Abstract Benthic macroinvertebrates are integral parts of inland waters, inhabiting a diversity of aquatic ecosystems where communities are spatially structured. Macroinvertebrates of some Mediterranean regions such as North Africa are still not well studied. Due this reason we proposed study the community structure in water bodies located in Northeastern Algeria. For this objective, we sampled 12 different kind of water bodies, two dams, three rivers, and seven streams during the period from October 2020 to September 2021. To biotic and abiotic data, a redundancy analysis (RDA) was applied with the aim of determine the role of both kind of variables for grouping the sites. Also, two types of Null models were considered: species co-occurrence and niche sharing for study the potential associations between species reported. Redundancy analysis showed that water velocity and conductivity were the main drivers of community structure of macroinvertebrates. The species co-occurrence results reveal that species associations are ramdom, except for two sites: El fadjoudj and Ain ben baida corresponding to Seybouse river. At the same time, there is no niche sharing and in consequence, there is no interspecific competition except in the two sites: Salah Salah Salah stream and Bouhamdane dam. The results revealed similarities with other similar studies for Algerian rivers and dams, and with other similar water bodies with Mediterranean climate. waters structured studied Algeria objective 1 dams 202 2021 data RDA (RDA sites Also considered cooccurrence co occurrence reported ramdom river time consequence dam climate 20 2

Resumo Os macroinvertebrados bentônicos são partes integrantes das águas interiores, habitando uma diversidade de ecossistemas aquáticos onde as comunidades estão espacialmente estruturadas. Os macroinvertebrados de algumas regiões mediterrânicas, como o Norte de África, ainda não são bem estudados. Por esta razão propusemos estudar a estrutura comunitária em massas de água localizadas no Nordeste da Argélia. Para tanto, foram amostrados 12 corpos d’água diferentes, duas barragens, três rios e sete córregos durante o período de outubro de 2020 a setembro de 2021. Aos dados bióticos e abióticos foi aplicada uma análise de redundância (RDA) com o objetivo de determinar o papel de ambos os tipos de variáveis para agrupar os sites. Além disso, foram considerados dois tipos de modelos nulos: co-ocorrência de espécies e compartilhamento de nicho para estudar as potenciais associações entre as espécies relatadas. A análise de redundância mostrou que a velocidade e a condutividade da água foram os principais impulsionadores da estrutura da comunidade de macroinvertebrados. Os resultados da co-ocorrência de espécies revelam que as associações de espécies são aleatórias, excepto em dois locais: El fadjoudj e Ain ben baida correspondentes ao rio Seybouse. Ao mesmo tempo, não há partilha de nicho e, consequentemente, não há competição interespecífica, excepto nos dois locais: riacho Salah Salah Salah e barragem de Bouhamdane. Os resultados revelaram semelhanças com outros estudos semelhantes para rios e barragens argelinos, e com outras massas de água semelhantes com clima mediterrânico. interiores estruturadas mediterrânicas África estudados Argélia tanto 1 dágua d diferentes 202 2021 RDA (RDA sites disso nulos coocorrência co ocorrência relatadas aleatórias locais Seybouse tempo consequentemente interespecífica Bouhamdane argelinos mediterrânico 20 2

Resumo O Seybouse é um rio no nordeste da Argélia, é o segundo maior rio, tem uma área de captação de cerca de 6.500 km2 que acolhe cerca de 1,5 milhões de habitantes. Importantes atividades agrícolas e industriais são desenvolvidas nesta bacia hidrográfica. O uso de macroinvertebrados bentônicos como indicadores biológicos tem uma longa tradição em países desenvolvidos e está integrado em todas as avaliações da qualidade ecológica dos sistemas fluviais. O objetivo deste estudo foi revisar o inventário e o papel ecológico dos macroinvertebrados bentônicos nas águas interiores do rio Seybouse e determinar o impacto da poluição em suas distribuições. Resultados semelhantes foram relatados para outros países e rios argelinos. Este estudo enfoca a macrofauna bentônica de Wadi Seybouse e seus afluentes. Foram prospectados 03 locais, um no alto Seybousse Bouhamdane em Medjez Amar e dois no meio Seybousse Salah Salah Salah e Oued Zimba. Entre dezembro de 2019 e maio de 2020, dez parâmetros físico-químicos (pH, CE, DO, velocidade da água, NO3, Salinidade, NO2, MES, turbidez, deth) foram medidos para estabelecer um diagnóstico do estado de saúde desses ecossistemas aquáticos. A abordagem biológica complementar pela análise de populações de macroinvertebrados identificou 7.482 indivíduos e 40 táxons divididos em cinco classes: Crustáceos que são os mais dominantes, Insetos com as ordens principais (Ephemeroptera, Diptera, Trichoptera, Heteroptera e Odonata), Moluscos, Nematóides e Anelídeos. As análises físico-químicas e a aplicação dos índices de poluição orgânica, indicaram uma poluição forte a excessiva para todos os locais especialmente Salah Salah Salah.

Abstract The Seybouse is the second largest river basin in Algeria, hosting an important biodiversity and providing various ecosystem services. This watershed is highly influenced by agricultural and industrial activities, which threaten its biodiversity and ecosystem integrity. The use of benthic macroinvertebrates as biological indicators has a long tradition in developed countries and integrated into all assessments of the ecological quality of river systems. However, the macroinvertebrates of many North African regions are still not well studied, including those of the Seybouse river. The aim of this study is to assess the inventory and ecological role of benthic macroinvertebrates in inland waters of the Seybouse River and determine the impact of pollution on their spatial distributions. We sampled the benthic macrofauna of Wadi Seybouse and its affluents using regular surveys in three sites, of which one was in the upper Seybouse Bouhamdane in Medjez Amar and two in the middle Seybouse. Between December 2019 and May 2020, 10 physico-chemical parameters (pH, EC, OD, water speed, NO3, Salinity, NO2, MES, turbidity, depth) were measured in order to establish a health state diagnosis of these aquatic ecosystems. The complementary biological approach by the analysis of populations of macroinvertebrates identified 7482 individuals and 40 taxa divided into five classes: Crustaceans which were the most dominant, insects with the main orders (Ephemeroptera, Diptera, Trichoptera, Heteroptera and Odonata), Molluscs, Nematodes and Annelids. The physico-chemical analyzes and the application of the organic pollution indices indicated a strong to excessive pollution for all sites, especially in Seybouse upstream

Resumo Objetivo A alta sensibilidade das nascentes à impactos antrópicos deve-se, em grande parte, a elevada conectividade aquático-terrestre existente. A degradação desses ecossistemas pode ser causada pelo uso do solo, como por exemplo o monocultivo de eucalipto. O objetivo deste estudo foi testar a influência de plantações de Eucalyptus urograndis sobre a riqueza, a diversidade da comunidade de macroinvertebrados bentônicos e as variáveis ambientais aferidas em nascentes nos domínios de Floresta Atlântica. Métodos Dez nascentes (5 em áreas de floresta nativa e 5 em áreas de eucalipto) foram amostradas no período seco de 2017. Os organismos foram triados e identificados ao nível de família. Para cada nascente foram mensuradas o oxigênio dissolvido, temperatura, pH, turbidez, condutividade elétrica, sólidos totais dissolvidos, nitrogênio total, nitrito, nitrato, amônia, fósforo total, cobertura vegetal, caracterização granulométrica e matéria orgânica. Resultados O teste t evidenciou algumas variáveis ambientais diferiram, apresentando as áreas de eucalipto maiores valores de sólidos totais dissolvidos e condutividade elétrica e menores de areia muito grossa. No presente estudo, a riqueza e diversidade da fauna bentônica em nascentes foram significativamente menores nas áreas de eucalipto do que nas áreas de vegetação nativa. Entretanto, a composição das comunidades não diferiu. A análise de espécies indicadoras (IndVal) associou Acari, Hydropsychidae, Leptoceridae, Nematoda, Psychodidae e Tipulidae a áreas de floresta nativa. Conclusões Nossos resultados mostram que nascentes em áreas de eucalipto são afetadas pela monocultura reduzindo a riqueza e diversidade de macroinvertebrados bentônicos e alterando também os parâmetros ambientais. Por fim, verificamos que estudos anteriores em outras partes do mundo também se aplicam a áreas neotropicais onde o eucalipto não é nativo. devese, devese deve se, deve-se parte aquáticoterrestre aquático terrestre existente solo Atlântica ( 2017 família dissolvido temperatura pH turbidez total nitrito nitrato amônia vegetal orgânica diferiram grossa Entretanto diferiu IndVal (IndVal Acari Hydropsychidae Leptoceridae Nematoda fim nativo 201 20 2

Abstract Aim The high sensitivity of springs to anthropic impacts is largely due to the high existing aquatic-terrestrial connectivity. The degradation of these ecosystems can be caused by land use, such as eucalyptus monoculture. The aim of this study was to test the influence of Eucalyptus urograndis plantations on the richness and diversity of the benthic macroinvertebrate community and on the environmental variables measured in springs in the Atlantic Forest domains. Methods Ten springs (5 in native forest areas and 5 in eucalyptus area) were sampled in the dry period of 2017. The organisms were screened and identified at the family level. For each spring, dissolved oxygen, temperature, pH, turbidity, electrical conductivity, total dissolved solids, total nitrogen, nitrite, nitrate, ammonia, total phosphorus, vegetation cover, granulometric characterization and organic matter were also measured. Results: The t-test showed that some environmental variables differed, with the eucalyptus areas having higher values of total dissolved solids and electrical conductivity, and lower values of coarse sand. In the present study, the richness and diversity of the benthic fauna of springs were significantly lower in eucalyptus sites than in native sites. Nonetheless, the composition of the communities did not differ. The Indicator Species Analysis (IndVal) associated Acari, Hydropsychidae, Leptoceridae, Nematoda, Psychodidae, and Tipulidae with areas of native forest. Conclusions Our results show that Brazilian springs are affected by eucalyptus monocultures reducing the richness and diversity of benthic macroinvertebrates and also changing water environmental properties. Thus, we verified that previous studies elsewhere in the world also apply to neotropical areas where eucalyptus is not native. aquaticterrestrial aquatic terrestrial connectivity use monoculture domains ( area 2017 level spring oxygen temperature pH turbidity conductivity nitrogen nitrite nitrate ammonia phosphorus cover Results ttest t differed sand Nonetheless differ IndVal (IndVal Acari Hydropsychidae Leptoceridae Nematoda Psychodidae properties Thus 201 20 2

Resumen Introducción: La variabilidad en la estructura de las comunidades acuáticas se atribuye frecuentemente a cambios ambientales, no obstante, en ambientes estables como ríos regulados, las interacciones tróficas podrían ser otro factor ambiental clave determinante de la estructura de estas comunidades. Estas alteraciones podrían provocar un mayor crecimiento de algas y, a su vez, cambios en los grupos funcionales y en la composición de la comunidad de macroinvertebrados favoreciendo la dominancia de determinados grupos de organismos. Objetivo: Identificar el efecto de los cambios ambientales y de la estructura del ficoperifiton sobre la comunidad de macroinvertebrados de ríos Andinos regulados. Métodos: Se analizaron datos ambientales y biológicos recolectados en muestreos trimestrales realizados entre 2010 y 2018 en dos ríos de los Andes Centrales (Antioquia - Colombia), para un total de 27 muestras. La recolección de muestras empleó métodos estandarizados. Se utilizaron diferentes modelos estadísticos para establecer patrones espaciales y temporales de las variables ambientales, de la abundancia y/o densidad y diversidad de ficoperifiton y de los macroinvertebrados, así como las relaciones tróficas que existen entre ellos. Resultados: Se encontró que los ríos regulados presentan relativamente poca variabilidad ambiental. Los parámetros ambientales con mayor variación fueron: temperatura, turbidez y ortofosfatos; las dos últimas variables abióticas fueron las que más aportaron a la inestabilidad bentónica. Conclusión: La presencia de macroinvertebrados raspadores y recolectores fue más afectada por la estabilidad de la densidad del ficoperifiton que por las variables ambientales, evidenciando la importancia de las interacciones tróficas en ríos regulados y el control bottoom up en estos ecosistemas.

Abstract Introduction: The variability in the structure of aquatic communities is frequently attributed to environmental changes; however, in stable environments such as regulated rivers, trophic interactions could be another key environmental factor determining the structure of these communities. These alterations could cause a greater growth of algae, and in turn, changes in the functional groups and in the composition of the macroinvertebrate community favoring the dominance of certain groups of organisms. Objective: To identify the effects of environmental variations and changes in the structure of the phycoperiphyton on the macroinvertebrate community of regulated Andean rivers. Methods: We analyzed environmental and biological data collected in quarterly samples carried out between 2010 and 2018 in two rivers of the Central Andes (Antioquia - Colombia), for a total of 27 samples. Sample collections used standardized methods. Different statistical models were used to establish spatial and temporal patterns of the environmental variables, of the abundance and/or density and diversity of phycoperiphyton and macroinvertebrates, as well as the trophic relationships that exists between them. Results: We found that regulated rivers present relatively little environmental variability. The environmental parameters with the greatest variation were temperature, turbidity, and orthophosphates; these last two were the abiotic variables with the greatest contribution to benthic instability. Conclusion: The presence of scraping and foraging macroinvertebrates was more affected by the stability of the phycoperiphyton density than by environmental variables, showing the importance of trophic interactions in regulated rivers and the bottom up control in these ecosystems.

Abstract Secondary production is the formation of heterotrophic biomass across time, which integrates several important ecological processes that affect the life of organisms, populations, communities and ecosystems, but its study has poor developed in South America. The objectives of this work were to describe the diversity of benthic macroinvertebrate assemblages in terms of abundance and biomass, and to quantify their secondary production for the first time in Andean rivers. A quantitative sampling scheme was implemented, using a Surber sampler, in three forested streams. Physical-chemical variables, nutrients, organic matter and chlorophyll were measured also. The macroinvertebrates were separated and identified mostly at the species level. Each taxon was assigned to a functional feeding group. Secondary production was estimated for 38 taxa, mostly Diptera, Trichoptera, Coleoptera, and Ephemeroptera. The annual production varied from 3769 to 13916 mg dry mass m-2 y-1. Most abundant taxa were also those with higher production, dominated by Ephemeroptera (Baetidae), Trichoptera (Hydropsychidae) and Diptera (Chironomidae and Simuliidae). Density, biomass, and production of collectors and predators were much higher than the other feeding groups. We expect that our results will be useful to evaluate the effects on stream functioning produced by global warming and other anthropogenic disturbances in our region. organisms populations ecosystems America rivers implemented sampler streams Physicalchemical Physical chemical variables nutrients level group 3 Coleoptera 376 1391 m2 m 2 m- y1. y1 y 1. 1 y-1 Baetidae, Baetidae , (Baetidae) Hydropsychidae (Hydropsychidae Chironomidae Simuliidae. Simuliidae . Simuliidae) Density groups region 37 139 y- (Baetidae 13

Abstract Aim In the present study, the structure of the benthic invertebrates in ponds in the presence and absence of Nile tilapia was evaluated. Methods The benthic macroinvertebrates and physicochemical parameters were analyzed for a period of eight weeks, every 15 days, in two ponds (one with fish and the other without fish). Benthic invertebrates were sampled with artificial substrate samplers, made with cheap and common materials, like expanded clay, loofah leaves and gravel. Results With the exception of turbidity, the other physical and chemical variables of water quality were within the ideal limits for tilapia farming. Despite that, there was a significant difference for all physical-chemical parameters monitored, and the average turbidity was much higher in pond with fish. The use of artificial substrate samplers for biomonitoring was effective in the colonization of several taxa in a short period of time (15 days). For benthic community metrics, organism richness, diversity and evenness were significantly higher in the pond without fish. On the other hand, the dominance of Chironomidae and the abundance of Glossiphonidae were much higher in the pond with fish. For Chironomidae, this family was dominant in both treatments, but reached a higher frequency in the pond with fish (98.49%) than in pond without fish (92.87%). The presence of sensitive families, like Leptoceridae (Order Trichoptera), was higher in the pond with no fish, as well as the metric of Ephemeroptera, Plecoptera and Trichoptera families (% EPT). Conclusions The presence of fish altered the macrobenthic community, since metrics of richness and diversity presented lower values in pond with fish. study evaluated weeks 1 days one . fish) materials clay gravel farming that physicalchemical monitored (1 days. days) hand treatments 98.49% 9849 98 49 (98.49% 92.87%. 9287 92.87% 92 87 (92.87%) Order Trichoptera, , Trichoptera) Ephemeroptera % ( EPT. EPT EPT) 98.49 984 9 4 (98.49 928 92.87 8 (92.87% 98.4 (98.4 92.8 (92.87 98. (98. 92. (92.8 (98 (92. (9 (92

Resumo Objetivo No presente estudo, avaliou-se a estrutura de invertebrados bentônicos em viveiros escavados na presença e ausência de tilápia do Nilo. Métodos Os macroinvertebrados bentônicos e os parâmetros físico-químicos foram analisados por um período de oito semanas, a cada 15 dias, em dois viveiros (um com peixes e outro sem peixes). Os invertebrados bentônicos foram coletados com amostradores de substrato artificial, feitos com materiais baratos e comuns, tais como argila expandida, folhas de taboa e brita. Resultados Com exceção da turbidez, as demais variáveis físicas e químicas da qualidade da água estiveram dentro dos limites ideais para o cultivo de tilápia. Apesar disso, houve diferença significativa para todos os parâmetros físico-químicos monitorados, sendo que a turbidez média foi bem maior no tanque com peixes. Para as métricas dos macroinvertebrados bentônicos, riqueza, diversidade e uniformidade de organismos foram significativamente maiores no tanque sem peixes. Por outro lado, a dominância de Chironomidae e a abundância de Glossiphonidae foram muito maiores no tanque com peixes. Para Chironomidae, esta família foi dominante em ambos os tratamentos, mas atingiu maior frequência no viveiro com peixes (98,49%) do que no viveiro sem peixes (92,87%). A presença de famílias sensíveis, como Leptoceridae (Ordem Trichoptera), foi maior no viveiro sem peixes, assim como a métrica das famílias Ephemeroptera, Plecoptera e Trichoptera (% EPT). Conclusões O uso de amostradores de substrato artificial para biomonitoramento mostrou-se eficaz na colonização de diversos táxons em um curto período de tempo (15 dias). Por fim, a presença de peixes alterou a comunidade macrobentônica, já que as métricas de riqueza e diversidade apresentaram valores mais baixos no viveiro escavado com peixes. estudo avaliouse avaliou se Nilo físicoquímicos físico químicos semanas 1 dias . peixes) comuns expandida brita disso monitorados lado tratamentos 98,49% 9849 98 49 (98,49% 92,87%. 9287 92,87% 92 87 (92,87%) sensíveis Ordem Trichoptera, , Trichoptera) Ephemeroptera % ( EPT. EPT EPT) mostrouse mostrou (1 dias. dias) fim macrobentônica 98,49 984 9 4 (98,49 928 92,87 8 (92,87% 98,4 (98,4 92,8 (92,87 98, (98, 92, (92,8 (98 (92, (9 (92

Abstract In order to use sustainable methodologies in the exploration of oil and gas in lentic aquatic systems, a modified methodology (MTR) was implemented in each phase. Simultaneously, water quality, sediment, and organisms were evaluated to detect possible effects. Results included non-compaction of the sediment and less resuspension of dissolved solids and nutrients. Effects such as the increase in blue-green algae and the decrease in benthic macroinvertebrates showed rapid recovery (<15 days) as well as the resuspension of sulfates. Finally, MTR Methodology was feasible, of low magnitude, punctual effect, and rapid recovery for the intervened aquatic systems. systems (MTR phase Simultaneously quality effects noncompaction non compaction nutrients bluegreen blue green <15 15 (<1 days sulfates Finally feasible magnitude effect <1 1 (< < (

ABSTRACT Environmental degradation from human pressures includes the conversion of native vegetation cover into pastures and cropland, as well as riparian deforestation, leading to river siltation, biotic homogenization, and loss of ecosystem services. The objective of our study was to evaluate water quality and benthic macroinvertebrate assemblage structure in response to changes in land use at local and buffer spatial extents. We assumed that human disturbances negatively affect water quality and macroinvertebrate assemblage condition. Greater human influence was observed at the local extent (Local Disturbance Index – LDI) than at the buffer (Buffer Disturbance Index – BDI) extent. Likewise, biological metric responses were stronger relative to the LDI than to the BDI or to the Integrated Disturbance Index (IDI). These results support establishing a biomonitoring program for assessing water body quality in the Doce River basin to facilitate conserving aquatic biodiversity and ecosystem services in the upper Graipu River. cropland deforestation siltation homogenization extents condition Local Buffer Likewise IDI. IDI . (IDI) (IDI

RESUMO A degradação ambiental causada por pressões antrópicas inclui a conversão de cobertura vegetal nativa em pastagens e terras agrícolas, bem como o desmatamento de zonas ripárias, levando ao assoreamento de rios, à homogeneização biótica e à perda de serviços ecossistêmicos. O objetivo do nosso estudo foi avaliar a qualidade de água e a estrutura de assembleia de macroinvertebrados bentônicos em resposta a mudanças no uso da terra em extensões espaciais locais e de microbacia (buffer). Para tanto, assumimos que os distúrbios humanos afetam negativamente a qualidade de água e a assembleia de macroinvertebrados bentônicos. Maior influência humana foi observada na escala local (Índice de Distúrbio Local – LDI) do que na escala de buffer (Índice de Distúrbio Buffer – BDI). Da mesma forma, as respostas das métricas biológicas foram mais correlacionadas ao LDI do que ao BDI ou o Índice Integrado de Distúrbio (IDI). Esses resultados apoiam o estabelecimento de um programa de biomonitoramento para avaliar a qualidade de corpos hídricos na bacia do rio Doce, fomentando a conservação de biodiversidade aquática e serviços ecossistêmicos no alto ribeirão Graipu. agrícolas ripárias rios buffer. . (buffer) tanto BDI. BDI) forma IDI. IDI (IDI) Doce Graipu (buffer (IDI

Abstract Aquatic macroinvertebrates are integral parts of functioning wetlands, inhabiting a diversity of aquatic ecosystems where communities are spatially structured. Macroinvertebrates of some Mediterranean regions such as North Africa are still not well studied. Here, we study the community structure of benthic macroinvertebrates in four different types of lotic and lentic wetlands in the semiarid Haut Plateaux of Northeast Algeria. Macroinvertebrates and 06 physicochemical parameters were sampled in 12 sites belonging to four types of habitats (lotic river, lentic river, dams, and sebkha [saline lentic water body]) during January-December 2021. Eventually, the character lentic-lotic was the most important variable affecting the affecting invertebrate communities in the Mediterranean region. The results revealed that sebkha and dams had a lower Shannon index than lentic and lotic rivers. Non-metric multidimensional scaling analysis showed a strong overlap between the community composition in lotic and lentic sites . Howeverin the three types of aquatic groups lentic river, dam and lotic habitats showed a strong overlap between the community whereas sebkha was markedly separated. Redundancy analysis showed that water velocity and pH, were the main drivers of community structure of macroinvertebrates, revealed a strong effect with pH (F1,8=4.15, P = 0.001) and water velocity (F1,8= 3.22, P = 0.002) , separating lotic communities from those that inhabited dams, lentic rivers, and sebkhas. As conclusion, this study contributes to the better understanding of the community structure of macroinvertebrates in semiarid North Africa where wetlands have been experiencing high anthropogenic disturbance. structured studied Here Algeria 0 1 river saline body body] JanuaryDecember January December 2021 Eventually lenticlotic region rivers Nonmetric Non metric separated F1,8=4.15, F18415 F F1 8 4 15 (F1,8=4.15 0.001 0001 001 F1,8= F18 (F1,8 322 3 22 3.22 0.002 0002 002 sebkhas conclusion disturbance 202 F1,8=4.15 F1841 (F1,8=4.1 0.00 000 00 F1,8 (F1, 32 2 3.2 20 F1,8=4.1 F184 (F1,8=4. 0.0 F1, (F1 3. F1,8=4. (F1,8=4 0. (F F1,8=4

Resumo Macroinvertebrados aquáticos são partes integrantes de zonas úmidas em funcionamento, habitando uma diversidade de ecossistemas aquáticos onde as comunidades são espacialmente estruturadas. Os macroinvertebrados de algumas regiões mediterrâneas, como o norte da África, ainda não foram especificamente analisados. Neste trabalho, almejou-se analisar a estrutura da comunidade de macroinvertebrados bentônicos em 4 tipos diferentes de pântanos lóticos e lênticos no semiárido Haut Plateaux do nordeste da Argélia. Os macroinvertebrados e 6 parâmetros físico-químicos foram amostrados mensalmente em 12 locais pertencentes a 4 categorias de habitats diferentes (rio lótico, rio lêntico, barragens e sebkha - corpo de água salina lêntica) de janeiro a dezembro de 2021. Os resultados revelaram que sebkha e barragens tiveram um pH mais baixo do que os rios lênticos e lóticos. A análise de escala multidimensional não-métrica mostrou uma forte sobreposição entre a composição da comunidade em sítios lóticos e lênticos, mas nos 3 tipos de sítios lênticos, barragem e rio lêntico mostraram uma forte sobreposição, enquanto sebkha foi marcadamente separado. A análise de redundância mostrou que a velocidade da água e o pH foram os principais impulsionadores da estrutura da comunidade de macroinvertebrados, separando as comunidades lóticas daquelas que habitavam barragens, rios lênticos e sebkhas. Assim, à guisa de conclusão, este estudo contribui para a melhor compreensão da estrutura da comunidade de macroinvertebrados no semiárido norte da África, onde as zonas úmidas têm sofrido alta perturbação antrópica. funcionamento estruturadas mediterrâneas África analisados trabalho almejouse almejou se Argélia físicoquímicos físico químicos 1 lótico lêntica 2021 nãométrica métrica separado sebkhas Assim conclusão antrópica 202 20 2

Abstract Rich freshwater biodiversity is threatened by increasing deforestation and disorderly urbanization throughout the Brazilian Amazon, especially in streams and creeks, leading to loss of aquatic habitats. Biological information combined with habitat and water quality are effective tools for rapid assessment. The impact of increasing urbanization was assessed in the Cereja River, eastern Amazonia using a Riparian Habitat Diversity Index (RHDI), benthic macroinvertebrate structure and water and sediment variables in ten areas along the Cereja using multivariate analyzes. Increasing urbanization is associated with lower RHDI, abundance, diversity and equity of benthic macroinvertebrates, higher conductivity, pH, temperature, width and percentage gravel. This information is useful for rapid identification of impacts, assessment of recovery of degraded areas and maintenance of non-degraded areas along urban streams. Amazon creeks habitats River RHDI , (RHDI) analyzes abundance macroinvertebrates conductivity pH temperature gravel impacts nondegraded non (RHDI

Resumen Los humedales altoandinos son sistemas frágiles, vulnerables a la actividad humana y al cambio climático. La región de Arequipa (Perú) posee ecosistemas lóticos y lénticos altoandinos con impactos por la ganadería, piscicultura y represamiento. Se evaluó la comunidad de macroinvertebrados acuáticos de los humedales de Callalli-Oscollo y el posible efecto de las actividades humanas. Desde noviembre de 2017 a octubre de 2018 se realizaron muestreos en 4 estaciones en ambientes lóticos y 2 en lénticos. Los macroinvertebrados se identificaron a nivel de familia. Para evaluar la estructura comunitaria se registró la riqueza, la abundancia relativa, la diversidad de Shannon-Wiener, la dominancia de Simpson, la equidad de Pielou y la diversidad verdadera. Se aplicaron los índices ABI, BMWP/Bol y nPeBMWP para evaluar la calidad ecológica de los ambientes lóticos. En éstos se registraron 30 familias, siendo las más abundantes Chironomidae, Naididae, Limnesiidae, Elmidae, Baetidae y Lumbriculidae. La calidad ecológica fue buena, con excepción de la estación vinculada a la presa que fue dudosa. Los ambientes lénticos registraron 26 familias, siendo las más abundantes Cyprididae, Naididae y Corixidae. Las comunidades de macroinvertebrados en ambientes altoandinos reflejan el estado del ecosistema. Los ambientes vinculados con la actividad humana registran menor calidad ecológica.

Abstract High Andean wetlands are fragile systems, vulnerable to human activity and climate change. In the Arequipa region (Peru), there are high Andean lotic and lentic systems currently affected by livestock raising, fish farming, and dams. The aim of the study was to evaluate the aquatic invertebrate community in the Callalli-Oscollo wetlands and the possible impact of human activities. Samples were taken from November 2017 to October 2018 at 4 sampling stations in lotic environments and 2 in lentic environments. Macroinvertebrates were identified to the family level. The following were determined to evaluate community structure: richness, relative abundance, Shannon-Wiener diversity, Simpson dominance, Pielou evenness, and true diversity. The indices ABI, BMWP/Bol and nPeBMWP were applied to evaluate the ecological quality of the environments sampled. Thirty families were recorded in lotic environments, the most abundant being Chironomidae, Naididae, Limnesiidae, Elmidae, Baetidae and Lumbriculidae. The ecological quality was good, except at the station associated to the dam, where it was doubtful. Twenty-six families were recorded in lentic environments, the most abundant being Cyprididae, Naididae and Corixidae. The macroinvertebrate communities in high Andean environments reflect ecosystem conditions. Environments associated to human activity have lower ecological quality.

Resumen Introducción: El análisis de grupos funcionales de alimentación (GFA) en macroinvertebrados acuáticos es importante para comprender la estructura, función y dinámica de los ecosistemas de procesos ecológicos. La modularidad se refiere al grado de compartimentación de las redes alimentarias y varía entre -1 y 1. Una red con un valor de modularidad cercano a 1 es resistente a las alteraciones y puede interpretarse como un factor indicativo para la estabilidad de las comunidades. Objetivo: En este estudio se analizó la estructura trófica de los macroinvertebrados bentónicos, un elemento importante en la calidad ambiental, en el arroyo La Nitrera, el río San Juan y el río Cauca. Métodos: El estudio contó con el apoyo de técnicas de redes ecológicas utilizando el software Gephi. En 2017 y 2018, estudiamos nueve sitios en estaciones secas, lluviosas y de transición, monitoreando cambios en el gradiente de altitud. En cada uno de los sitios se capturaron y determinaron los organismos y se recogió información fisicoquímica e hidráulica. Resultados: El análisis de componentes de varianza permitió explicar la variabilidad de los datos relacionando las siguientes variables ambientales: GFA, diversidad, riqueza, modularidad, estación y tiempo. La ANOVA simple multifactorial indicó que existen cambios significativos en los GFA en relación con la altitud, y la modularidad con el tiempo. La asignación de los GFA se realizó mediante análisis estomacal e información secundaria. Conclusión: La temporada de transición tuvo la mayor modularidad, posiblemente debido a la recolonización de algunos biotopos provocada por la disminución de la velocidad del cauce. La Nitrera y San Juan presentaron valores superiores a los del Cauca, lo que puede indicar que el cambio altitudinal y la velocidad de las corrientes de agua influyen en la compartimentación de la red.

Abstract Introduction: Analysis of functional feeding groups (FFG) in aquatic macroinvertebrates is important in understanding the structure, function, and dynamics of ecological processes in ecosystems. Modularity refers to the degree of compartmentalization of food webs and varies between -1 and 1. A network with a modularity value close to 1 is resilient to disturbances and can be interpreted as an indicating factor for the stability of communities. Objective: In this study, we analyzed the trophic structure of benthic macroinvertebrates in La Nitrera stream, the San Juan River, and the Cauca River in the Colombian Andes. Methods: The study was supported by ecological networking techniques using Gephi software. We studied nine sites in dry, rainy, and transition seasons in 2017 and 2018, monitoring changes in the altitude gradient. At each of the sites, the organisms were captured and determined, and physicochemical and hydraulic information was obtained. Results: The variance component analysis allowed to explain the variability of the data by relating the following environmental variables: FFG, diversity, richness, modularity, season, and time. Simple multifactorial ANOVA indicated that significant changes in FFG were associated with altitude, and modularity to time. The allocation of the FFG was done by stomach analysis and secondary information. Conclusion: The transition season had the highest modularity, possibly due to the recolonization of some biotopes caused by the decrease in the velocity of water currents. La Nitrera and San Juan presented higher values than the Cauca, which may indicate that the altitudinal change and velocity of water currents affects the compartmentalization of the network.

Resumen Se establecieron dos estaciones en un sector del rio Chotano, con el objetivo de evaluar la calidad del agua, empleando macroinvertebrados bentónicos como bioindicadores, para lo cual se utilizaron índices biológicos: IBMWP, ETP %, diversidad, riqueza, equidad, dominancia, la densidad y grupos tróficos. La recolección de los macroinvertebrados se realizó empleando la red tipo Surber, en dos períodos (seco y lluvioso). En la estación 1 se colectaron en promedio 710 ind/m2 distribuidos en 23 taxones de los órdenes díptera, efemeróptera y tricóptera y en la estación 2 se colectaron 16790 ind/m2 , con 6 taxones de los órdenes haplotaxida y díptera, siendo las especies indicadores de polución orgánica, Chironomus sp, Tubifex sp y Psychoda sp, presentes mayormente en la estación 2. Los índices promedios más altos en la estación 1 a comparación de la estación 2 fueron, IBMWP con 60 puntos indicador de calidad de agua dudosa, moderadamente contaminada y 11 puntos, indicador de calidad muy crítica fuertemente contaminada, la diversidad de Shannon - Wiener 1,33 y 0,30 indicador de aguas con poca diversidad, la equidad de Pielou 0,50 muestran poblaciones más estables y 0,20 menos estables; los índices más bajos en la estación 1 comparando con la estación 2 fueron, dominancia de Simpson 0,37 indicador de poca dominancia y mayor diversidad y 0,9 indicador de mayor dominancia, menor diversidad y mayor polución orgánica.

Abstract Two stations were established in a sector of the Chotano river, with the objective of evaluating the quality of the water, using benthic macroinvertebrates as bioindicators, for which biological indices were used: IBMWP, ETP %, diversity, richness, equity, dominance, density and trophic groups. The collection of macroinvertebrates was carried out using the Surber sampler, in two periods (dry and rainy). In the first season, an average of 710 ind/m2 were collected, classified in 23 taxa of the orders diptera, ephemeroptera and tricoptera, and in the second season 16790 ind/m2 were collected, with 6 taxa of the orders haplotaxide and diptera, the species indicating organic pollution, Chironomus sp, Tubbier sp and Psychoda sp, present mostly in season 2. The highest average indices in season 1 compared to season 2 were IBMWP with 60 points indicating moderately polluted doubtful water quality and 11 points indicating highly polluted critical quality, the diversity of Shannon - Wiener 1,33 and 0,30 indicating waters with limited diversity, the equity of Pielou 0,50 show more stable and 0,20 less stable populations; the lowest indices in station 1 compared to season 2 were, Simpson dominance 0,37 indicator of low dominance and higher diversity and 0,9 indicator of higher dominance, lower diversity and higher organic pollution.

Resumen La minería de metales en Costa Rica, y el uso de sustancias tóxicas en esta actividad, ocasionalmente ha resultado en el abandono negligente de estructuras de desechos que contienen cantidades significativas de metales tóxicos. Estas estructuras que han quedado expuestas a la oxidación y a la meteorización resultan en la liberación ambiental de metales, lo cual propicia la afectación en la calidad natural de los cuerpos de agua superficiales circundantes. El objetivo de la investigación fue determinar que los pasivos mineros abandonados en el Líbano de Tilarán, Guanacaste, son una fuente potencial de contaminación por metales para las aguas, sedimentos y macroinvertebrados bentónicos de los ríos San José y Cañas. Las posibles consecuencias para el medio ambiente asociadas con la presencia de desechos mineros se evaluaron cuantitativa y cualitativamente a través de las cantidades de metales presentes en los desechos y lixiviados. Se realizaron pruebas de infiltración y una prueba cinética de celda húmeda permitió describir los procesos y las reacciones químicas que pueden ocurrir en los desechos mineros durante la lluvia, asociados con la carga de metales en el lixiviado. La presencia de pirita (FeS2) favorece la acidificación del medio y la liberación de metales, se destaca mediante pruebas de difracción de rayos X en muestras de los materiales de desecho. Los resultados muestran un alto contenido de metales (37.8 toneladas de plomo, 20.2 toneladas de arsénico y 0.4 toneladas de cadmio) del total de ~ 106 toneladas en pasivos mineros, la solubilización de estos y otros metales en un medio ácido oxidante (pH: 4.16, CE: 3620 µs / cm y ORP: 275 mV) durante la transición de la estación seca y lluviosa y una carga importante de metales (277 kg / mes de zinc, 234 kg / mes de magnesio, 165 kg / mes de aluminio, 96.1 kg / mes de hierro, 2.68 kg / mes de cadmio, 0.90 kg / mes de arsénico y 0.22 kg / mes de plomo) en lixiviados que llegan al río San José en septiembre. Esta investigación mostró que los pasivos mineros abandonados en el Líbano son una fuente potencial de contaminación por metales para los ecosistemas de agua dulce circundantes.

Abstract Metal mining in Costa Rica, and use of toxic substances in this activity, has occasionally resulted in the negligent abandonment of waste structures containing significant amounts of toxic metals. These structures have been exposed to oxidation and weathering, resulting in the environmental release of metals, thus affecting the quality of the surrounding freshwater ecosystems. The objective of the investigation was to determine to what extent the abandoned mining liabilities in Líbano de Tilarán, Guanacaste, are a potential source of metal contamination for the waters, sediments and benthic macroinvertebrates of the San José and Cañas Rivers. The possible consequences for the environment associated with the presence of mining wastes were quantitatively and qualitatively assessed through the amounts of metals present in the wastes and leachate. Infiltration tests were carried out and a wet cell kinetic test allowed describing the processes and chemical reactions that are likely to occur in mining wastes during rain, associated with the loading of metals in leachate. The presence of pyrite (FeS2), which favors the acidification of the medium and the release of metals, was shown by X-ray diffraction tests on samples of the waste materials. The results show a high content of metals (37.8 tons of lead, 20.2 tons of arsenic and 0.4 tons of cadmium) from the total of ~106 tons in mining liabilities, the solubilization of these and other metals in an oxidizing acid medium (pH: 4.16, EC: 3620 µs / cm and ORP: 275 mV) during the dry-rainy season transition and an important load of metals (277 kg / month of zinc, 234 kg / month of magnesium, 165 kg / month of aluminum, 96.1 kg / month of iron, 2.68 kg / month of cadmium, 0.90 kg / month of arsenic and 0.22 kg / month of lead) in leachates arriving to the San José River in September. This investigation showed that the abandoned mining liabilities in Líbano are a potential source of metal contamination for the surrounding freshwater ecosystems.

ABSTRACT Due to the worrisome water context at domestic and global level, it is imperative to establish actions for protecting and conserving aquatic ecosystems and water resources in Peru, such as establishing a comprehensive assessment of water quality. In this context, bio indicators, especially benthic macroinvertebrates, represent an important tool for efficient water assessment. This essay analyzes how the use of these bio indicators is being managed at international level and within the framework of the National Environmental Management System (SNGA) of Peru, with special emphasis on the National Water Resources Management System (SNGRH), since one of its objectives is to achieve an adequate management of water resources in the country, to contribute to the conservation, preservation and recovery of water and its associated goods, and to have the conservation and protection of water quality as one of its purposes. In this way, it was evident that these bio indicators are being considered in some of the SNGA management instruments. However, in some of these, their use is not very developed or is limited because they do not have a strong legal basis, since they have not yet been incorporated in the regulatory framework of water resources and, therefore, in the protocols that address their use.

RESUMEN Debido al preocupante contexto del agua a nivel nacional y mundial, resulta imperativo establecer acciones para la protección y conservación de los ecosistemas acuáticos y recursos hídricos en el Perú, como instaurar una evaluación integral de la calidad del agua. En este contexto, los bioindicadores, en especial los macroinvertebrados bentónicos, representan una importante herramienta para una eficiente evaluación del agua. En este ensayo se analiza cómo se viene manejando el uso de estos bioindicadores a nivel internacional y en el marco del Sistema Nacional de Gestión Ambiental (SNGA) del Perú, con especial énfasis en el Sistema Nacional de Gestión de Recursos Hídricos (SNGRH). Entre sus objetivos están lograr una adecuada gestión de los recursos hídricos; contribuir en la conservación, preservación y la recuperación del agua y sus bienes asociados y proteger su calidad. El estudio evidenció que estos bioindicadores sí se vienen considerando en algunos de los instrumentos de gestión de los sistemas que conforman el SNGA, sin embargo, su uso no está muy desarrollado al no tener una fuerte base legal. En el caso del SNGRH, su uso es aún incipiente en las estrategias y acciones de sus principales instrumentos de planificación y está ausente en el marco normativo de los recursos hídricos, por ende, en los protocolos que aborden su utilización.