico, an arid to semi-arid stream plagued by salinization, and was recently listed as Endangered under the U.S. Endangered Species Act. We performed 2, 4, and 10-day toxicity tests on individuals from two disjunct populations: Laredo, TX, and the Lower Canyons of the Rio Grande near Big Bend National Park. We found no significant differences in LC50 estimates between populations at 96-hrs or 10-days but significant differences in TUD50s at 5 ppt between populations, which indicates that tolerance does not vary but sensitivity may between these populations. Overlaying LC50 estimates at 10-days for both populations on plots of salinity (ppt) measured over time, we show parts of the Rio Grande periodically approach or exceed 4.0 ppt, indicating these reaches are becoming unsuitable for P. popeii and populations within them at risk.

Aplicación del índice biótico de familias de macroinvertebrados para la caracterización del agua del río teusacá, afluente del río bogotá / Application of the family biotic index of macroinvertebrates for water characterization of the teusaca river, tributary of the bogota river

RESUMEN La subcuenca del Río Teusacá presenta alta actividad urbanística e industrial en, aproximadamente, el 50% de su superficie, lo cual, ha generado vertimientos de aguas residuales al ambiente acuático. El objetivo de este estudio fue caracterizar la calidad del agua, con base en el Índice Biótico de Familias (IBF), en dos sectores (alto y bajo) del río, en dos temporadas (seca y lluviosa) y analizar la correlación del IBF con: COT, fosfatos, sulfatos, nitratos, nitritos e índices de diversidad. Los muestreos, se realizaron con una red Surber (malla 500 micras y 0,09m2 de área), en 10 sitios, distribuidos en el curso principal: en octubre de 2016, al finalizar una temporada seca y en julio de 2017, al terminar una temporada lluviosa. En total, se registraron 35 taxones y los órdenes con más familias fueron: Diptera (28%), Coleoptera (17%) y Hemiptera (11%). El IBF presentó correlación positiva (>76%) con los contaminantes químicos y se observó que los principales contaminantes del río fueron los fosfatos y el COT, mientras que el IBF con los índices de diversidad, no mostró correlación. La calidad del agua en el sector alto del río estuvo entre buena y regular en ambas temporadas, mientras que en el sector bajo estuvo entre malsana y muy nociva. Estos resultados sugieren que en IBF es un buen indicador de la calidad de agua en los ríos.

ABSTRACT The Teusacá River subbasin presents high industrial and urbanization activities in approximately 50% of its surface, which has generated discharges of waste water and pollutants into the aquatic environment. The aim of this study was to characterize the quality of water based on the insect family biotic index (FBI) in two river sectors (low and high) in two seasons (dry and rainy) and to analyze the FBI correlation with: TOC, phosphates sulphates, nitrates, nitrites and diversity indices. Sampling was carried out in October 2016 and in July 2017 at the end of the dry season and the rainy season, repectively, using a Surber net (500 microns and 0.09m2) at 10 sites, distributed along in the main course of the river. A total of 35 taxa were recorded, the groups with more families were: Diptera (28%), Coleoptera (17%) and Hemiptera (11%). The IBF was significantly and positively correlated with chemical pollutants (>76%) and the main pollutants of the River observed were phosphates and the TOC; while the IBF was not correlated with the diversity indices. The water quality in the high river sector was between good and regular in both seasons; while in the lower river sector it was very harmful and unhealthy. The results obtained suggest that the FBI is an appropriate indicator for determining the water quality of the river.

Responses of macroinvertebrate communities to pesticide application in irrigated rice fields.

The ability to recover to original states after disturbances makes macroinvertebrates useful tools for assessing the impacts of pesticides. Many studies showed that direct exposure to pesticides decreases macroinvertebrate richness and alters their composition. The main objective of this study was to assess recovery patterns in macroinvertebrate communities after pesticide application in irrigated rice fields. We analyzed short-term temporal dynamics of macroinvertebrate communities after application of the herbicides bispyribac-sodium and clomazone and the insecticide chlorantraniliprole, over the rice-growing season in southern Brazil. We selected three conventional rice fields and the recovery of macroinvertebrate communities was also compared with three adjacent natural ponds. The study was developed from November 2011 to February 2012 (rice-growing season). Five macroinvertebrate collections were carried out 3, 7, 14, 38, and 60 days after pesticide application (November 25). Rice fields showed lower richness and abundance than ponds in the period immediately after pesticide application, and recovery rates in the richness of macroinvertebrate communities were more conspicuous as pesticide residuals dissipated from the fields. Macroinvertebrate community structure in rice fields also became more similar to natural ponds as pesticide traces were scarcer. However, macroinvertebrate abundance patterns were not related to pesticide concentrations in the fields. Our results supported the general hypothesis on the negative effects of pesticide application on macroinvertebrate community in irrigated rice fields, although other environmental features (e.g., length of the flooded period) also contributed to explain temporal dynamics in the macroinvertebrate communities from irrigated rice fields.

The Intestinal Microbiota of Tadpoles Differs from Those of Syntopic Aquatic Invertebrates.

Bacterial communities associated to eukaryotes play important roles in the physiology, development, and health of their hosts. Here, we examine the intestinal microbiota in tadpoles and aquatic invertebrates (insects and gastropods) to better understand the degree of specialization in the tadpole microbiotas. Samples were collected at the same time in one pond, and the V4 region of the bacterial 16S rRNA gene was sequenced with Illumina amplicon sequencing. We found that bacterial richness and diversity were highest in two studied snail individuals, intermediate in tadpoles, and lowest in the four groups of aquatic insects. All groups had substantial numbers of exclusive bacterial operational taxonomic units (OTUs) in their guts, but also shared a high proportion of OTUs, probably corresponding to transient environmental bacteria. Significant differences were found for all pairwise comparisons of tadpoles and snails with the major groups of insects, but not among insect groups or between snails and tadpoles. The similarity between tadpoles and snails may be related to similar feeding mode as both snails and tadpoles scratch biofilms and algae from surfaces; however, this requires confirmation due to low sample sizes. Overall, the gut microbiota differences found among syntopic aquatic animals are likely shaped by both food preferences and host identity.

Single and combined effects of microcystin- and saxitoxin-producing cyanobacteria on the fitness and antioxidant defenses of cladocerans.

Cyanobacteria produce different toxic compounds that affect animal life, among them hepatotoxins and neurotoxins. Because cyanobacteria are able to produce a variety of toxic compounds at the same time, organisms may be, generally, subjected to their combined action. In the present study, we demonstrate the single and combined effects on cladocerans of cyanobacteria that produce microcystins (hepatotoxins) and saxitoxins (neurotoxins). Animals were exposed (either singly or combined) to 2 strains of cyanobacteria isolated from the same environment (Funil Reservoir, Rio de Janeiro, Brazil). The effects on clearance rate, mobility, survivorship, fecundity, population increase rate (r), and the antioxidant enzymes glutathione-S-transferase (GST) and catalase (CAT) were measured. Cladoceran species showed a variety of responses to cyanobacterial exposures, going from no effect to impairment of swimming movement, lower survivorship, fecundity, and general fitness (r). Animals ingested cyanobacteria in all treatments, although at lower rates than good food (green algae). Antioxidant defense responses were in accordance with fitness responses, suggesting that oxidative stress may be related to such effects. The present study emphasizes the need for testing combined actions of different classes of toxins, because this is often, and most likely, the scenario in a more eutrophic world with global climatic changes. Environ Toxicol Chem 2017;36:2689-2697. © 2017 SETAC.