Riding the wetland wave: Can ducks locate macroinvertebrate resources across the breeding season?

Food availability varies considerably over space and time in wetland systems, and consumers must be able to track those changes during energetically-demanding points in the life cycle like breeding. Resource tracking has been studied frequently among herbivores, but receives less attention among consumers of macroinvertebrates. We evaluated the change in resource availability across habitat types and time and the simultaneous density of waterfowl consumers throughout their breeding season in a high-elevation, flood-irrigated system. We also assessed whether the macroinvertebrate resource density better predicted waterfowl density across habitats, compared to consistency (i.e., temporal evenness) of the invertebrate resource or taxonomic richness. Resource density varied marginally across wetland types but was highest in basin wetlands (i.e., ponds) and peaked early in the breeding season, whereas it remained relatively low and stable in other wetland habitats. Breeding duck density was positively related to resource density, more so than temporal resource stability, for all species. Resource density was negatively related to duckling density, however. These results have the potential to not only elucidate mechanisms of habitat selection among breeding ducks in flood-irrigated landscapes but also suggest there is not a consequential trade-off to selecting wetland sites based on energy density versus temporal resource stability and that good-quality wetland sites provide both.

Variabilidad de comunidades de macroinvertebrados acuáticos en charcas temporales del norte de Colombia

Introducción: Las charcas temporales son ecosistemas acuáticos variables en su estructura física y biótica, efímeros en el paisaje e importantes en el flujo de materia y energía. Los macroinvertebrados acuáticos constituyen el grupo más abundante y diverso en estos ecosistemas y requieren mayor estudio, particularmente en los trópicos. Objetivo: Evaluar la diversidad alfa y beta de las comunidades de macroinvertebrados acuáticos de seis charcas temporales durante dos épocas climáticas en el norte de Colombia. Métodos: En Magdalena, Colombia, hicimos seis arrastres aleatorios con redes manuales en la zona litoral, y seis arrastres en zigzag con redes tipo D en la zona lacustre; recolectamos macrofauna en tres lances con una draga Ekman; y muestreamos cada charca durante la alta precipitación (noviembre, 2020) y la baja precipitación (febrero, 2021). Resultados: Identificamos 3 358 individuos (13 órdenes, 39 familias y 68 géneros). La mayor abundancia y diversidad (N= 485, 0D= 32) durante la época de lluvia se presentó en Los Campanos, mientras que la charca Villa Leidy tuvo el mayor número de taxones comunes (18) y dominantes (14). En la época de sequía, la charca Los Trillizos presentó la mayor abundancia (533) y diversidad (43); mientras que Villa Leidy y El Miquito el mayor número de taxones dominantes (16). Las charcas tienen composiciones particulares (sin agrupamientos espaciales o temporales); el recambio de taxones es alto, y la correspondencia canónica se agrupa por temporada. Conclusiones: la composición de las comunidades de macroinvertebrados acuáticos de las charcas temporales son muy diversas, presentando alto recambio tanto espacial como temporal, reflejando altos valores de remplazo de taxones entre épocas climáticas. La zona litoral mantuvo una composición similar durante las dos temporadas.

Introduction: Temporary ponds are variable aquatic ecosystems in their physical and biotic structure, ephemeral in the landscape and important in the flow of matter and energy. Aquatic macroinvertebrates constitute the most abundant and diverse group in these ecosystems and need further study, particularly in the tropics. Objective: To evaluate the alpha and beta diversity of the aquatic macroinvertebrate communities of six temporary pools during two climatic seasons in Northern Colombia. Methods: In Magdalena, Colombia, we did six random trawls with hand nets in the coastal zone, and six zig zag trawls with D nets in the lacustrine zone; we collected macrofauna in three random hauls with an Ekman dredge; and sampled each pond in high rainfall (November 2020) and low rainfall (February 2021). Results: We identified 3 358 individuals (13 orders, 39 families and 68 genera). The highest rainy season abundance and diversity (N= 485, 0D= 32) were in Los Campanos, while Villa Leidy Pond had the highest number of common (18) and dominant (14) taxa. During the dry season, Los Trillizos Pond had the highest abundance (533) and diversity (43); while Villa Leidy and El Miquito had the largest number of dominant taxa (16). The pools have a particular composition (no spatial or temporal grouping); taxa turnover is high, and the canonical correspondence clustered by season. Conclusions: The aquatic macroinvertebrate communities of the temporary ponds are diverse and have high turnover in space and time, reflecting high replacement of taxa between climatic periods. The littoral zone had a similar composition in the two seasons.

Determination of the ecological water quality in the Orienco stream using benthic macroinvertebrates in the Northern Ecuadorian Amazon.

In recent years, pollution of watercourses in nearby protected ecosystems has increased due to urbanization. Standard physiochemical methods and probes are one way to monitor watercourses for quality. However, they often do not provide the full ecological status of the body of water. In this work, we set out to assess the ecological water quality of an urban stream by using benthic macroinvertebrates as bioindicators. We conducted the work on the Orienco stream in Lago Agrio in the province of Sucumbíos in the Northern Ecuadorian Amazon (NEA). The stream has become a sink of raw domestic sanitary wastewater from rural and urban areas. A total of 4511 macroinvertebrates from 10 families were identified across 17 sampling points. We compared our results from the biotic indices derived from the macroinvertebrates to standard water-quality parameters (temperature, conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia-nitrogen, and pH) simultaneously sampled in the stream. The standard parameter results indicated that the water-quality levels of the stream met the Ecuadorian water-quality criteria most of the time. However, the results from the biotic indices classified the stream water as poor or very poor water quality. The results from the Biological Monitoring Working Party, Average Score per Taxon, and Family Biotic Indices had overall scores of heavily polluted waters of 45, 4.5, and 8.74, respectively. Furthermore, these results were consistent with reduced richness and evenness, and overall lower Shannon diversity and relatively higher Simpson Dominance indices of 0.71 and 2.56, respectively. We conclude that the macroinvertebrates were better indicators of the ecological water quality of the Orienco stream than the water-quality parameters from standard methods and probes alone. Our findings highlight the need for more integrated ecological assessments, which can provide critical information to the management and conservation strategies of urban watercourses in the NEA region. Integr Environ Assess Manag 2023;19:615-625. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Effects of Pesticides on the Survival of Shredder Nectopsyche sp. (Trichoptera) and Leaf Decomposition Rates in Tropical Andes: A Microcosm Approach.

Andean streams are becoming increasingly impacted by agricultural activities. However, the potential effects of pesticides on their aquatic biodiversity remain unassessed. In order to address this knowledge gap, we conducted an experiment over 37 days in microcosms to assess the effect of two pesticides commonly used in Ecuador (Engeo and Chlorpyrifos) on the aquatic insect Nectopsyche sp. (Trichoptera: Leptoceridae) at 0, 0.10, 5 and 10 µg L-1 concentrations. The highest concentration corresponds to the maximum concentration allowed by the Equatorian legislation. We assessed insect mortality every 24 h, with leaf litter decomposition rates of organic matter determined by deploying Andean alder (Alnus acuminata) dry leaf packs in the microcosms. We found significant mortality of Nectopsyche sp. at high concentrations of Chlorpyrifos, whereas leaf litter was not significantly affected by any of the treatments. We conclude that the environmental legislation of Ecuador might not be fully protecting aquatic biodiversity from pesticide pollution. Further studies are needed, especially when considering that the maximum permitted concentration is very likely exceeded in many areas of the country. We also suggest that the maximum permissible values should be reviewed, considering each pesticide individually.

A survey of aquatic macroinvertebrates in a river from the dry corridor of Nicaragua using biological indices and DNA barcoding.

Aquatic macroinvertebrates are widely used as indicators for water quality assessment around the world. Modern strategies for environmental assessment implement molecular analysis to delimitate species of aquatic macroinvertebrates. Delimitation methods have been established to determine boundaries between species units using sequencing data from DNA barcodes and serve as first exploratory tools for taxonomic revisions. This is useful in regions such as the neotropics where aquatic macroinvertebrate habitats are threatened by human interference and DNA databases remain understudied. We asked whether the biodiversity of aquatic macroinvertebrates in a stream in Nicaragua, within the Central American Dry Corridor, could be characterized with biological indices and DNA barcoding. In this study, we combined regional biological indices (BMWP-CR, IBF-SV-2010) along with distance-based (ASAP, BIN) and tree-based (GMYC, bPTP) delimitation methods, as well as nucleotide BLAST in public barcode databases. We collected samples from the upper, middle, and low reaches of the Petaquilla river. The three sites presented excellent water quality with the BMWP-CR index, but evidence of high organic pollution was found in the middle reach with the IBF-SV-2010 index. We report a total of 219 COI sequences successfully generated from 18 families and 8 orders. Operational taxonomic units (OTUs) designation ranged from 69 to 73 using the four methods, with a congruency of 92% for barcode assignation. Nucleotide BLAST identified 14 species (27.4% of barcodes) and 33 genera (39.3% of barcodes) from query sequences in GenBank and BOLD system databases. This small number of identified OTUs may be explained by the paucity of molecular data from the Neotropical region. Our study provides valuable information about the characterization of macroinvertebrate families that are important biological indicators for the assessment of water quality in Nicaragua. The application of molecular approaches will allow the study of local diversity and further improve the application of molecular techniques for biomonitoring.

Assessment of the stream invertebrate ß -diversity along an elevation gradient using a bidimensional null model analysis.

ß -Diversity, commonly defined as the compositional variation among localities that links local diversity (α-diversity) and regional diversity (γ-diversity), can arise from two different ecological phenomena, namely the spatial species turnover (i.e., species replacement) and the nestedness of assemblages (i.e., species loss). However, any assessment that does not account for stochasticity in community assembly could be biased and misinform conservation management. In this study, we aimed to provide a better understanding of the overall ecological phenomena underlying stream ß -diversity along elevation gradients and to contribute to the rich debate on null model approaches to identify nonrandom patterns in the distribution of taxa. Based on presence-absence data of 78 stream invertebrate families from 309 sites located in the Swiss Alpine region, we analyzed the effect size of nonrandom spatial distribution of stream invertebrates on the ß -diversity and its two components (i.e., turnover and nestedness). We used a modeling framework that allows exploring the complete range of existing algorithms used in null model analysis and assessing how distribution patterns vary according to an array of possible ecological assumptions. Overall, the turnover of stream invertebrates and the nestedness of assemblages were significantly lower and higher, respectively, than the ones expected by chance. This pattern increased with elevation, and the consistent trend observed along the altitudinal gradient, even in the most conservative analysis, strengthened our findings. Our study suggests that deterministic distribution of stream invertebrates in the Swiss Alpine region is significantly driven by differential dispersal capacity and environmental stress gradients. As long as the ecological assumptions for constructing the null models and their implications are acknowledged, we believe that they still represent useful tools to measure the effect size of nonrandom spatial distribution of taxa on ß -diversity.

Ecological relevance of non-perennial rivers for the conservation of terrestrial and aquatic communities.

River conservation efforts traditionally focus on perennial watercourses (i.e., those that do not dry) and their associated aquatic biodiversity. However, most of the global river network is not perennial and thus supports both aquatic and terrestrial biodiversity. We assessed the conservation value of nonperennial rivers and streams (NPRS) in one of Europe's driest regions based on aquatic (macroinvertebrates, diatoms) and terrestrial (riparian plants, birds, and carabid beetles) community data. We mapped the distribution of taxa at 90 locations and across wide environmental gradients. Using the systematic planning tool Marxan, we identified priority conservation sites under 2 scenarios: aquatic taxa alone or aquatic and terrestrial taxa together. We explored how environmental factors (runoff, flow intermittence, elevation, salinity, anthropogenic impact) influenced Marxan's site selection frequency. The NPRS were selected more frequently (over 13% on average) than perennial rivers when both aquatic and terrestrial taxa were considered, suggesting that NPRS have a high conservation value at the catchment scale. We detected an underrepresentation of terrestrial taxa (8.4-10.6% terrestrial vs. 0.5-1.1% aquatic taxa were unrepresented in most Marxan solutions) when priority sites were identified based exclusively on aquatic biodiversity, which points to a low surrogacy value of aquatic taxa for terrestrial taxa. Runoff explained site selection when focusing on aquatic taxa (all best-fitting models included runoff, r2  = 0.26-0.27), whereas elevation, salinity, and flow intermittence were more important when considering both groups. In both cases, site selection frequency declined as anthropogenic impact increased. Our results highlight the need to integrate terrestrial and aquatic communities when identifying priority areas for conservation in catchments with NPRS. This is key to overcoming drawbacks of traditional assessments based only on aquatic taxa and to ensure the conservation of NPRS, especially as NPRS become more prevalent worldwide due to climate change and increasing water demands.

Los esfuerzos de conservación fluvial se enfocan tradicionalmente en los cauces permanentes (aquellos que no se secan) y la biodiversidad acuática asociada. Sin embargo, la mayor parte de la red hidrográfica mundial no es permanente, por lo que sustenta biodiversidad tanto acuática como terrestre. Evaluamos el valor de conservación de los ríos y arroyos no permanentes (RANP) en una de las regiones más secas de Europa con datos de comunidades acuáticas (macroinvertebrados, diatomeas) y terrestres (escarabajos carábidos). Mapeamos la distribución de los taxones en 90 localidades que cubren gradientes ambientales amplios. Con la herramienta de planificación sistemática Marxan identificamos los sitios prioritarios de conservación bajo dos escenarios: considerando sólo los taxones acuáticos o los taxones acuáticos y terrestres juntos. Exploramos cómo los factores ambientales (escorrentía, intermitencia del caudal, altitud, salinidad, impacto antropogénico) influyeron sobre la frecuencia de selección de sitio de Marxan. Los RANP fueron seleccionados con mayor frecuencia (más del 13% en promedio) que los ríos permanentes cuando consideramos los taxones acuáticos y terrestres, lo que sugiere que los RANP tienen un valor elevado de conservación a escala de cuenca. Detectamos que los taxones terrestres estaban infrarrepresentados (8.4-10.6% taxones terrestres vs. 0.5-1.1% acuáticos no tuvieron representación en la mayoría de las soluciones de Marxan) cuando los sitios prioritarios para la conservación se identificaban exclusivamente con la biodiversidad acuática, lo que indica que los taxones acuáticos tienen un reducido valor indicador para los taxones terrestres. La escorrentía determinó la selección de sitios cuando se basó en los taxones acuáticos (los mejores modelos incluyeron la escorrentía, r2 = 0.26-0.27), mientras que la altitud, la salinidad y la intermitencia del caudal fueron más importantes cuando se consideraron ambos grupos. En ambos casos, la frecuencia de selección disminuyó conforme se incrementó el impacto antropogénico. Nuestros resultados resaltan la necesidad de integrar las comunidades terrestres y acuáticas a la identificación de las áreas prioritarias para la conservación de la biodiversidad en cuencas con RANP. Lo anterior es importante para superar las evaluaciones tradicionales basadas solamente en los taxones acuáticos y para garantizar la conservación de los RANP, especialmente ahora que estos son cada vez más frecuentes a nivel mundial debido al cambio climático y a la creciente demanda de agua.

A comparison of genetically and morphometrically identified macroinvertebrate community index scores with implications for aquatic life use attainment.

Measures of aquatic macroinvertebrate communities are often used to characterize water quality and indicate whether waterbodies are meeting management expectations. The accuracy of these measures depends on the skill and experience of the person identifying the macroinvertebrates, and obtaining these measures can be relatively expensive due to the time necessary for identification. Utilizing genetic identification of macroinvertebrate taxa has the potential to reduce the time of sample processing, identify a greater number of taxa, and increase the resolution of identification. We compared Colorado multi-metric index (MMI) scores from seven locations in the Big Thompson River, CO, based on genetic and morphometric identification and estimated the ability of MMI scores based on genetic identification to characterize aquatic life use attainment management thresholds. We found a significant linear relationship (p = 0.002, R2 = 0.87) between MMI scores generated by genetic and morphological identification. MMIs support the following aquatic life use designations as defined by the Colorado Water Quality Control Commission: Impaired < 40, Attaining > 48, and Ambiguous 40-48. These values correspond to MMIs based on genetic identification as Impaired < 20, Attaining > 64, and Ambiguous = 21-63 based on the prediction interval of the regression equation. Our results suggest that using genetically identified macroinvertebrates to estimate MMI scores can provide some degree of certainty regarding aquatic life use designations, and while it may be inappropriate at the current time to entirely replace morphologically based biotic integrity measures with those based on molecular identification, there are opportunities in their use.

Proposed Environmental Risk Management Elements in a Carpathian Valley Basin, within the Rosia Montana European Historical Mining Area.

Non-ferrous metals mining activities have long accompanied people, and began in the study area of South East Europe over 2000 years ago. The environment quality is significantly affected by both historic mining activities and contemporary impacts. All these problems, inducing synergic negative effects on local organism communities, have created a chronic state of pollution. The Corna Valley has one of the oldest historical human impacts in Romania due to the influence of mining. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. The analysis of macroinvertebrate communities, correlated with the lack of fish and some biotope characteristics, indicates that the Corna River presents a variety of categories of ecological status between sectors. The lack of fish reveals the poor ecological conditions. Technical and management solutions are proposed here to diminish the historical environmental problems and to avoid future ecological accidents, especially in an attempt to improve any construction plan concerning a possible new de-cyanidation dam and lake. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. Two management zones were identified, an upper zone which can be used as a reference area and a lower zone, where pollution remedial activities are proposed.

Lumbriculus variegatus (oligochaeta) exposed to polyethylene microplastics: biochemical, physiological and reproductive responses.

Freshwater sediments are a repository of microplastics (MPs) resulting from inland anthropogenic activities. Benthic invertebrates, particularly endobenthic sediment-ingesting species such as the annelid Lumbriculus variegatus (blackworm), are commonly found in contaminated sediments where they likely find and ingest MPs. In the present study, L. variegatus was exposed to concentrations between 0.51 and 20 g kg-1 dry sediment of four size-classes of irregularly-shaped polyethylene MPs (PE-MPs; size-class A: 32-63, B: 63-125, C: 125-250 and D: 250-500 µm) for 48 h to assess their sub-cellular responses to particles ingested, and for 28 days to determine chronic effects on worm's reproduction and biomass. After the short-term exposure (48 h), number of PE-MPs in blackworms' gut were related to MPs concentration in the sediment. In general, PE-MPs ingestion by blackworms induced depletion of their energy reserves (e.g., sugars in all size classes and lipids in the size-classes of PE-MPs > 125 µm), concomitant with the activation of antioxidant and detoxification mechanisms (increased level of total glutathione in all size-classes, and increased glutathione-S-transferase activity in PE-MPs > 250 µm), preventing lipid peroxidation. In addition, it was observed a reduction of aerobic energy production (decreased activity of the electron transport system) and a slight increase in neurotransmission (cholinesterase activity). After a long-term exposure (28 d), the presence and ingestion of PE-MPs did not affect reproduction and biomass of L. variegatus. The activation and efficiency of the antioxidant and detoxification mechanisms allied with the anatomy and physiology of L. variegatus, its feeding strategy and potentially dynamic ingestion/egestion capacity seem to be key features preventing MP deleterious effects under short- and chronic-exposures. Considering the MPs levels reported for freshwater sediments, and despite evidence of MPs ingestion and some sub-organismal effects, our results suggest no adverse impacts of PE-MPs contamination on L. variegatus populations fitness. This study applies an integrative approach in which data concerning the ingestion of different sized MPs and subsequent sub-cellular and apical responses are delivered, raising knowledge on endobenthic invertebrates' strategies to potentially overcome MP toxicity in field contaminated sites.

An image processing method for recognition of four aquatic macroinvertebrates genera in freshwater environments in the Andean region of Colombia.

The aquatic macroinvertebrate community reflects the ecological status of a river. Typically, some extraction methods have been implemented, but the capture and preservation of organisms are necessary. The techniques of digital image processing applied to ecology have become innovative tools for the characterization of aquatic macroinvertebrates. This research implements a methodology for the processing and classification of four aquatic macroinvertebrates genera Thraulodes, Traverella (Ephemeroptera), Anacroneuria (Plecoptera), and Smicridea (Trichoptera) present in three rivers in Antioquia (Colombia), which includes two phases. The first of these was the collection and capture of organisms to obtain a database of the most abundant genera, at laboratory scale. The second was the use of simulations that allow the classification of data through a process of selection and extraction of characteristics using the bag of visual words technique. Of all the classifiers tested, Gaussian vector support machines obtained a percentage of success in the recognition up method of four organisms to the genus level of 97.1 %. The training and computational processing for classification enabled the standardization of an appropriate methodology that will serve as a starting point for aquatic biomonitoring and inventory in Colombia and internationally.

Diversity patterns of aquatic macroinvertebrates in a tropical high-Andean catchment

Introduction: Glacierised catchments are remote and hostile environments, in which streams from different water sources (e.g., glacier melt, rain/snowmelt, groundwater) converge, creating a complex mosaic of stream sites with varying levels of glacial influence and environmental conditions. This environmental heterogeneity, in turn, influences the assemblage and composition of aquatic communities and produces complex patterns of species diversity at the catchment scale. Objectives: In this contribution, we assessed biodiversity and community composition of aquatic macroinvertebrate communities from 51 stream site types in a glacierised catchment in the tropical Andes. The aim of our study was to: (1) determine diversity, rarity, commonness and spatial distribution patterns of aquatic macroinvertebrate communities from sites with different water sources, and (2) identify which environmental variables influence the density and presence of macroinvertebrate taxa and, in particular, of the subfamilies of the ubiquitous chironomids. Methods: Our study sites were grouped according to their water source and to their percentage of glacier coverage in the catchment (GCC). At each site we sampled aquatic macroinvertebrates, measured environmental variables and assessed community differences and environmental influence with ordination analyses and generalized linear models. Results: Kryal and mixed sites had an important proportion of rare taxa. Mean richness was highest in the mixed sites and lowest in the sites with the highest glacier cover; while sites with an intermediate percentage of glacier cover, had the highest values of α and β diversity. We found that 13 taxa (15.9%) were common to all stream site types. SIMPER analysis showed that Orthocladiinae, Hyalella sp. and Andesiops sp. contributed the most to the dissimilarity between site types (˃ 45% of cumulative contribution). RDA showed that kryal sites were associated with high turbidity and density of Podonomids, and with low temperature, amount of CPOM and densities of both Anomalocosmoecus sp. and Andesiops sp. Orthocladinae was associated with high current velocity and chlorophyll a concentration, whereas Hyalella sp. had a positive relationship with higher pH and streambed stability. Generalized linear models showed that GCC was the main variable explaining all faunal metrics. Current velocity explained macroinvertebrate abundance, water temperature was related to chironomid density and chlorophyll a influenced Orthocladiinae presence-absence. Conclusions: Our results suggest that by favoring the presence of rare taxa and taxa turnover, glacier influence may increase biodiversity in glacierised catchments. In terms of biodiversity conservation, this study confirms an urgent need to increase knowledge of high-Andean stream biodiversity, especially in highly heterogenous glacierised catchments, to better describe regional biodiversity patterns and community composition of these highly vulnerable freshwater ecosystems. Detailed analyses of benthic communities and development of databases are key for conservation strategies. Water management municipalities and/or enterprises should consider water quality and stream types for more sustainable management of these important ecosystems.

Introducción: Las cuencas glaciares son entornos remotos y hostiles, en los que los arroyos de diferentes fuentes de agua (p.ej., deshielo de glaciares, lluvia/deshielo, agua subterránea) convergen, creando un mosaico complejo de tramos con diferentes niveles de influencia glacial y condiciones ambientales. Esta heterogeneidad ambiental influye, a su vez, en el ensamblaje y composición de las comunidades acuáticas y produce complejos patrones de diversidad a la escala de la cuenca. Objetivos: En esta contribución, evaluamos la biodiversidad y composición de comunidades de macroinvertebrados acuáticos en 51 sitios de una cuenca glaciar en los Andes tropicales. Los objetivos de nuestro estudio fueron: (1) determinar la diversidad, la contribución de taxones raros y comunes y los patrones de distribución espacial de las comunidades de macroinvertebrados acuáticos en sitios con diferentes fuentes de agua, y (2) identificar qué variables ambientales influyen en la densidad y presencia de taxones de macroinvertebrados y, en particular, de las subfamilias de los omnipresentes quironómidos. Métodos: Agrupamos a nuestros sitios de estudio según su fuente de agua y su porcentaje de cobertura de glaciar en la cuenca (GCC). En cada sitio donde muestreamos macroinvertebrados acuáticos, medimos variables ambientales y evaluamos las diferencias entre comunidades y la influencia ambiental con análisis de ordenación y modelos lineales generalizados. Resultados: Los sitios kryal y mixtos tuvieron una proporción importante de taxones raros. La riqueza media fue más alta en los sitios mixtos y más baja en los sitios con mayor cobertura glaciar; mientras que los sitios con un porcentaje intermedio de cobertura glaciar tuvieron los valores más altos de diversidad α y β. Encontramos que 13 taxones (15,9%) fueron comunes a todos los tipos de sitios de estudio. El análisis SIMPER mostró que Orthocladiinae, Hyalella sp. y Andesiops sp. contribuyeron más a la disimilitud entre tipos de sitios (˃ 45% de la contribución acumulada). El RDA mostró que los sitios kryal estaban asociados con alta turbidez y densidad de podonómidos, y con baja temperatura, cantidad de CPOM y densidad de Anomalocosmoecus sp. y Andesiops sp. Orthocladinae se asoció con una alta velocidad de corriente y concentración de clorofila a, mientras que Hyalella sp. tuvo una relación positiva con pH más alto y estabilidad del lecho del río. Los modelos lineales generalizados mostraron que GCC fue la variable principal para explicar todas las métricas de fauna. La velocidad de corriente explicó la abundancia de macroinvertebrados, la temperatura del agua estuvo relacionada con la densidad de los quironómidos y la clorofila influenció la presencia-ausencia de Orthocladiinae. Conclusiones: Nuestros resultados sugieren que, al favorecer la presencia de taxones raros y la rotación de taxones, la influencia de los glaciares puede aumentar la biodiversidad en cuencas con influencia glaciar. En términos de conservación de la biodiversidad, este estudio confirma la necesidad urgente de incrementar el conocimiento de la biodiversidad en arroyos de la región altoandina, especialmente en cuencas glaciares altamente heterogéneas, para describir mejor los patrones de biodiversidad regional y la composición de las comunidades en estos ecosistemas altamente vulnerables. Análisis detallados de las comunidades bentónicas y el desarrollo de bases de datos son claves para diseñar estrategias de conservación. Los municipios y/o empresas administradoras de agua deben considerar la calidad del agua y los tipos de arroyos para una gestión más sostenible de estos importantes ecosistemas.

Application of deep learning in aquatic bioassessment: Towards automated identification of non-biting midges.

Morphological species identification is often a difficult, expensive, and time-consuming process which hinders the ability for reliable biomonitoring of aquatic ecosystems. An alternative approach is to automate the whole process, accelerating the identification process. Here, we demonstrate an automatic machine-based identification approach for non-biting midges (Diptera: Chironomidae) using Convolutional Neural Networks (CNNs) as a means of increasing taxonomic resolution of biomonitoring data at a minimal cost. Chironomidae were used to build the automatic identifier, as a family of insects that are abundant and ecologically important, yet difficult and time-consuming to accurately identify. The approach was tested with 10 morphologically very similar species from the same genus or subfamilies, comprising 1846 specimens from the South Morava river basin, Serbia. Three CNN models were built utilizing either species, genus, or subfamily data. After training the artificial neural network, images that the network had not seen during the training phase achieved an accuracy of 99.5% for species-level identification, while at the genus and subfamily level all images were correctly assigned (100% accuracy). Gradient-weighted Class Activation Mapping (Grad-CAM) visualized the mentum, ventromental plates, mandibles, submentum, and postoccipital margin to be morphologically important features for CNN classification. Thus, the CNN approach was a highly accurate solution for chironomid identification of aquatic macroinvertebrates opening a new avenue for implementation of artificial intelligence and deep learning methodology in the biomonitoring world. This approach also provides a means to overcome the gap in bioassessment for developing countries where widespread use techniques for routine monitoring are currently limited.

Aquatic Oligochaete Communities in Amazonian Streams, Saracá-Taquera National Forest, Pará, Brazil / Comunidade de oligoquetos aquáticos em riachos amazônicos, Floresta Nacional Saracá-Taquera, Pará, Brasil

Abstract: The aim of this study was to analyze aquatic oligochaete distribution in relation to water column physicochemical variables, structural environmental variation, and predominant substrates in the preserved Amazonian streams of the Saracá-Taquera National Forest (FLONA Saracá-Taquera), northwest Pará, Brazil. Oligochaetes are widely used as bioindicators for monitoring aquatic environments as they are very sensitive to pollution and environmental changes. Physicochemical and structural variables were measured from 100 stream segments in order to understand the distribution of oligochaetes in Amazonian streams. Biotic samples were collected using Surber samplers in three of the most predominant substrate types in each segment. PERMANOVA testing showed that there was a significant difference in the oligochaete community among some substrates, potentially caused by a difference in the abundance of the most common taxa. Canonical Correspondence Analysis showed that physical variables drive the distribution of oligochaetes in preserved Amazonian streams, as they determine the formation of different substrates along the stream, from the source to the mouth; favoring the presence of oligochaetes with more specific ecological needs in low-order streams, and the presence of oligochaetes capable of colonizing various types of substrates and deeper zones in high-order streams. These results suggest that water depth and channel width are the main drivers of aquatic oligochaete distribution along Amazonian streams, determining the formation of unstable and low-quality substrates and, consequently, the low colonization by oligochaetes in high-order streams; and more diverse and stable substrate formation in low-order streams, favoring the colonization by diverse taxa of aquatic oligochaetes in low-order Amazonian streams.

Resumo: O objetivo deste trabalho foi analisar a distribuição da comunidade de oligoquetos em relação às variáveis físico-químicas da coluna da água, variação estrutural do ambiente, e substratos predominantes em riachos amazônicos conservados na FLONA Saracá-Taquera, noroeste do Pará, Brasil. Oligochaetes são amplamente utilizados como bioindicadores para monitoramento de ambientes aquáticos, pois são muito sensíveis à poluição e às mudanças ambientais. Variáveis físico-químicas e estruturais de 100 trechos de riachos foram mensuradas para entender a distribuição de oligoquetos em riachos amazônicos. Amostras bióticas foram coletadas com amostrador Surber em três dos tipos de substratos mais predominantes em cada trecho. A PERMANOVA mostrou que há uma diferença significativa da comunidade de oligoquetos entre alguns substratos, possivelmente baseada nas diferenças no número do táxon mais comum. A Análise de Correspondência Canônica mostrou que as variáveis físicas controlam a distribuição da comunidade de oligoquetos em riachos amazônicos preservados, porque estas variáveis determinam a formação dos diferentes substratos ao longo do riacho, desde a nascente até a foz, favorecendo a presença de oligoquetos com necessidades ecológicas mais específicas em riachos de baixa ordem, e oligoquetos capazes de colonizar diferentes tipos de substrato e zonas mais profundas em riachos de ordem maior. Os resultados deste trabalho sugerem que a profundidade da água e a largura do canal são as variáveis que controlam a distribuição da comunidade de oligoquetos em riachos amazônicos, determinando a formação de substratos instáveis e de baixa qualidade, e consequentemente baixa colonização de oligoquetos, em riachos de ordem maior; e formação de substratos mais diversificados, mais estáveis e de qualidade em riachos de baixa ordem, favorecendo a colonização de diversos taxa de oligoquetos aquáticos em riachos amazônicos de baixa ordem.

Calidad biológica y fisicoquímica de tres fuentes de agua y su relación con el fenómeno de El Niño y La Niña / Biological and physicochemical quality from three water sources and its relation to the El Niño and La Niña phenomenon

RESUMEN En el municipio de El Carmen de Viboral, Antioquia, la cuenca de la quebrada La Cimarronas y sus afluentes Los Andes y La Madera son las principales fuentes de abastecimiento del acueducto de la localidad. Además, en estas y en otras cinco estaciones de muestreo, ubicadas en la parte alta de la microcuenca y sus afluentes, se realizó la evaluación fisicoquímica, microbiológica y biológica, mediante el uso de los macroinvertebrados acuáticos, en tres periodos del ciclo hidrológico de El Niño (2016), los cuales, fueron comparados con tres muestreos del ciclo de La Niña (2011). Se pudo identificar la capacidad de resiliencia ambiental bajo un déficit y exceso de precipitaciones del sistema acuático. Durante el ciclo afectado por El Niño, se presentó mayor concentración de oxígeno disuelto, pH circumneutral, menor temperatura del agua y mayores concentraciones de nitritos, nitrógeno amoniacal y coliformes totales. Durante el ciclo afectado por La Niña, se manifestó mayor temperatura del agua, sólidos totales, dureza, nitratos, fósforo total y mejores condiciones de calidad biológica del agua, según el índice BMWP. No se registraron variaciones estadísticamente significativas del caudal, la temperatura del agua, la conductividad eléctrica y los índices comunitarios (diversidad, equidad, dominancia y riqueza).

ABSTRACT In the municipality of El Carmen de Viboral, Antioquia, the basin of the La Cimarronas stream and its tributaries Los Andes and La Madera, are the main sources of supply of the local aqueduct. In addition, of these, other five sampling stations located in the upper part of the basin and its tributaries, the physico-chemical, microbiological and biological evaluation was carried out through the use of aquatic macroinvertebrates in three periods of the El Niño hydrological cycle (2016), which were compared with three samplings of the La Niña cycle (2011). The capacity of environmental resilience could be identified under a deficit and excess precipitation of the aquatic system. During the cycle affected by El Niño there was a higher concentration of dissolved oxygen, circumneutral pH, lower water temperature and higher concentrations of nitrites, ammonia nitrogen and total coliforms. During the cycle affected by La Niña, there was a higher water temperature, total solids, hardness, nitrates, total phosphorus and better conditions of biological water quality according to the BMWP index. There were no statistically significant variations in flow, water temperature, electrical conductivity and community indices (diversity, equity, dominance and richness).

Comparison of Water Quality Between Two Andean Rivers by Using the BMWP/COL. and ABI. Indices / Comparación de la calidad del agua en dos ríos altoandinos mediante el uso de los índices bmwp/col. y abi

RESUMEN Se comparó la calidad ecológica del río Tota durante agosto 2007 y febrero 2008, y el curso alto del río Bogotá entre los meses de octubre 2013 y enero 2014, aplicando los índices BMWP/Col y ABI. Los puntos de muestreo corresponden a la parte alta, media y baja del gradiente longitudinal. En el río Tota se determinaron 27 familias correspondientes a 11 órdenes, donde las más abundantes fueron Baetidae (25,43 %), Leptohyphidae (16,43 %), Naididae (13,76 %), Chironomidae (11,42 %) y Hyalellidae (10,30 %). En el curso alto del río Bogotá se determinaron 32 familias correspondientes a 13 órdenes, y las más abundantes fueron Chironomidae (28,94 %), Leptoceridae (25,20 %), Naididae (18,34 %) y Simuliidae (8,63 %). En el río Tota, El BMWP/Col. presentó una calidad de agua buena, mientras que el ABI presentó una calidad aceptable. Por otra parte, en la parte alta del Río Bogotá, tanto el BMWP/ Col. como el ABI presentaron variaciones en la calidad del agua entre aceptable y muy crítica. El ACC para el río Tota mostró correlaciones entre la temperatura y conductividad con las familias Hyalellidae y Leptohyphidae mientras que el caudal se relaciona con Sphaeriidae; mientras que el curso alto del río Bogotá se correlacionó el caudal, la conductividad y la temperatura con la familia Veliidae. A manera de conclusión, los resultados obtenidos denotan que el índice ABI, que es un índice creado para sistemas andinos de montaña, es más sensible a los impactos que el índice BMWP/Col.

ABSTRACT The ecological quality of the Tota River was evaluated during August 2007 and February 2008 and compared to the upper part from Bogotá River between October 2013 and January 2014, by applying the BMWP/Col and ABI indexes. The sampling points corresponding to the high, medium and low part of the longitudinal gradient. In the Tota River, 27 families were determined corresponding to 11 orders, where the most abundant were Baetidae (25.43 %), Leptohyphidae (16.43 %), Naididae (13.76 %), Chironomidae (11.42 %) and Hyalellidae (10.30 %). In the upper course of Bogotá River, 32 families were determined to conform 13 orders, where the most abundant were Chironomidae (28.94 %), Leptoceridae (25.20 %), Naididae (18.34 %) and Simuliidae (8.63 %). In the river Tota, The BMWP/Col. The index showed a good status, while the ABI index exhibited an acceptable quality. On the other hand, in the upper part of the Bogotá River, both the BMWP/Col. and ABI showed variations in quality between acceptable and very critical. The CCA for the Tota River exhibited correlations between temperature and conductivity with the families Hyalellidae and Leptohyphidae while the stream flow was linked with the family Sphaeriidae. On the other hand, in the upper part of Bogotá River the stream flow, conductivity and temperature were correlated with the occurrence of the family Veliidae. Our results showed that the ABI index is more sensitive to impacts that the BMWP/Col index is showing its ability to evaluate the Andean mountain systems.

Effects of Wood Density on Aquatic Insect Communities in a Cuban Montane Rainforest Stream.

We tested whether hardness or different wood carbon densities, considered as the concentration of carbon structural compounds, influence functional feeding groups and species richness of aquatic insects in a tropical stream. We expected that harder woods would harbor aquatic insect communities with species richness and functional food group profile different from softwoods. We also expected that collector-gatherers and collector-filterers will be more abundant in softwood because harder woods are less substrate suitable for biofilm production. Aquatic insects associated with the following plants were analyzed: Gomidesia lindeniana with high-density, Psychotria grandis with medium-density, and Meriania leucantha with low-density wood. Diptera and Ephemeroptera were the most abundant groups sampled in the woods. Psychotria grandis shows higher concentrations of lignin, cellulose, and hemicellulose, followed by G. lindeniana and M. leucantha. Breakdown rates are different among plant species with M. leucantha having four times highest breakdown rates and on average three more species in the species richness value. We did not find significant differences in the composition of insect species associated with the plants. We found evidence that the richness and functional organization of aquatic insect communities were mostly related to the breakdown rates and lignin amount of the woods. Plants that decompose faster on average have three more species and two more insect functional groups. Our findings suggest that the loss of high carbon density trees in tropical forests can affect aquatic biodiversity.

Feeding preference of the shredder Phylloicus sp. for plant leaves of Chrysophyllum oliviforme or Miconia chartacea after conditioning in streams from different biomes / Preferência alimentar do fragmentador Phylloicus sp. por folhas de Chrysophyllum oliviforme e Miconia chartacea após condicionadas em riachos de dois biomas

Abstract Macroinvertebrate shredders consume preferably leaves conditioned by fungi and bacteria which offer greater palatability to them. Plant species in Cerrado present high concentration of chemical elements such as lignin and cellulose, phenols and tanins thus making them less attractive for shredders consumption and limiting the palatability. This study aimed to evaluate the feeding preference of a macroinvertebrate shredder of the genus Phylloicus for plant material from two different biomes (Cerrado and Mata Atlântica), after conditioning in a stream of Mata Atlântica and observing their physical and chemical characteristics. Senescent leaves were collected, monthly from the litterfall of riparian vegetation in a 500 m stretch of a stream in each biome from August 2014 to January 201. The most abundant species in each stream was selected for the experiment. The experimental design consisted in with two treatments. The first (T1) comprised leaf discs from Chrysophyllum oliviforme (Cerrado species) together with leaf discs of Miconia chartacea (Atlantic Forest species) which were conditioned in the Atlantic Forest stream. The second treatment (T2) involved leaf discs of Miconia chartacea conditioned in Mata Altlântica and Cerrado streams. Both tests had showed significant differences between the two treatments (T1 and T2). For T1, there was consumption of M. chartacea leaf discs by Phylloicus sp., but there was no consumption of C. oliviforme discs. For T2, there was preference for M. chartaceae leaves conditioned in a stream of Mata Atlântica than in Cerrado stream. The results showed that Phylloicus sp., had presented preference for food detritus of the Mata Antlântica biome and rejection to the one from Cerrado biome.

Resumo Macroinvertebrados fragmentadores consomem folhas preferencialmente condicionadas por fungos e bactérias que lhes oferece uma maior palatabilidade. Nas espécies do cerrado esse condicionamento está também associado às altas concentrações de elementos químicos limitantes à palatabilidade como alto teor de lignina e celulose, que tornam as folhas menos atrativas para os fragmentadores. O trabalho teve como objetivo avaliar a preferência alimentar de macroinvertebrados fragmentador ( Phylloicus sp.) por material vegetal de dois diferentes biomas (Cerrado e Mata Atlântica), após condicionamento em riacho de Mata Atlântica, observando suas características físicas e químicas. Foram coletadas folhas senescentes do aporte vegetal (AV) de espécies nativas da vegetação ripária nesses dois biomas, com periodicidade mensal em um trecho de 500 m de um córrego em cada bioma. O experimento foi delineado com dois tratamentos. O primeiro (T1) compreendeu discos de folhas do Cerrado (Chrysophyllum oliviforme) mais discos de folhas da Mata Atlântica (Miconia chartacea) que foram condicionadas em córrego de Mata Atlântica. O segundo tratamento (T2) envolveu discos de folhas da Mata Atlântica condicionadas em córrego da Mata Atlântica mais discos de folhas da Mata Atlântica condicionadas em córrego do Cerrado. Os dois testes apontaram diferenças significativas entre os dois tratamentos (T1 e T2). Para T1 houve consumo de discos de folha de M. chartacea por Phylloicus sp, mas não houve consumo dos discos de C. oliviforme , de Cerrado. Para T2, houve o consumo, porém a preferência pelas folhas de M. chartaceae condicionadas no córrego da Mata Atlantica foi consideravelmete maior. Os resultados apontam que Phylloicus sp, apresentou preferência alimentar pelo detrito de bioma de Mata Atlântica e rejeição pelo detrito do bioma Cerrado.

The zoocenosis of the Aral Sea: six decades of fast-paced change.

During the last six decades, the water level of the Aral Sea, once one of the largest lakes in the world, has experienced a major human-driven regression followed by significant changes in salinity. These fast-paced alterations were initiated by the diversion of two rivers-the Amu Darya and Syr Darya-key players in the regulation of the water balance of the Aral Sea. Consequently, biological modifications took place leading to severe changes of the zoocenosis. This paper reviews the changes that have affected communities of fish and aquatic invertebrates in the Aral Sea since the 1950s. The reported alterations in biodiversity not only represent a natural response to a decrease in water level and a subsequent increase in salinity but also effects of non-native species introduction. The future prospects for invertebrates and fish in the Aral Sea, assuming that initiated restoration work is continued, are also discussed in this paper.

Adverse impacts of hypoxia on aquatic invertebrates: A meta-analysis.

Hypoxia in aquatic ecosystems is often a result of anthropogenic activities, such as increased nutrient loading, originating from agriculture or urbanization, as well as global warming. Aquatic invertebrates are especially important in ecosystems due to their central role in secondary production and in dynamics of food webs. To better understand impacts of oxygen availability on key physiological processes in invertebrates, we conducted a literature search and synthesized the findings of published studies. We found 55 studies that quantified impacts of hypoxia on feeding, growth, reproduction and respiration rates in 54 different aquatic invertebrate species. We applied non-linear regression models which took into account phylogenetic correlation in the data set. Fitting Michaelis-Menten models, we found that there were differences in how different processes responded to a decline in oxygen availability. Respiration rates were halved at highest oxygen concentration (6.44 mg O2/L), followed by reproductive (3.66 mg O2/L), growth (1.77 mg O2/L) and, finally, feeding rates (0.77 mg O2/L). Our findings confirm observations that reproduction is highly sensitive as organisms quickly reduce their reproductive output when exposed to stressful conditions. As long as they have sufficient reserves, organisms continue growing even under stressful conditions, and we confirmed that growth was not very sensitive to a decline in oxygen availability. We discuss potential impacts of global warming on oxygen availability and demand for aquatic macroinvertebrates. Given that oxygen availability is declining in many ecosystems, we can expect that organismal responses will be increasingly compromised with potential consequences for ecosystems and the services they deliver.