134 resultados para bioindicators


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This research aimed to describe the macroscopic and microscopic liver of tambaqui, Colossoma macropomum, Teleost freshwater Family Characidae, of great economic interest for the Amazon basin. We used six juveniles aged between six month and one year, from the small holding Esteio, Alta Floresta/MT, that develops mainly fish farming. The body was photographed in situ, described macroscopically, and fragments were removed and processed by routine histological techniques through paraffin embedding and HE staining. The liver, located ventrally to the swim bladder and craniodorsally to the stomach, is brownish red and consisted of three lobes, the right lateral, the left lateral and the ventral lobe. Microscopically, the parenchyma consists of hepatocytes varying from irregular rounded hexagonal to round forms with a large and central nucleus, and arranged in linear strings limited by sinusoids and radiating to central veins, but with absence of liver lobules. The central veins are distributed throughout the parenchyma, while the portal space consists in most cases only of a hepatic vein and bile duct; elsewhere exist artery and duct. Formation of portal triads was not founde. Melano macrophages were frequently seen dispersed throughout the central parenchyma. The morphofunctional study of the digestive system of fishes of the Amazon basin is important to obtain knowledge about their weight gain, large scale production for human consumption and preservation of the species, and has also its importance for being used as bioindicators today.

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The city of Sao Paulo is located in a subtropical region whose climate exhibits few defined seasons as well as frequent oscillations in temperature and rainfall throughout the year. In addition to interfering with physiological processes, these peculiar climatic dynamics influence the formation of O-3 and its influx into leaves, causing species used as bioindicators in temperate climates to be ineffective here. This study evaluated gas exchange variations in CO2 and H2O and leaf injuries induced by O-3 in Nicotiana tabacum Bel-W3 in relation to oscillations in environmental conditions. Plants were exposed to an O-3-polluted environment for fifteen periods of fourteen days each throughout 2008. Gas exchange and O-3 were higher during the summer and winter but were highly variable in all seasons. Severe injuries occurred during the winter and spring, with significant variation in this parameter being observed throughout the year. An analysis of biotic and abiotic variables revealed complex relationships among them, with great importance of meteorological factors in plant responses. We conclude that under unstable climatic conditions, the relationship between O-3 flux and injury is weak, and the qualitative character of biomonitoring is further confirmed. (c) 2012 Elsevier Ltd. All rights reserved.

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The purpose of this work was to verify the benthic macroinvertebrates community responses through environmental factors along a headwater tropical reservoir. Samplings were taken with a Van-Veen grab along the reservoir in littoral and profundal regions and in the headwater, next to the dam and the middle of the reservoir. Samples were taken during both wet and dry seasons. Dissolved oxygen concentrations, electric conductivity, temperature and pH near the sediment have been performed in situ, at every sampling station by using a multiprobe and Secchi disc. Total water phosphorus and chlorophyll a concentrations were analyzed to determine the trophic state index. Sediment's organic matter, total phosphorus, nitrogen concentrations and granulometric composition were measured. In order to verify which environmental variables would have more influence over the benthic macroinvertebrates community, a canonical correspondence analysis (CCA) was performed. The total number of recorded taxa was 28. Among them, the family Chironomidae (Diptera) was the richest group (19 taxa). It can be proposed that the benthic macroinvertebrates community may be influenced by environmental conditions such as nutrient and organic matter availability, as well as dissolved oxygen concentration. Macroinvertebrates are adequate bioindicators of water quality due to their sensibility to environmental changes mentioned before. Chironomus sp, Limnodrilus hoffmeisteri and Branchiura sowerbyi comprises a group that can be considered bio-indicators of eutrophic conditions. A second group can be considered as indicator of mesotrophic conditions. The presence of two or more members from that group which comprises Tanytarsini spp, Fissimentum sp, Pelomus sp and Goeldichironomus sp, like predominant taxa, may indicates mesotrophic conditions.

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Ocean temperatures are rising throughout the world, making it necessary to evaluate the impact of these temperature changes on sea urchins, which are well-known bioindicators. This study evaluated the effect of an increase in temperature on the immune response of the subtidal Lytechinus variegatus and the intertidal Echinometra lucunter sea urchins. Both species were exposed to 20 (control), 25 and 30 °C temperatures for 24 h, 2, 7 and 14 days. Counting of coelomocytes and assays on the phagocytic response, adhesion and spreading of coelomocytes were performed. Red and colorless sphere cells were considered biomarkers for heat stress. Moreover, a significant decrease in the phagocytic indices and a decrease in both cell adhesion and cell spreading were observed at 25 and 30 °C for L. variegatus. For E. lucunter, the only alteration observed was for the cell proportions. This report shows how different species of sea urchins respond immunologically to rising temperatures

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Programa de doctorado: Ecología y Gestión de los Recursos Vivos Marinos

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[EN] Bioindicators have been used in urban and industrial areas to control the atmospheric pollution because it constitutes one of the most important environmental problems of human health. In this sense, mosses are able to reflect the chemical composition of surrounding atmosphere that together with the easy production techniques becomes mosses as one of the potential bioindicators in Europe. This study is part of the Mossclone project (FP-7) and quantifies the adsorption of heavy metals on 4 typical moss species in order to propose one of them to be used for environmental monitoring in the moss bag technique.

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Diese Arbeit war ein Teilprojekt des Kompetenzzentrums „Flut und Hitze“ der Johannes-Gutenberg-Universität Mainz. Das gesamte Projekt beinhaltete bereits Untersuchungen über mögliche Folgen des lokalen Klimawandels (Überflutung/Trockenheit) auf andere Tiergruppen (z.B. Collembolen, Arachniden, etc.). Mit Hilfe der Laufkäfer als Bioindikatoren sollten mögliche Tendenzen des Klimawandels, aufgrund von Überflutungen, bzw. dem Ausbleiben von Überflutungen, aufgezeigt werden. In diesem Zusammenhang erfolgte die phänologische Erfassung der Laufkäfer in drei Untersuchungsgebieten entlang des Rheins: ein geschütztes Auwaldfragment und ein Polder in Ingelheim sowie ein Polder in Worms. Über einen Zeitraum von 2-3 Jahren wurde, mittels klassischer Fangmethoden (Bodenfallen), die Laufkäferfauna kontinuierlich erfasst. Insgesamt konnten im Auwald Ingelheim 2861 Individuen aus 59 Arten gefangen werden, im Polder Ingelheim 16029 Individuen aus 96 Arten und im Polder Worms 6946 Individuen aus 72 Arten. Seit 2003 wurde das Auwaldfragment nicht mehr vollüberflutet, was die geringe Anzahl an gefundenen auetypischen Arten erklärte. Die Laufkäferfauna des Auwaldes zeigte zwar noch einen deutlich feuchtegeprägten Charakter, jedoch war der Druck der einwandernden eurytopen Offenlandarten aus der Umgebung enorm. Der Polder Ingelheim wurde 2006 fertiggestellt und direkt im Anschluss beprobt. Der Polderinnenraum wurde durch den Bau eines ökologischen Flutungskanals an die Dynamik des Rheins angeschlossen. Der tiefergelegte Innenraum zeigte eine deutlich feuchteliebende Laufkäferfauna. Die trockenen höher gelegenen Randbereiche wiesen im Gegensatz dazu eine deutliche Ruderalfauna auf. Der Polder in Worms wurde bereits direkt nach seiner Fertigstellung 2001 von der Arbeitsgruppe Prof. Dr. Seitz (Universität Mainz) beprobt. Die erneute Datenerhebung 2008 sollte mögliche Veränderungen in der Laufkäferfauna sowie eine mögliche Sukzession aufzeigen. Es zeigten sich deutliche Veränderungen der Laufkäfergemeinschaften an den Standorten sowie die Ausbildung verschiedener Mikrohabitate.

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In this chapter, the impact of watershed acidification treatments on WS3 at the Fernow Experimental Forest (FEF) and at WS9 on vegetation is presented and summarized in a comprehensive way for the first time. WS7 is used as a vegetative reference basin for WS3, while untreated plots within WS9 are used as a vegetative reference for WS9. Bioindicators of acidification impacts that will be considered include several measures of tree and stand growth rates, foliar chemistry, bolewood chemistry, and herbaceous species composition and diversity. These studies enhance our understanding of the inter-relationships of changes in soil conditions caused by the acidification treatment and the condition of forest vegetation.

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Evaluar la contaminación por metales pesados en los ecosistemas permite conocer la capacidad bioindicativa de especies vegetativas. El objetivo fue determinar la concentración de metales pesados en Prosopis laevigata, Acacia spp. y Schinus molle bajo el efecto de usos suelo y temporalidad. El área se sitúa en la colindancia de los Municipios de Soledad de Graciano Sánchez y San Luis Potosí fragmentada por usos de suelo: agropecuario, comercio y servicios, residencial urbano y minero. Fueron tomadas muestras de hojas de las tres especies en las estaciones de verano, otoño, invierno y primavera y se evaluó la concentración de metales pesados a través de la técnica de ICP-MS. Los análisis estadísticos indicaron niveles de Aluminio (Al) > Cinc (Zn) > Plomo (Pb) > Cobre (Cu) > Titanio (Ti) > Vanadio (V) > Arsénico (As) > Cromo (Cr) > Cadmio (Cd) > Cobalto (Co). Los elementos Al, As, Cd, Cr, Pb y Ti presentaron niveles por encima del umbral normal en vegetación. El uso de suelo tuvo efecto significativo con Al, Ti, Cd, As y Pb; los árboles ubicados en los usos de suelo minero, comercio y servicios tuvieron la mayor concentración. La especie tuvo efecto significativo con Al y Pb siendo Acacia spp. el que presentó la mayor capacidad de acumulación. La temporada del año impactó significativamente en la acumulación de As, Cd, Co, Cu, Cr y Ti en las tres especies. La dinámica antropogénica de los diferentes usos de suelo genera partículas y residuos con metales pesados impactando en la disponibilidad y acumulación en las especies evaluadas. Se contribuye a evaluar el impacto ambiental en el sistema fragmentado recomendando dar continuidad a este tipo de estudios.

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The presented work proposes a new approach for anomaly detection. This approach is based on changes in a population of evolving agents under stress. If conditions are appropriate, changes in the population (modeled by the bioindicators) are representative of the alterations to the environment. This approach, based on an ecological view, improves functionally traditional approaches to the detection of anomalies. To verify this assertion, experiments based on Network Intrussion Detection Systems are presented. The results are compared with the behaviour of other bioinspired approaches and machine learning techniques.

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A Mata Atlântica é considerada um dos biomas mais importantes do mundo devido à sua alta biodiversidade e funções ecossistêmicas. Entretanto, encontra-se fragmentada em porções de pequenas dimensões esparsas em uma matriz predominantemente agrícola, composta principalmente por extensas pastagens e monoculturas. Desse modo, os sistemas agroflorestais por apresentarem uma estrutura diferenciada dos monocultivos e similar às condições naturais, podem ser utilizados como uma alternativa para o manejo e a conservação da biodiversidade nos remanescentes florestais. A fragmentação provoca modificações no ambiente que irão refletir na perda e no deslocamento da biodiversidade, estando os insetos entre os grupos mais afetados. Uma das formas de se avaliar o estado de conservação dos fragmentos e o impacto antrópico nos sistemas vegetacionais, é estudar a presença e distribuição de organismos bioindicadores. Dentre esses, os insetos ocupam posição de destaque. Os insetos da família Scarabaeidae e da subfamília Scolytinae são bons indicadores de distúrbios, pois são muito sensíveis ás mudanças ambientais. Neste trabalho hipotetisou-se que a presença desses insetos está relacionada com a estrutura da vegetação e as condições de vida proporcionadas pelas diferentes formas de uso-da-terra. O objetivo desta pesquisa foi avaliar a diversidade de espécies, o padrão de abundância e a similaridade entre as populações de coleópteros (Scarabaeidae e Scolytinae) em diferentes sistemas vegetacionais de diferentes estruturas: i) Fragmento de floresta estacional semidecidual dividido em três áreas: beira do rio, centro e borda; ii) Sistema Agroflorestal (SAF) (interface entre o fragmento e o pasto); iii) Pasto composto de Brachiaria decumbens (L.); iv) Monocultivo de café (Coffea arábica L.); v) Monocultivo de seringueira (Hevea brasiliensis Müell. Arg.); vi) SAF de café e seringueira - todos situados numa região de domínio anterior de floresta estacional semidecidual em Piracicaba-SP. Os sistemas foram caracterizados quanto à sua estrutura e condições micrometeorológicas. Os insetos foram coletados mensalmente entre agosto/2013 e julho/2014 utilizando-se dois tipos de armadilhas: Pitfall e etanol modelo ESALQ-84. Foram coletados 1.047 espécimes distribuídos em 21 espécies da família Scarabaeidae e 1.833 indivíduos de 38 espécies da subfamília Scolytinae. A maior quantidade de espécies de Scarabaeidae foi encontrada na borda do fragmento florestal, enquanto que a maior abundância ocorreu no fragmento florestal perto do rio. A subfamília Scolytinae apresentou a maior riqueza de espécies no sistema agroflorestal misto (borda) e a maior abundância no sistema agroflorestal café-seringueira. A abundância e riqueza de espécies da família Scarabaeidae foram correlacionadas positivamente com a temperatura do ar, temperatura e umidade do solo e a precipitação. Por outro lado, a abundância e a riqueza de espécies da subfamília Scolytinae apresentaram correlação negativa com a temperatura do ar e a temperatura e umidade do solo. Ambos os grupos de insetos apresentaram a maior abundância e riqueza de espécies nas áreas com estrutura vegetacional mais complexa, sendo influenciadas pelas condições microclimáticas dentro de cada local.

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One of the key environmental concerns about shrimp farming is the discharge of waters with high levels of nutrients and suspended solids into adjacent waterways. In this paper we synthesize the results of our multidisciplinary research linking ecological processes in intensive shrimp ponds with their downstream impacts in tidal, mangrove-lined creeks. The incorporation of process measurements and bioindicators, in addition to water quality measurements, improved our understanding of the effect of shrimp farm discharges on the ecological health of the receiving water bodies. Changes in water quality parameters were an oversimplification of the ecological effects of water discharges, and use of key measures including primary production rates, phytoplankton responses to nutrients, community shifts in zooplankton and delta(15)N ratios in marine plants have the potential to provide more integrated and robust measures. Ultimately, reduction in nutrient discharges is most likely to ensure the future sustainability of the industry. (C) 2003 Elsevier Ltd. All rights reserved.

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Globally, human populations are increasing and coastal ecosystems are becoming increasingly impacted by anthropogenic stressors. As eutrophication and exploitation of coastal resources increases, primary producer response to these drivers becomes a key indicator of ecosystem stability. Despite the importance of monitoring primary producers such as seagrasses and macroalgae, detailed studies on the response of these benthic habitat components to drivers remain relatively sparse. Utilizing a multi-faceted examination of turtle-seagrass and sea urchin-macroalgae consumer and nutrient dynamics, I elucidate the impact of these drivers in Akumal, Quintana Roo, Mexico. In Yal Ku Lagoon, macroalgae bioindicators signified high nutrient availability, which is important for further studies, but did not consistently follow published trends reflecting decreased δ 15N content with distance from suspected source. In Akumal Bay, eutrophication and grazing by turtles and fishes combine to structure patches within the seagrass beds. Grazed seagrass patches had higher structural complexity and productivity than patches continually grazed by turtles and fishes. Results from this study indicate that patch abandonment may follow giving-up density theory, the first to be recorded in the marine environment. As Diadema antillarum populations recover after their massive mortality thirty years ago, the role these echinoids will have in reducing macroalgae cover and altering ecosystem state remains to be clear. Although Diadema antillarum densities within the coral reef ecosystem were comparable to other regions within the Caribbean, the echinoid population in Akumal Bay was an insufficient driver to prevent dominance of a turf-algal-sediment (TAS) state. After a four year study, declining coral cover coupled with increased algal cover suggests that the TAS-dominated state is likely to persist over time despite echinoid recovery. Studies on macroalgal diversity and nutrients within this same region of echinoids indicated diversity and nutrient content of macroalgae increased, which may further increase the persistence of the algal-dominated state. This study provides valuable insight into the variable effects of herbivores and nutrients on primary producers within a tropical coastal ecosystem. Results from this work challenge many of the currently accepted theories on primary producer response to nutrients and herbivory while providing a framework for further studies into these dynamics.

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Many coastal wetland communities of south Florida have been cut off from freshwater sheet flow for decades and are migrating landward due to salt-water encroachment. A paleoecological study using mollusks was conducted to assess the rates and effects of salt-water encroachment due to freshwater diversion and sea level rise on coastal wetland basins in Biscayne National Park. Modem mollusk distributions taken from 226 surface sites were used to determine local habitat affinities which were applied to infer past environments from mollusk distributions found in soil cores. Mollusks species compositions were found to be strongly correlated to habitat and salinity, providing reliable predictions. Wetland soils were cored to bedrock at 36locations. Mollusks were abundant throughout the cores and 15 of the 20 most abundant taxa served as bioindicators of salinity and habitat. Historic accounts coupled with mollusk based inference models indicate (1) increasing salinity levels along the coast and encroaching into the interior with mangroves communities currently migrating westward, (2) replacement of a mixed graminoid-mangrove zone by a dense monoculture of dwarf mangroves, and (3) a confinement of freshwater and freshwater graminoid marsh to landward areas between urban developments and drainage canals.