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1.
Rev. biol. trop ; 71(1)dic. 2023.
Article in English | LILACS-Express | LILACS | ID: biblio-1449510

ABSTRACT

Introduction: Chironomidae (Diptera) is the most widespread and abundant aquatic insect family in freshwater ecosystems. Chironomids are considered good indicators of water quality but are seldom identified at the genus level in broad spatial scale studies. Objective: To identify environmental conditions associated with chironomids in an altitudinal gradient. Methods: We compared ecoregions, river types, and seasons, for chironomids in neotropical streams and rivers (18 river sites; 2014-2018; Yungas rainforest and Western Chaco dry forest, Argentina). We used non-metric multidimensional scaling, dissimilarity, envfit analysis and rank-abundance curves. Results: Chironomid "assemblages''matched both ecoregions and river types. However, ecoregions presented a better fit with species composition. The stenothermal taxa of Orthocladiinae were dominant at high elevations and the eurythermal Chironominae in lowland rivers. Altitude, water temperature and conductivity were important. Seasonal differences were smaller than ecoregional differences. Conclusions: Ecoregions, altitude, water temperature and conductivity correlated with chironomid communities. Orthocladiinae were dominant at high elevations and Chironominae in lowland rivers.


Introducción: Chironomidae (Diptera) es la familia de insectos acuáticos más extendida y abundante en los ecosistemas dulceacuícolas. Los quironómidos se consideran buenos indicadores de la calidad del agua, pero rara vez se identifican a nivel de género en estudios de amplia escala espacial. Objetivo: Identificar las condiciones ambientales asociadas a los quironómidos en un gradiente altitudinal. Métodos: Comparamos ecorregiones, tipos de ríos y estaciones para quironómidos en arroyos y ríos neotropicales (18 sitios en ríos; 2014-2018; en un bosque tropical de Yungas y un bosque seco del Chaco Occidental, Argentina). Utilizamos escalamiento no métrico multidimensional, disimilitud, análisis de envfit y curvas de rango-abundancia. Resultados: Los "ensamblajes''de quironómidos coincidieron tanto con las ecorregiones como con los tipos de ríos. Sin embargo, las ecorregiones presentaron un mejor ajuste con la composición de especies. Los taxones estenotérmicos de Orthocladiinae fueron dominantes en las elevaciones altas y los euritermales de Chironominae en los ríos de las tierras bajas. La altitud, la temperatura del agua y la conductividad fueron importantes. Las diferencias estacionales fueron menores que las diferencias ecorregionales. Conclusiones: las ecorregiones, la altitud, la temperatura del agua y la conductividad se correlacionaron con las comunidades de quironómidos. Orthocladiinae fue dominante en los sitios altos y Chironominae en los ríos de tierras bajas.

2.
Medicina (B.Aires) ; 83(5): 719-726, dic. 2023. graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1534875

ABSTRACT

Resumen Introducción : Durante la pandemia de SARS-CoV-2 en Argentina se implementaron intervenciones no farma cológicas que produjeron cambios en la movilidad de la población. El objetivo de este estudio fue relacionar los porcentajes de positividad y la diversidad viral con la movi lidad poblacional durante parte del período de restricciones. Métodos : Estudio retrospectivo analítico realizado en el Instituto Médico Platense durante los años 2020 a 2022 que incluyó 458 pacientes a los que se les tomó un hisopado nasofaríngeo para la búsqueda de patóge nos respiratorios por PCR multiplex. Se analizaron los cambios en la movilidad de la población utilizando los "Informes de Movilidad Local", herramienta desarrollada por Google, cuyos datos son de público acceso. Resultados : La movilidad poblacional se correlacionó significativamente con el porcentaje de positividad de las muestras (p = <0.01; R2 = 0.89) y la diversidad viral (p = 0.04; R2 = 0.78). Discusión : Las intervenciones no farmacológicas destinadas a limitar la propagación del SARS-CoV-2 tuvieron efecto en la circulación de otros virus respi ratorios, hallándose mayor porcentaje de positividad y diversidad a medida que las mismas disminuyeron su grado de restricción.


Abstract Introduction : During the SARS-CoV-2 pandemic, Ar gentina population suffered from significant changes in population mobility due to non-pharmaceutical interventions. The aim of this study was to describe the impact of the mobility restrictions to the rates of positivity and diversity among different respiratory viruses. Methods : Retrospective analytical study per formed at Instituto Médico Platense in La Plata that included 458 patients with nasopharyngeal swab to search for respiratory pathogens by multiplex PCR. Changes in mobility were studied using "Community Mobility Reports", data set developed by Google and publicly available. Results : Community mobility had significant cor relation with the percentages of viral test positiv ity (p = < 0.01; R2=0.89) and viral diversity (p = 0.04; R2 = 0.78). Discussion : Non-pharmaceutical interventions estab lished to contain SARS-CoV-2 spread had a significant impact in the circulation patterns of other respiratory viruses.

3.
Nutr. clín. diet. hosp ; 43(4): 189-196, 13 dec. 2023. tab, graf
Article in Spanish | IBECS | ID: ibc-229969

ABSTRACT

Introducción: La salud mental incluye el bienestar social, psicológico y emocional, y cualquier desequilibrio de este genera limitaciones en el desarrollo físico, personal, comunitario y socioeconómico, mientras que los indicadores antropométricos son medidas corporales importantes para la determinación del estado nutricional. Objetivo: Identificar la relación que existe entre salud mental y los indicadores antropométricos en universitarios deuna universidad privada de Lima-Perú. Material y métodos: La muestra estuvo conformada por 128 universitarios de ciencias de la salud (terapia física y rehabilitación, nutrición y dietética) de ambos sexos, con una edad promedio de 24 años. Se realizaron mediciones antropométricas de peso (kg), talla (cm), circunferencias (cm) y pliegues cutáneos (mm). Se evaluó el índice de masa corpo-ral, índice de cintura cadera y el porcentaje de grasa corpo-ral. Se desarrollaron las pruebas estadísticas U de Mann-Whitney y Rho de Spearman.Resultados: Se evidenció el Índice de masa corporal 43%normal seguido del sobrepeso en 42,2%. El 57,8% de los es-tudiantes presentaron un índice de cintura de cadera muy bajoriesgo cardiovascular, el 22,7% bajo riesgo cardiovascular y el19,5% obtuvo un riesgo cardiovascular alto. En el porcentajede grasa predomina el nivel normal 71,9%, seguido por el18,8% con nivel bajo. Referente a la salud mental se identificóuna relación entre la depresión, ansiedad y estrés con el índicede masa corporal (p= 0,010) y el porcentaje de grasa (p=0,002). Las mujeres presentaron mayor porcentaje de grasaque los varones (p=0,001), respecto al índice de cintura caderalos varones presentan mayor valor que las mujeres (p=0,001). Conclusiones: Se concluye que existe relación entre la sa-lud mental con el índice de masa corporal y el porcentaje degrasa corporal (AU)


ntroduction: Mental health includes social, psychological and emotional well-being, and any imbalance of this generates limitations in physical, personal, community and socioe-conomic development, while anthropometric indicators are important body measurements for the determination of nutritional status. Objective: To identify the relationship between mental health and anthropometric indicators in university students ofa private university in Lima-Peru. Material and methods: The sample consisted of 128 university students of health sciences (physical therapy and rehabilitation, nutrition and dietetics) of both sexes, with an average age of 24 years. Anthropometric measurements of weight (kg), height (cm), circumferences (cm) and skinfolds(mm) were taken. Body mass index, waist hip index and bodyfat percentage were evaluated. Mann-Whitney U andSpearman’s Rho statistical tests were performed.Results: Body mass index was 43% normal followed by42.2% overweight. 57.8% of the students had a waist-to-hipratio with very low cardiovascular risk, 22.7% had lowcardiovascular risk and 19.5% had a high cardiovascular risk.In the percentage of fat, 71.9% was normal, followed by18.8% with a low level. Regarding mental health, a relation-ship was identified between depression, anxiety and stresswith body mass index (p= 0.010) and fat percentage (p=0.002). Females presented a higher percentage of fat thanmales (p=0.001), regarding waist hip index, males presenteda higher value than females (p=0.001). Conclusions: It is concluded that there is a relationshipbetween mental health with body mass index and body fatpercentage (AU)


Subject(s)
Humans , Male , Female , Young Adult , Adult , Students, Health Occupations/psychology , Body Mass Index , Depression/psychology , Anxiety/psychology , Mental Health , Nutritional Status , Anthropometry
4.
Pest Manag Sci ; 79(10): 3959-3969, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37273195

ABSTRACT

BACKGROUND: Sirex noctilio is an invasive forest wasp that affects pines and can result in severe economic losses. The use of semiochemicals offers an opportunity to develop sensitive and specific capturing systems to mitigatenegative impacts. Previous research showed that female S. noctilio would use volatiles emitted by its fungal symbiont, Amylostereum areolatum, but little is known about how these modulate behaviour when combined with pine-wood emissions. Our aim was to understand the relevance of fungal volatiles grown on artificial media and wood from two hosts trees, Pinus contorta and Pinus ponderosa, on behavioural and electroantennographic responses of wasp females. Because background odours can modify an insect's response towards resource-indicating semiochemicals, we propose that the behaviour towards the symbiont (resource) will be modulated by host pine emissions (background odours). RESULTS: Olfactometric assays showed that both host species with fungus were attractive when contrasted against air (P. contorta versus Air, χ2 = 12.19, P < 0.001; P. ponderosa versus Air, χ2 = 20.60, P < 0.001) and suggest a clear hierarchy in terms of female preferences towards the tested stimuli, with response highest towards the fungus grown on P. contorta (olfactory preference index: 5.5). Electrophysiological analyses indicate that females detect 62 volatile compounds from the tested sources. CONCLUSION: Results indicate a strong synergy between symbiont and host semiochemicals, suggesting that the pine species could play a fundamental role in the interaction. Further understanding of the chemical basis of this, could guide the development of specific and attractive lures, in order to maximize attraction of wasps in surveillance programmes. © 2023 Society of Chemical Industry.


Subject(s)
Pinus , Wasps , Animals , Female , Trees , Oviposition , Cues , Symbiosis , Wasps/physiology
5.
Zookeys ; 1167: 57-88, 2023.
Article in English | MEDLINE | ID: mdl-37363740

ABSTRACT

A brief historical review regarding the type locality of Euptychiastigmatica Godman, 1905 was conducted, which suggests that its type locality is actually Rio de Janeiro, Brazil, rather than northeastern Argentina, as previously purported. Consequently, E.stigmatica and its senior synonym E.cyanites Butler, 1871, are regarded to be two species-group names representing a taxon in the euptychiine genus Caeruleuptychia Forster, 1964 known from the Brazilian Atlantic Forest. A lectotype is designated for E.cyanites. Additionally, two closely related species are named and described using an integrative approach with morphological and molecular evidence. Caeruleuptychiaharrisi Nakahara & Freitas, sp. nov. and C.aemulatio Nakahara & Willmott, sp. nov. both occur in Amazonia and COI barcode data recovered these taxa as part of the caerulea clade of Caeruleuptychia.

6.
Conserv Biol ; 37(3): e14093, 2023 06.
Article in English | MEDLINE | ID: mdl-37021387

ABSTRACT

Conservation decisions are invariably made with incomplete data on species' distributions, habitats, and threats, but frameworks for allocating conservation investments rarely account for missing data. We examined how explicit consideration of missing data can boost return on investment in ecosystem restoration, focusing on the challenge of restoring aquatic ecosystem connectivity by removing dams and road crossings from rivers. A novel way of integrating the presence of unmapped barriers into a barrier optimization model was developed and applied to the U.S. state of Maine to maximize expected habitat gain for migratory fish. Failing to account for unmapped barriers during prioritization led to nearly 50% lower habitat gain than was anticipated using a conventional barrier optimization approach. Explicitly acknowledging that data are incomplete during project selection, however, boosted expected habitat gains by 20-273% on average, depending on the true number of unmapped barriers. Importantly, these gains occurred without additional data. Simply acknowledging that some barriers were unmapped, regardless of their precise number and location, improved conservation outcomes. Given incomplete data on ecosystems worldwide, our results demonstrate the value of accounting for data shortcomings during project selection.


Incremento de la restauración de la conectividad a gran escala de los ríos mediantze la planeación de la presencia de barreras sin registro Resumen Las decisiones de conservación se toman con datos incompletos de la distribución, hábitat y amenazas de las especies, pero los marcos para asignar fondos de conservación rara veces lo consideran. Analizamos cómo la consideración explícita de los datos faltantes puede incrementar la rentabilidad de la inversión en la restauración de ecosistemas. Nos enfocamos en el reto que es la restauración de la conectividad entre ecosistemas acuáticos mediante la eliminación de presas y cruces de carreteras en los ríos. Desarrollamos y aplicamos una forma novedosa de integrar la presencia de las barreras sin registro dentro de un modelo de optimización de barreras en el estado de Maine (Estados Unidos) para maximizar la ganancia esperada de hábitat para los peces migratorios. La omisión de las barreras sin registro durante la priorización resultó en una ganancia de hábitat casi 50% menor a la anticipada cuando se usó una estrategia convencional de optimización de barreras. Sin embargo, el reconocimiento explícito de los datos incompletos durante la selección del proyecto incrementó la ganancia esperada de hábitat en un promedio del 20-273%, dependiendo del número real de barreras sin registro. Estas ganancias ocurrieron sin datos adicionales. Los resultados de conservación aumentaron con tan sólo el reconocimiento de que algunas barreras no estaban registradas, sin importar el número y ubicación precisos, Ya que hay datos incompletos para todos los ecosistemas a nivel mundial, nuestros resultados demuestran lo importante que es considerar la carencia de datos durante la selección de proyectos.


Subject(s)
Ecosystem , Rivers , Animals , Conservation of Natural Resources/methods , Fishes
7.
J Environ Manage ; 325(Pt A): 116440, 2023 Jan 01.
Article in English | MEDLINE | ID: mdl-36242970

ABSTRACT

Ecosystem services-based land management incorporates environmental features and social needs, providing an important opportunity to realize global sustainability goals. Recent decades, the interaction among water-related ecosystem services (ESs) is getting ambiguous during regional vegetation restoration, which entails challenges for coordinating restoration actions, economic resources, and water-soil resources' availability. In this study, we first explored mechanism of trade-offs among five water-related ESs in the Chinese Loess Plateau under vegetation restoration. Given the decreased baseflow and its widespread trade-offs with water quality, we then developed four scenarios aiming at enhancing the baseflow and nutrient retention in a cost-effective way, by engaging a spatially explicit biophysical software tool-the RIOS model. Moreover, we selected four typical watersheds in the Loess Plateau as cases to demonstrate the differentiated information on the budget levels and the activity sites. The results indicated that, a deep mechanism of scale effects of trade-off among ESs was largely related to spatial heterogeneity rather than spatial resolution, which also affected activity portfolios under different ES scenarios. For the entire Loess Plateau, activity of forest maintenance should be concentrated on the cost-effective locations of investment for the enhancement of baseflow and nutrient retention. Under the regular budget scenarios, trade-offs only could be locally alleviated in reality, while dropping the high-cost ES objectives is an advisable strategy for minimizing investment risk. Taking conservation agricultural practices in the plain river basins should be regarded as a priority when budget can be increased. In contrast, an approach of 'governing by non-interference' for typical watersheds of re-vegetation was sensible strategy for avoiding trade-offs aggravation. These findings emphasized interrelation between the mechanism of ESs trade-offs and activity portfolios, which is an important basis for the implementation of conservation activities in real world context, and a rational reference for the simulation of desired ES goals in future studies.


Subject(s)
Conservation of Natural Resources , Ecosystem , Conservation of Natural Resources/methods , Cost-Benefit Analysis , Agriculture/methods , Soil , China
8.
Biota Neotrop. (Online, Ed. ingl.) ; 23(2): e20221419, 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1447510

ABSTRACT

Abstract Lotic environments are subjected to the impacts of human activities in an intense way in urban regions and one of the ways to assist in the environmental diagnosis is through the knowledge of the composition of bioindicator organisms, including microalgae. The objective of this work was to qualitatively characterize the Chlorophyceae Class Wille, providing descriptions and meristic data of the specimens as well as the environmental conditions in which the taxa were recorded. Water and phytoplankton samplings were carried out quarterly in 2020, in nine supply rivers, distributed in three river basins in the western region of Paraná (Paraná III basin, Piquiri basin and Baixo Iguaçu basin). The studied rivers were classified as oligotrophic or mesotrophic and the taxa were mostly rare. Thirty-six taxa belonging to the Chlorophyceae class were recorded, distributed in five families: Hydrodictyaceae Dumortier, Neochloridaceae Ettl & Komárek, Radiococcaceae Fott ex P.C.Silva, Scenedesmaceae Oltmanns, Selenastraceae Blackman & Tansley. These taxa have mainly cenobial representatives, with about 70% of the individuals in this thallus configuration, followed by 22% colonies and 8% unicellular thallus. Among the identified species, five occurred only in mesotrophic sites, warning for environments with tendencies to elevate their trophic, since they are genera previously associated with these conditions. Ten new citations were recorded for the State of Paraná, namely: Pseudopediastrum boryanum var. longicorne (Reinsch) P.M.Tsarenko, Radiococcus skujae I.Kostikov, T.Darienko, A.Lukesová & L.Hoffmann, Desmodesmus perforatus (Lemmermann) E.Hegewald, Desmodesmus subspicatus (Chodat) E.Hegewald & A.W.F.Schmidt, Scenedesmus indicus Philipose ex Hegewald, Engelberg & Paschma, Ankistrodesmus bernardii Komárek, Monoraphidium capricornutum (Printz) Nygaard, Monoraphidium caribeum Hindák, Raphidocelis danubiana var. elegans (Playfair) Taşkin & Alp, Selenastrum rinoi Komárek & Comas. Taxonomic studies, such as this one, are an important tool for understanding the flora, and in addition to contributing to the registration of species in aquatic ecosystems, they serve as a basis for ecological studies and other approaches used to preserve biodiversity in these places.


Resumo Ambientes lóticos são ecossistemas muito vulneráveis aos impactos das atividades humanas, especialmente em regiões urbanas, e uma das formas para auxiliar no diagnóstico ambiental é utilizando o conhecimento da composição dos organismos bioindicadores, dentre eles as microalgas. O objetivo foi caracterizar qualitativamente as microalgas enquadradas na Classe Chlorophyceae Wille, fornecendo descrições e dados merísticos dos espécimes bem como as condições ambientais em que os táxons foram registrados. Foram realizadas amostragens de água e de fitoplâncton trimestralmente no ano de 2020, em nove rios de abastecimento, distribuídos em três bacias hidrográficas da região oeste do Paraná (bacia do Paraná III, bacia do Piquiri e bacia do Baixo Iguaçu). Os rios estudados foram enquadrados como oligotróficos ou mesotróficos e os táxons apresentaram em sua maioria ocorrência rara. Foram registrados 36 táxons pertencentes a classe Chlorophyceae distribuídos em cinco famílias: Hydrodictyaceae Dumortier, Neochloridaceae Ettl & Komárek, Radiococcaceae Fott ex P.C.Silva, Scenedesmaceae Oltmanns, Selenastraceae Blackman & Tansley. Esses táxons possuem representantes principalmente cenobiais, apresentando cerca de 70% dos indivíduos nessa configuração de talo, seguido por 22% de colônias e 8% de talos unicelulares. Entre as espécies identificadas, cinco ocorreram somente em locais mesotróficos, advertindo para ambientes com tendências a elevar sua trofia, visto que são gêneros já associados anteriormente a essas condições. Foram registradas 10 novas citações para o Estado do Paraná, sendo estas: Pseudopediastrum boryanum var. longicorne (Reinsch) P.M.Tsarenko, Radiococcus skujae I.Kostikov, T.Darienko, A.Lukesová & L.Hoffmann, Desmodesmus perforatus (Lemmermann) E.Hegewald, Desmodesmus subspicatus (Chodat) E.Hegewald & A.W.F.Schmidt, Scenedesmus indicus Philipose ex Hegewald, Engelberg & Paschma, Ankistrodesmus bernardii Komárek, Monoraphidium capricornutum (Printz) Nygaard, Monoraphidium caribeum Hindák, Raphidocelis danubiana var. elegans (Playfair) Taşkin & Alp, Selenastrum rinoi Komárek & Comas. Trabalhos taxonômicos, como este, são uma importante ferramenta para o conhecimento da flora, e além de contribuir no registro das espécies nos ecossitemas aquáticos, servem como base para estudos ecológicos e demais abordagens utilizadas na preservação da biodiversidade nesses locais.

9.
Rev. biol. trop ; 70(1)dic. 2022.
Article in Spanish | LILACS, SaludCR | ID: biblio-1407247

ABSTRACT

Resumen Introducción: Los ríos tropicales se ven cada vez más afectados por la fragmentación y la regulación; y, en Colombia, se sabe que las represas ponen en peligro a los peces endémicos debido, entre otros, a la migración limitada y la disponibilidad reducida de redes alimenticias basadas en el detrito. Sin embargo, el conocimiento de la ictiofauna nativa afectada por represas en ríos altoandinos es aún incipiente. Objetivo: Evaluar los efectos de la represa del Neusa sobre la ictiofauna. Métodos: Comparamos dos secciones del río, una aguas arriba y otra aguas abajo de la represa con el Sistema Richter IHA, muestreamos tres transectos de 100 m de largo en cada sección, cada dos meses, entre 2017 y 2019. Los peces fueron devueltos al río después de efectuadas las mediciones corporales. Resultados: Recolectamos 729 individuos de cinco familias; los Trichomycterus bogotense eran más pequeños aguas abajo de la represa; Oncorhynchus mykiss fue más pequeño y menos abundante; y no hubo diferencias para Grundulus bogotensis y Eremophilus mutisii. Independientemente de los factores climáticos, O. mykiss y G. bogotensis fueron más abundantes aguas arriba, y E. mutisii y T. bogotense aguas abajo de la represa. Conclusión: Las cinco especies de peces diferían en cómo las poblaciones se diferencian aguas arriba y aguas abajo de la represa, lo que sugiere que algunas se benefician de la represa, mientras que otras se vuelven más pequeñas y menos abundantes.


Abstract Introduction: Tropical rivers are increasingly being affected by fragmentation and regulation; and, in Colombia, dams are known to endanger endemic fishes through, among others, limited migration and reduced availability of sediment-based feeding networks. However, knowledge of native ichthyofauna affected by dams in high Andean rivers is still incipient. Objective: To assess the effects of the Neusa dam on the ichthyofauna. Methods: We compared two rivers' sections, one above and one below the dam with the Richter IHA System, we sampled three 100 m long transects in each section, every two months, between 2017 and 2019. The fishes were returned to the river after body measurements. Results: We collected 729 individuals from five families; Trichomycterus bogotense were smaller under the dam; Oncorhynchus mykiss was smaller and less abundant; and there were no differences for Grundulus bogotensis and Eremophilus mutisii. Independently of climatic factors, O. mykiss and G. bogotensis were more abundant above the dam, and E. mutisii and T. bogotense under the dam. Conclusion: The five fish species differed in how the populations differed above and under the dam, suggesting that some are benefited by the dam, while others become smaller and less abundant.


Subject(s)
Animals , Body Size , Fishes , Colombia
10.
Rev. biol. trop ; 70(1)dic. 2022.
Article in Spanish | LILACS, SaludCR | ID: biblio-1423038

ABSTRACT

Introducción: La fauna de sedimentos del subsuelo, donde se da el intercambio entre aguas subterráneas y superficiales, llamada "fauna hiporreica", cumple funciones ecológicas importantes en los ríos; sin embargo, no ha sido estudiada suficientemente en Colombia. Objetivo: Identificar las relaciones entre los invertebrados hiporreicos y variables fisicoquímicas en el río Dagua, Colombia. Métodos: En tres giras a campo (entre octubre 2017 y diciembre 2018) en cinco estaciones de muestreo a lo largo de la cuenca del río, realizamos perforaciones implementando el método de Karaman-Chappuis (sedimento, agua e invertebrados), y registramos la granulometría y materia orgánica en los sedimentos; además, medimos nutrientes, iones y metales en el agua. Resultados: Las estaciones en la zona de cabecera tuvieron sustratos con sedimentos gruesos (grava y piedra), mayores niveles de oxígeno, y menor temperatura del agua. La riqueza y diversidad de especies fueron mayores en estaciones en la zona cabecera, donde predominaron Copepoda e Insecta, mientras que en sitios de cuenca baja predominaron Arachnida (Hydrachnidiae), Clitellata (Oligochaeta) y Nematoda. Conclusiones: La distribución y abundancia de la fauna hiporreica fueron principalmente influenciadas por cambios en la granulometría del sustrato hiporreico y sus contenidos de materia orgánica.


Introduction: The fauna from the subsurface sediments where groundwaters and surface waters are exchanged, called "hyporheic fauna", fulfills important ecological functions in rivers, but has not been sufficiently studied in Colombia. Objective: To identify relationships between hyporheic invertebrates and physicochemical variables in the Dagua River, Colombia. Methods: In three field trips (between October 2017 and December 2018) to five sites along the river basin, we drilled with the Karaman-Chappuis method (sediment, water, and invertebrates), and recorded granulometry and organic matter in sediments; and nutrients, ions, and metals in water. Results: The headwater stations had substrates with coarser sediments (gravel and stone), higher oxygen levels, and lower water temperature. Both richness and species diversity were higher at the headwater stations, dominated by Copepoda and Insecta, while the lower basin was dominated by Arachnida (Hydrachnidiae), Clitellata (Oligochaeta), and Nematoda. Conclusions: The distribution and abundance of the hyporheic fauna were principally influenced by changes in the granulometry of the hyporheic substrate and its content of organic matter.


Subject(s)
Anthropic Erosion , Biodiversity , Water Pollution , Colombia , Rivers
11.
Conserv Biol ; 36(6): e13982, 2022 12.
Article in English | MEDLINE | ID: mdl-35946319

ABSTRACT

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.


Subject(s)
Ecosystem , Rivers , Conservation of Natural Resources , Environmental Monitoring/methods , Biodiversity
12.
Rev. peru. biol. (Impr.) ; 29(3): e21993, July-Set. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1409968

ABSTRACT

Abstract Chira River is located on the north coast of Peru. The scant information of the ichthyofauna from coastal drainages from Peru is noteworthy. The aim of this study is to characterize the ichthyofauna along the Chira River basin in terms of diversity and altitudinal range distribution. The material examined belongs to the Ichthyological collection of the Natural History Museum (MUSM). The diversity of fishes is composed of 27 species belonging to 19 families and ten orders. Siluriformes and Characiformes were the most diverse, consisting of 22% (six species) for each one. Five species are new records for the Chira River (three natives and two non-natives). Six marine species and seven exotic species were recorded as well. The altitudinal distribution patterns for all species were registered. This study increases the known diversity of freshwater fishes from Pacific Drainage Rivers in Peru, and it could be used for management and conservation plans.


Resumen El río Chira está ubicado en la costa norte del Perú. La escasa información de la ictiofauna de las cuencas costeras del Perú es notable. El objetivo de este estudio es caracterizar la ictiofauna en la cuenca del río Chira en términos de diversidad y rango de distribución altitudinal. El material examinado pertenece a la colección ictiológica del Museo de Historia Natural (MUSM). La diversidad de peces está compuesta por 27 especies pertenecientes a 19 familias y 10 órdenes. Cinco especies son nuevos registros para el río Chira (tres nativas y dos no nativas). Fueron registradas seis especies marinas y siete especies exóticas. Este estudio incrementa el conocimiento de la diversidad de peces de las cuencas costeras en Perú, y puede ser usado para planes de manejo y conservación.

13.
Acta biol. colomb ; 27(1): 28-35, ene.-abr. 2022. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1360046

ABSTRACT

RESUMEN Las emisiones de mercurio (Hg) a partir de actividades de minería afectan los recursos pesqueros, los cuales son importantes en la alimentación proteínica de las poblaciones humanas. El objetivo de este estudio fue analizar las concentraciones de MeHg (metilmercurio) en Prochilodus magdalenae (Bocachico) y Hoplias malabaricus (Moncholo) en hábitats continentales de la región de La Mojana y en la parte baja del río Cauca (Norte de Colombia), sitios que han sido afectados por actividades de minería aurífera. Un total de 160 ejemplares fueron colectados para su respectivo análisis, 130 en el grupo expuesto: Mojana 1 (n=36), Mojana 2 (n=56) y El Bajo Cauca (n=38), y n=30 en el grupo control. Se realizaron las determinaciones de MeHg mediante análisis directo con un Analizador Directo de Mercurio DMA 80, cromatografía líquida y espectrometría de absorción atómica. Las concentraciones de MeHg encontradas en muestras de tejido del músculo dorsal de los peces procedentes de los lugares expuestos, fueron significativamente mayores comparados con el grupo control (p < 0.05), siendo la región del Bajo Cauca la más afectada por altas concentraciones de MeHg. Los resultados indican que la presencia de MeHg en los peces es consecuencia de las actividades de minería aurífera ampliamente desarrolladas en la zona. Estas concentraciones MeHg representan un riesgo mortal para la salud humana y animal.


ABSTRACT Mercury (Hg) pollution from mining activities influence fishing resources, which are important for human populations' nutrition. The aim of this research was to explore MeHg (methylmercury) concentrations in Prochilodus magdalenae (bocachico) and Hoplias malabaricus (moncholo) in freshwater habitats of the Mojana region and in the Bajo Cauca river (Northern Colombia), which have been affected by gold mining activities. A total of 160 individuals were collected, 130 in the exposed group: Mojana 1 (36), Mojana 2 (56) and El Bajo Cauca (38); and 30 individuals in the control group (Cereté). After fish sampling, MeHg determinations were done by direct analysis with a Direct Mercury Analyser DMA 80, liquid chromatography, and atomic absorption spectrometry. The results show that MeHg found in the dorsal muscle tissue is significantly higher than in the control group (p < 0.05), the Bajo Cauca region being the most affected due to the high concentrations of MeHg. The results show that the presence of MeHg in fish may be related to gold mining activities, which are widely developed in the area. The toxic concentrations found represent a risk to human health.

14.
Interface (Botucatu, Online) ; 26: e220056, 2022. tab, ilus
Article in Portuguese | LILACS | ID: biblio-1385954

ABSTRACT

Descrevemos como a organização do sistema de saúde é afetada pelas características da várzea amazônica. Elegemos uma região a oeste do estado do Amazonas que bem caracteriza esse cenário. Entrevistamos gestores de saúde e mapeamos os trajetos percorridos pelos usuários para acessar a rede sanitária. Municípios menores são extremamente dependentes da rede de serviço do polo regional e da capital estadual. O transporte de usuários, à exceção de emergências, é feito por via fluvial com maior tempo e maior custo em relação à via terrestre. O ciclo vazante-cheia também interfere no tempo, no custo e nos agravos prevalentes. Identificamos alguns pontos de tensão entre o instituído normativamente para conformação das regiões de saúde e a realidade regional. Promover saúde na Amazônia passa inevitavelmente pela adaptação e pela resiliência do sistema de saúde no diálogo com as características do território e dos fluxos dos usuários.(AU)


This article describes how the characteristics of the Amazon floodplain affect the organization of local health systems. We chose a region in the west of the state of Amazonas which is characteristic of this situation. We interviewed local health managers and mapped the routes taken by users to access health services. Smaller municipalities are extremely dependent on services in the regional hub and capital of the state. Patients, except emergency patients, are transported via waterways, resulting in longer travel times and higher costs than land routes. The seasonal flooding cycle also affects travel times, costs and prevalent health problems. We identified some points of tension between the rules and regulations governing the configuration of local health regions and the regional reality. Promoting health in the Amazon inevitably requires the health system to adapt and be resilient to local geographical characteristics and patient flows.(AU)


Describimos cómo la organización del sistema de salud se ve afectada por las características de la vega amazónica. Elegimos una región del oeste del Estado de Amazonas que caracteriza bien ese escenario. Entrevistamos a gestores de salud y mapeamos los trayectos recorridos por los usuarios para tener acceso a la red sanitaria. Los municipios menores son extremadamente dependientes de la red de servicio del polo regional y de la capital del estado. El transporte de usuarios, a no ser en casos de emergencia, se realiza por vía fluvial con mayor tiempo y costo con relación a la vía terrestre. El ciclo subida y bajada de las aguas también interfiere en el tiempo, costos y problemas prevalentes. Identificamos algunos puntos de tensión entre lo instituido normativamente para conformación de las regiones de salud y la realidad regional. La promoción de la salud en la Amazonia pasa inevitablemente por la adaptación y resiliencia del sistema de salud en el diálogo con las características del territorio y de los flujos de los usuarios.(AU)


Subject(s)
Humans , Unified Health System , Rural Health Services , Health Services Accessibility , Brazil , Interview , Amazonian Ecosystem
15.
Interface (Botucatu, Online) ; 26: e210361, 2022. ilus
Article in Portuguese | LILACS | ID: biblio-1364992

ABSTRACT

O objetivo do artigo é compartilhar a aprendizagem em pesquisa, fruto da vivência das pesquisadoras e dos pesquisadores na rede de cuidado à saúde de urgência e emergência na Amazônia, Brasil. Propomos pensar no conceito de pesquisa como travessia de fronteiras para falar da interculturalidade, da singularidade do território, mas também do diálogo tenso entre racionalidades da Ciência e das práticas de saúde e de pensamento. O texto está constituído de três eixos: a apresentação da categoria "território líquido", seguida da discussão epistemológica sobre o método e a apresentação dos recursos utilizados na pesquisa para propor uma episteme "emergente e insurgente". Traçamos linhas decolonizadoras do pensamento por entendermos que a função da pesquisa é descrever e produzir visibilidades como existência e não apenas como representação do que está vigente. (AU)


The aim of this article is to share research lessons learnt from the experiences of researchers in the urgent and emergency care network in the Amazon, Brazil. We propose to think about the concept of research as a crossing of boundaries to talk about interculturality, the uniqueness of territories, as well as the tense dialogue between the rationality of science and health practices and thinking. This article is structured into three core sections: presentation of the category "fluid territory", followed by an epistemological discussion of the method and presentation of the resources used in the study to propose an "emergent and insurgent" episteme. We outline decolonizing lines of thought based on the understanding that the function of research is to describe and produce visibility as existence and not just as a representation of what is current. (AU)


El objetivo del artículo es compartir el aprendizaje en investigación, fruto de la vivencia de las investigadoras e investigadores en la red de cuidados de la salud de Urgencias y Emergencias en la Amazonia, Brasil. Proponemos pensar en el concepto de investigación como travesía de fronteras, para hablar de la interculturalidad, de la singularidad del territorio, pero también del diálogo tenso entre racionalidades de la ciencia y de las prácticas de salud y de pensamiento. El texto está formado por tres ejes: la presentación de la categoría "territorio líquido", seguida de la discusión epistemológica sobre el método y presentación de los recursos utilizados en la investigación para proponer una episteme "emergente e insurgente". Trazamos líneas descolonizadoras del pensamiento por entender que la función de la investigación es describir y producir visibilidades como existencia y no solo como representación de lo vigente. (AU)


Subject(s)
Humans , Research/instrumentation , Emergencies , Brazil
16.
Acta biol. colomb ; 26(2): 147-159, mayo-ago. 2021. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1355526

ABSTRACT

RESUMEN Los macroinvertebrados acuáticos son bien conocidos como bioindicadores de la calidad del agua. En Colombia, los estudios sobre este tema se han hecho principalmente a nivel taxonómico de familia. En este trabajo se analizan las respuestas en abundancia, riqueza y diversidad de los dípteros identificados a nivel de género en ríos altoandinos (río Bogotá y río Fucha), en épocas de aguas bajas y aguas altas. Los especímenes se recolectaron con tres métodos: red Surber, red de mano y lavado de rocas. La temperatura promedio fue de 12,9 °C y la saturación de oxígeno estuvo cerca del 100 % o más, con excepción del tramo bajo del río Bogotá antes de Villapinzón. Se colectaron 13 690 dípteros pertenecientes a diez familias y 40 géneros. La riqueza taxonómica fue alta, con una mayor variación en los tramos bajos de las dos corrientes. Las subfamilias de Chironomidae fueron las más abundantes. El análisis de correspondencia canónica (ACC) mostró que los Orthocladiinae se asociaron con la conductividad; el género Gigantodax (Simuliidae) no mostró una relación clara con ninguna variable; por el contrario, el género Simulium se vinculó con el caudal. En términos generales, la asociación entre taxones y variables ambientales fue más clara para los géneros que para las familias, pero no fue suficientemente robusta. Se sugiere que para encontrar un mayor grado de asociación biota-ambiente, es necesario realizar los análisis a nivel de especie, considerando las variaciones locales y temporales.


ABSTRACT Aquatic macroinvertebrates are recognized as bioindicators of water quality. In Colombia, the studies have mainly been addressed by the family taxonomic level. This work analyzes the responses in abundance, richness, and diversity of the Diptera at the genus level in high Andean rivers (Bogotá River and Fucha River), in periods of low and high waters. The specimens were collected with three methods: Surber net, hand net, and rock washing. The average temperature was 12.9 °C and oxygen saturation was close to 100 % or more, except for the lower section of the Bogotá River, before the Villapinzón town. 13 690 Diptera were collected from ten families and 40 genera. Taxonomic richness was high with the greatest variation in the lower sections of the two streams. The Chironomidae subfamilies were the most abundant. Canonical correspondence analysis (CCA) showed that Orthocladiinae were associated with water conductivity; the Gigantodax genus (Simuliidae) did not show a clear relationship with any variable; conversely, the genus Simulium was linked to the caudal. In general terms, the association between taxa and environmental variables was clearer for genera than for families, but it was not robust enough. It is suggested that to find a higher degree of biota-environment association, it is necessary to carry out analyzes at the species level, considering local and temporal variations.

17.
Eng. sanit. ambient ; 26(1): 181-191, jan.-fev. 2021. tab, graf
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1154118

ABSTRACT

RESUMO O efluente sanitário bruto é um dos responsáveis pela poluição de rios urbanos, e a instalação de estações de tratamento de efluentes (ETE) exige uma avaliação comparativa do comportamento desses rios antes e depois da ETE. Este trabalho objetivou avaliar a qualidade da água do rio São Domingos (RSD) após o início da operação da ETE Catanduva (SP), cujas eficiências médias de remoção foram: demanda bioquímica de oxigênio (93,71%), nitrogênio amoniacal (73,12%), fósforo total (25,70%), turbidez (85,16%) e ST (31,75%). Foram utilizados 768 dados coletados pela Companhia Ambiental do Estado de São Paulo a montante e a jusante de Catanduva (SP). Obras de dragagem realizadas durante o período avaliado foram responsáveis por um significativo decréscimo temporário na qualidade da água do RSD em Catanduva. Após dois anos do início da operação da ETE, houve significativa melhoria na qualidade do RSD, com redução das concentrações médias de DBO (de 20,97 para 5,73 mg.L−1), nitrogênio amoniacal (de 3,84 para 0,99 mg.L−1) e Escherichia coli (de 105 para 104 UFC.100 mL−1) e aumento da concentração de oxigênio dissolvido (de 0,90 para 3,12 mg.L−1). A análise de componentes principais indicou que a qualidade do rio a jusante de Catanduva está-se aproximando da boa qualidade verificada a montante da cidade. Esses dados sugerem que o RSD pode futuramente ser classificado como Classe 3 (Resolução do Conselho Nacional do Meio Ambiente — CONAMA n° 357/05) e até ser utilizado para abastecimento humano, reduzindo a elevada demanda de água subterrânea na região.


ABSTRACT Non-treated wastewater is responsible for the pollution of urban rivers, and it is mandatory to evaluate the behavior of these rivers before and after the construction of a Wastewater Treatment Plant (WWTP). The aim of this study was to evaluate the water quality of São Domingos River (SDR) after the start of the Catanduva/SP WWTP operation, whose average removal efficiencies were: biochemical oxygen demand (BOD; 93.71%), ammonia nitrogen (73.12%), total phosphorus (25.70%), turbidity (85.16%), and total solids (31.75%). We used 768 data collected upstream and downstream of the city of Catanduva/SP, previously analyzed by CETESB (state environmental agency). Dredging works carried out during the evaluated period were responsible for a significant temporary worsening in the water quality of the SDR in Catanduva. Two years after the beginning of the Catanduva WWTP, there was a significant improvement in SDR water quality, with a reduction in the average concentrations of BOD (20.97 to 5.73 mg.L−1), ammonia nitrogen (3.84 for 0.99 mg.L−1), and Escherichia coli (105 to 104 CFU.100 mL−1) were reduced; and DO concentration (0.90 to 3.12 mg.L−1) increased. The Principal Component Analysis (PCA) indicated that the water quality of the river downstream of Catanduva is approaching the same quality verified upstream of the city. These data suggest that SDR may be considered a Class 3 river (Resolution CONAMA 357/05) in the future and may even be used for human supply, reducing the high demand for groundwater in the region.

18.
Neotrop. ichthyol ; 19(2): e200123, 2021. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1279489

ABSTRACT

Life-history, geographical barriers, and damming can shape the genetic diversity of freshwater migratory fish, which are particularly vulnerable to anthropogenic impacts. We investigated the genetic diversity of Salminus brasiliensis, a long-distance migratory species that is recognized as an important provider of ecosystem services. We implemented microsatellite analyses to assess genetic diversity and simulate future scenarios for evaluating the long-term viability of dammed and non-dammed populations from the Uruguay River. High levels of genetic diversity were detected for all sampled populations. However, effective population sizes were lower in the uppermost river stretches, where the landscape is highly fragmented. Population structure analysis indicated two spatial genetic populations. It is suggested that this genetic structure preserves populations partially isolated by an ancient natural barrier, instead of being a result of the presence of dams. The simulated genetic scenarios indicated that genetic variability of S. brasiliensis populations from upstream dams could collapse over the years, mainly due to the reduction in the number of alleles. Therefore, besides helping to better understand issues related to the influence of dams on the genetic diversity of migratory fish, our results are especially relevant for driving local fishery policies and management actions for the species conservation.'


História de vida, barreiras geográficas e barramento dos rios podem moldar a diversidade genética de grandes peixes migratórios de água doce, que são particularmente vulneráveis a impactos antrópicos. Nós investigamos a diversidade genética de Salminus brasiliensis, uma espécie migratória de longa distância que é reconhecida como um importante provedor de serviços ecossistêmicos. Realizamos análises de microssatélites para avaliar a diversidade genética e simular cenários futuros, possibilitando estimar a viabilidade em longo prazo de populações situadas em regiões com e sem represas do rio Uruguai. Altos níveis de diversidade genética foram detectados para todas as populações amostradas. Contudo, os tamanhos populacionais efetivos foram menores nos trechos superiores do rio, onde a paisagem é altamente fragmentada. A análise da estrutura populacional indicou duas populações genéticas espaciais. Sugere-se que esta estrutura genética preserva populações parcialmente isoladas por uma antiga barreira natural, ao invés de ser resultado da presença de barragens. Os cenários genéticos simulados indicaram que a variabilidade genética das populações de S. brasiliensis situadas a montante das barragens entraria em colapso ao longo dos anos, principalmente como resultado da redução do número de alelos. Portanto, além de ajudar a entender melhor questões relacionadas à influência de barragens na diversidade genética de peixes migradores, nossos resultados são especialmente relevantes para a condução de políticas pesqueiras locais e ações de manejo para a conservação das espécies.(AU)


Subject(s)
Animals , Genetic Variation , Ecosystem , Characiformes , Fishes , Forecasting , Dams , Genetic Structures
19.
Neotrop. ichthyol ; 19(3): e200133, 2021. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1340232

ABSTRACT

Dams reduce the longitudinal connectivity of rivers and thereby disrupt fish migration and the spatial distribution of species, impacts that remain poorly studied for some Neotropical rivers from mega-diverse basins. We investigated the spatial distribution of fish species with different trophic and movement/reproductive/size characteristics to assess how functional groups have responded to a cascade of dams on the Uruguai River in southern Brazil. Fish abundance, biomass, and species composition were evaluated at eight locations along the longitudinal gradient. The fish assemblage in the upper stretch was mainly characterized by small and medium-sized species at higher trophic levels, whereas the sites located furthest downstream displayed more medium and large-sized species, including many carnivorous species. Species with high fecundity, seasonal migrants, and catfishes with internal fertilization were common in the river´s middle and lower reaches. Detritivorous species dominated areas distant from the dams. Overall, functional diversity of local fish assemblages was greater in lower reaches. The cascade of dams has impacted the distribution of functional groups of local fish assemblages of Uruguai River. The alteration of functional groups in upper reaches of the river has potential consequences for ecosystem processes and services, such as nutrient cycling and fisheries.(AU)


As barragens reduzem a conectividade longitudinal dos rios e interrompem a migração e a distribuição espacial das espécies, configurando impactos pouco estudados para alguns rios Neotropicais megadiversos. Investigamos a distribuição espacial de espécies de peixes com diferentes características tróficas e reprodutivas para avaliar como grupos funcionais responderam a uma cascata de reservatórios no rio Uruguai, sul do Brasil. Abundância de peixes, biomassa e composição de espécies foram avaliadas em oito locais ao longo do gradiente longitudinal. A assembleia de peixes no trecho superior foi caracterizada principalmente por espécies de pequeno e médio porte em níveis tróficos mais elevados, enquanto que os ambientes localizados mais a jusante apresentaram mais espécies de médio e grande porte, incluindo muitas espécies carnívoras. Espécies com alta fecundidade, migradores sazonais e bagres com fertilização interna foram comuns no curso médio e inferior. Espécies detritívoras dominaram áreas distantes das barragens. A diversidade funcional das assembleias de peixes locais foi maior nas partes inferiores. A cascata de barragens impactou a distribuição dos grupos funcionais das assembleias de peixes locais no rio Uruguai. A alteração da diversidade funcional no curso superior do rio tem consequências potenciais para a dinâmica e serviços do ecossistema, como ciclagem de nutrientes e pesca.(AU)


Subject(s)
Animals , Dams , Reproductive Techniques/veterinary , Rivers , Fishes
20.
Neotrop. ichthyol ; 19(4)2021.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1485609

ABSTRACT

ABSTRACT The genus Cichla is a highly diverse group, with 16 species already described. Externally, some species are very similar and discriminating between them may be very difficult. Nevertheless, discrimination of fish stocks is essential for management purposes. Morphometric analyses of otoliths have been successfully used to distinguish species and fish stocks, especially in marine environments. This study evaluated whether sagittal otolith shape can be used to discriminate among the species Cichla temensis, C. monoculus, and C. orinocensis, as well as within populations of C. temensis in rivers of the Amazon. Shape indices and Fourier coefficients were used to describe the shape of the otoliths. Among the groups of species, the morphology of the sagittal otolith of C. temensis was totally distinct from the species C. monoculus and C. orinocensis. While among populations of C. temensis, individuals from the Negro and Jatapú Rivers were different, regardless of the methods used. These results confirm the ability to differentiate species and populations by using the morphology of otoliths. However, more research is needed to verify the role of genetic versus environmental and biotic effects, and thus be able to explain the discrimination observed in otoliths.


RESUMO O gênero Cichla é bastante diverso, com 16 espécies descritas. Algumas espécies são externamente muito similares e sua discriminação pode ser bastante difícil. Ao mesmo tempo, a discriminação de estoques pesqueiros é essencial para propostas de manejo. Análises morfométricas em otólitos têm sido utilizadas com sucesso para a distinção de espécies e estoques pesqueiros, principalmente em ambientes marinhos. Este estudo avaliou se o formato do otólito sagittal pode ser utilizado para discriminar entre espécies Cichla temensis, C. monoculus e C. orinocensis, bem como dentro de populações de C. temensis em diferentes rios amazônicos. Índices de forma e coeficientes de Fourier foram utilizados para descrever a forma dos otólitos. Dentre as espécies, a morfologia do otólito sagittal do C. temensis mostrou ser totalmente distinta das espécies C. monoculus e C. orinocensis. Enquanto no grupo das populações de C. temensis, os indivíduos dos rios Negro e Jatapú mostraram-se diferentes independente dos métodos utilizados. Esses resultados confirmam a capacidade de diferenciação de espécies e populações através da morfologia dos otólitos. No entanto, são necessárias mais pesquisas para verificar o papel dos efeitos genéticos em comparação aos efeitos ambientais e bióticos para explicar a discriminação observada nos otólitos.

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