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Fallesen, Grethe. "The ecology of macrozoobenthos in Arhus Bay, Denmark." Thesis, University of Stirling, 1994. http://hdl.handle.net/1893/21608.
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The aim of this thesis has been to: 1) assess the state of pollution in the two study areas and relate them to recent changes found in the Kattegat - Belt Sea area; 2) examine the observed spatial and temporal variability in species composition, abundance and biomass in Arhus Bay and the Formes area and relate the variability to antropogenic and natural causes; 3) discuss and assess methods, particularly for the estimation of secondary production and the use of multivariate analyses as methods for examining changes in macrozoobenthic communities. Macrozoobenthos were sampled at 15 stations in Arhus Bay, Denmark from 1985 to 1991 while data from Formes (reference area) included 55 sampling stations from 1986 to 1990. Monthly sampling took place at one station in Arhus Bay in 1990 and 1991. The two study areas are both situated on the eastcoast of Jutland in the Kattegat - Belt Sea area at 13-17 m depth and both receive waste water from long sea outfalls. Although both areas are Subjected to salinity stratification for most of the year, the exposed position of the Formes area on the open Kattegat coast prevents it from suffering from severe oxygen deficiencies, unlike the Arhus Bay which is a sheltered, semi-enclosed sedimentation area where oxygen concentrations in the bottom water can be very low. At Formes the sediment is sandy while it is silty in Arhus Bay. The spatial and temporal variability in the benthos in Arhus Bay could to a great extent be explained by the variation in 7 important species: Abra alba, Corbula gibba, Mysella bidentata, Nepthys hombergii, N. ciliata, Ophiura albida and Echinocardium cordatum. The fluctuations in the number and biomass of A. alba had a pronounced effect on the total abundance and biomass in Arhus Bay. The severe winter of 1986/87 with low temperatures and oxygen depletion under the ice cover practically eliminated A. alba from the bay. A. alba quickly recolonized the area and was found in high numbers in 1988. Studies of growth of A. alba in 1990 and 1991 showed that by the end of 1990 the population had reached an average length of 10 mm while the average shell length was only 5 mm by the end of 1991. The difference between the two years could be attributed to the difference in sedimentation of phytoplankton from the water column. As in other parts of the Kattegat - Belt Sea area, Arhus Bay has experienced low oxygen concentrations in the bottom water in late summer early autumn throughout the 1980s. Only the oxygen depletion under the ice cover in early spring 1987 and the local oxygen deficiencies south of the outlet in 1989 and 1990 actually killed parts of the benthic fauna. Apart from 1981, the oxygen deficiencies have thus been less severe in Arhus Bay than in other parts of the southern Kattegat in the 1980s. The number of species, abundance and biomass decreased at Fornres from 1980 to 1985 while the discharge of BOD was fairly constant during the same period. From 1986 there was a slight decrease in the discharge of BOD but a considerable increase in the number of species, abundance and biomass. At least for the second half of the 1980s there was no straightforward relation between the organic enrichment from the outlet and species composition, abundance and biomass and suggests that other factors are also important influencing the fluctuations in the benthic fauna. Estimates of total secondary community production were found to be very dependent on the method used. The method described by Brey (1990) was found acceptable for estimating secondary production in Arhus Bay but care should be exercised when comparisons are made with other areas where different methods have been used to estimate production. Secondary production was estimated more accurately for some of the abundant species in Arhus Bay on the basis of monthly samplings by the method described by Crisp (1984). Among the multivariate analyses the Detrended Correspondence Analysis (DCA) and nonmetric Multidimensional Scaling (MDS) proved to be the most successful with the Arhus Bay and Fornes data sets. Two Way INdicator SPecies ANalysis (TWINSPAN) did not work well with the Fornes data because it imposed discontinuities on data sets with continous variation in distribution of species among samples. As community types existed to a certain degree in Arhus Bay TWINSPAN worked well with these data. DCA and MDS were found to be useful techniques for analysing large data sets because they can summarize the data matrices to a manageable form and find possible patterns in the data sets. The results of the analyses can then be used as starting point for more detailed investigations of single species/samples or groups of species/samples. By using different transformations of the raw data the role of dominant or rare species can be assessed. A major 'problem in the assessment of multivariate techniques is the lack of external standards to compare with. The results of multivariate analyses must therefore be assessed critically on the basis of a careful examination of the species list combined with the knowledge and experience of the investigator. The methods used all had their advantages and limitations but each of the different methods added some important information to the picture of the benthic community in Arhus Bay and Fornes. It was thus an considerable advantage to use several different methods to analyse the spatial and temporal variability in the benthic fauna in relation to antropogenic and natural causes.
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Pessa, Giuseppe <1969>. "Aspetti metodologici dello studio del macrozoobenthos negli ambienti acquatici di transizione." Doctoral thesis, Università Ca' Foscari Venezia, 2005. http://hdl.handle.net/10579/680.
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Samiaji, Joko. "The ecology of a Zostera noltii bed ecosystem in the Solent." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368150.
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Roskosch, Andrea. "The influence of macrozoobenthos in lake sediments on hydrodynamic transport processes and biogeochemical impacts." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/16423.
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Ziel dieser Dissertation ist, Wissensdefizite im Bereich der Bioirrigation von Süßwassersedimenten abzubauen. Als Untersuchungsorganismus wurde Chironomus plumosus ausgewählt weil diese weit verbreitete Larve ihre U-förmigen Röhren mit Überstandswasser durchspült und so Nahrung aus dem Wasser filtriert. Um Bioirrigation in Wohnröhren mit einem Durchmesser von ca. 1,7 mm zu untersuchen, wurden geeignete Messmethoden entwickelt, mit denen für das 4. Larvenstadium die Parameter Fließgeschwindigkeit (14,9 mm/s), Pumpzeit (33 min/h) und Pumprate (61 ml/h) gemessen wurden. Bei einer Populationsdichte von 745 Larven/m2 kann somit ein Wasservolumen äquivalent zum Volumen des Müggelsee in Berlin, innerhalb von 5 Tagen durch das Sediment gepumpt werden. Die Positronen-Emissions-Tomographie wurde für die Sedimentanalytik adaptiert und der Transport im Porenwasser analysiert. Mit den Untersuchungen wure gezeigt, dass auch in schlammigen Seesedimenten ein advektiver Transport durch Bioirrigation verursacht wird, der nicht zu vernachlässigen ist. Steigende Temperaturen resultieren aufgrund steigender Fließgeschwindigkeit in einen signifikanten Anstieg der Pumprate sowie der Eintragsrate von Überstandswasser ins Sediment. Ein abfallender Sauerstoffgehalt verlängert die Pumpzeit und führt zu einer sinkenden Fließgeschwindigkeit. Außerdem wird aus den Untersuchungen eine jahreszeitliche Variabilität der Bioirrigation sichtbar, welche unabhängig von konstanten Laborbedingungen auftritt. Mit dem Wasserstrom werden Porenwasserspezies wie SRP in den Wasserkörper abtransportiert, wohingegen SO42- und O2 aus dem Überstandswasser in das Sediment eingetragen werden. Ferner kommt es zur Oxidation von Fe2+ infolgedessen Phosphat im Sediment festgelegt wird, wie mittels P-Fraktionierung gezeigt werden konnte. Mikrobiologische Untersuchungen zeigten, dass Bioirrigation die mikrobielle Abundanz steigert, die Bakteriengemeinschaft verändert und das Potential zur enzymatischen Hydrolyse erhöht.The aim of this thesis is to fill gaps of knowledge regarding bioirrigation in freshwater sediments. Chironomus plumosus was chosen for the investigations since the filter-feeding larva dwelling in U-shaped burrows is quite common and flushes its burrow with water from the overlying water body. To investigate bioirrigation activity in burrows of approximately 1.7 mm in diameter appropriate measurement techniques were developed. With the methods several parameters were measured for 4th stage of larvae: flow velocity (14.9 mm s-1), pumping time (33 min h-1), and pumping rate (61 ml h-1). Consequently, a water volume equivalent to the volume of Lake Müggelsee in Berlin is pumped through the sediment every 5 days by a population density of 745 larvae m-2. The nuclear medicine imaging technique Positron Emissions Tomography was adapted and used to analyze the transport in the sediment pore water. By means of the experiments, it could be shown that even in muddy lake sediments advection is a relevant transport process and should not be neglected. Rising temperatures result in increased pumping rates and increased influx rates of surface water into the sediment due to increased flow velocities in the burrows. Dropping oxygen concentrations prolong the pumping duration while the flow velocity decreases. Furthermore, experiments show a seasonal variability of bioirrigation which is independent of constant laboratory conditions. Pore water species such as SRP are transported with the water flow into the overlying water body, whereas SO42- and O2 are transported from the overlying water into the sediment. Due to the oxidation of Fe2+, phosphorus is fixed into the sediment, a result confirmed by P-fractionation. Microbiological investigations of the burrow walls demonstrated that the bioirrigation activity enhances the microbial abundance, changes the community structure, and increases the potential of enzymatic hydrolysis.
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Masikane, Ntuthuko Fortune. "Nearshore subtidal soft-bottom macrozoobenthic community structure in the western sector of Algoa Bay, South Africa." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1466.
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The objectives of this study were to characterise macrozoobenthic community structure of the western sector of Algoa Bay, to identify the drivers of community structure and to develop a long-term monitoring framework. Data were collected from six study sites stratified along-shore. Each site comprised three stations; most sites were located in areas directly influenced by anthropogenic activities such as inflow from storm water drains and areas where dredged spoil was dumped. Other sites included areas in close proximity to estuary mouths. Physico-chemical parameters of the water column were measured with a YSI instrument, sediment for faunal and physico-chemical analyses was sampled with a Van Veen grab, and collected macrofauna were sedated and preserved pending analysis. In the laboratory, macrofauna were identified to finest taxonomic resolution possible under dissecting and compound microscopes, and enumerated. Sediment samples for physico-chemical analyses were kept frozen pending analysis. Up to 187 species belonging to 137 genera and 105 families were identified. Univariate community parameters such as abundance and number of species varied significantly along-shore, generally increasing towards less wave-exposed sites. Multivariate analyses revealed that community assemblages were heterogeneously distributed along-shore, corresponding to areas where anthropogenic influences such as effluent discharge and commercial harbour activities prevailed. During the 2008 survey, species assemblages separated into six groups corresponding to the six sites but xvii during the 2009 survey, species assemblages separated into four groups probably due to changes in environmental parameters such as the hydrodynamic regime. In both surveys the assemblage opposite a drainage canal (Papenkuils outfall) was distinct as it was dissimilar to all other assemblages. This site was also heterogeneous over relatively small spatial scales. Important physico-chemical variables influencing community structures during the 2008 survey included bottom measurements of temperature, salinity, dissolved oxygen, coarse sand and mud. During the 2009 survey, only bottom temperature and mud content were identified as important physico-chemical variables structuring community assemblages. The principal variable was probably the hydrodynamic regime, driving community structure at a larger scale in Algoa Bay. On a localised scale, communities were probably structured by other factors such as effluent discharges, influence of estuary mouths and activities associated with the harbour. With a lack of information on keystone species (regarded as good monitoring species) in Algoa Bay, it was proposed that groups that cumulatively comprise 50–75 percent of total abundance within communities be monitored annually. Included are amphipods, polychaetes, cumaceans, ostracods, tanaids and bivalves. It was also proposed that areas opposite estuary mouths, effluent outfalls and the dredged spoil dumpsite be monitored. This routine monitoring programme should be accompanied by periodic hypothesis driven research to assess the importance of stochastic events (e.g., upwelling) on macrozoobenthic community dynamics. Keywords: macrozoobenthos, soft-bottom, community assemblages, spatial distribution patterns, environmental drivers, long-term monitoring framework.
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Vladmir, Vandenberg da Costa Carvalho Paulo. "O macrozoobentos na avaliação da qualidade ambiental de áreas estuarinas no litoral Norte de Pernambuco Brasil." Universidade Federal de Pernambuco, 2004. https://repositorio.ufpe.br/handle/123456789/974.
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Previous issue date: 2004A rápida expansão da carcinicultura em áreas costeiras tem sido associada a vários distúrbios ambientais. A principal preocupação reside na descarga de efluentes ricos em nutrientes e matéria orgânica para os estuários e seu impacto sobre a biota. Considerando a macrofauna bentônica como indicador de estresse ambiental, o presente trabalho teve como objetivo determinar o impacto do aporte de efluentes da carcinicultura no estuário do rio Botafogo (Itapissuma-PE). Foram estabelecidas 3 estações: a montante, próximo ao ponto de despejo de efluentes e a jusante, além de 3 estações-controle no rio Siri (Goiana-PE). O macrobentos foi coletado em fevereiro e junho/2003, no mediolitoral e infralitoral. Foram amostrados parâmetros indicadores de estado trófico da água e dos sedimentos, além de descritores físico-químicos e sedimentológicos. A macrofauna foi identificada e quantificada quanto à abundância, biomassa e produção relativa. A estrutura da comunidade foi estudada através de medidas univariadas (Diversidade, Equitatividade, Abundância, Riqueza), distribucionais (Curvas ABC e Distribuição dos Táxons pelas Abundâncias), multivariadas (Ordenação MDS/ANOSIM/BIOENV, Meta-Análise, Dispersão Relativa) e multimétricas (Índice Bêntico). Não foram identificadas diferenças importantes (p>0,05) entre os estuários quanto aos indicadores de impacto orgânico (clorofila-a, Ntotal, P-total, percentuais de matéria orgânica e silte-argila nos sedimentos). Entre os índices univariados, somente as elevadas riqueza e abundância do rio Botafogo o diferenciaram (p<0,05) das estações-controle. As Curvas ABC, a Distribuição dos Táxons pelas Abundâncias, o Índice Bêntico e a Meta-Análise detectaram perturbações em ambos os estuários, diferindo, entretanto quanto à intensidade ou à distribuição espaço-temporal dos diagnósticos. O MDS/ANOSIM mostrou diferenças significativas (p<0,05) entre rios. O BIOENV discriminou a matéria orgânica, pigmentos fotossintéticos e o P-total nos sedimentos, e a temperatura e a amônia na água, como os fatores que melhor explicaram as associações bióticas do rio Botafogo. No rio Siri as variáveis associadas foram a clorofila-a do sedimento e o Eh da água. O rio Siri foi invalidado como ambiente controle por apresentar evidências de distúrbios, porém de origem incerta. Apesar de não ter sido constatada simplificação na estrutura da comunidade, o rio Botafogo apresentou alterações estruturais no macrobentos características da fase inicial de enriquecimento orgânico, provavelmente, em resposta ao aporte de efluentes da carcinicultura
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Ditsche-Kuru, Petra [Verfasser]. "Influence of the surface roughness of hard substrates on the attachment of selected running water macrozoobenthos / Petra Ditsche-Kuru." Bonn : Universitäts- und Landesbibliothek Bonn, 2009. http://d-nb.info/1016099800/34.
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Sigovini, Marco <1980>. "Multiscale dynamics of zoobenthic communities and relationships with environmental factors in the Lagoon of Venice." Doctoral thesis, Università Ca' Foscari Venezia, 2011. http://hdl.handle.net/10579/1092.
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The thesis focuses on the macrozoobenthic community in the Lagoon of Venice. Main aspects investigated include: spatial and interannual variability of the community structure; the role of environmental factors in structuring benthic communities; spatial scales of variability of the community, also in relationship to variability scales of environmental factors. A three-year data set was analyzed. High interannual variability and spatial heterogeneity was verified. Multivariate structure and univariate descriptors were considerably related to environmental factors. A gradient from sea landwards in species richness and community composition was evidenced and related to the composite ecocline, mainly to seawater renewal and salinity. More complex spatial patterns were recognized. Univariate descriptors and multivariate structures follow different scales of variability. The results have implications for quality assessment of transitional ecosystems.La tesi analizza la comunità macrozoobentonica della Laguna di Venezia. Sono stati principalmente indagati: la variabilità spaziale e interannuale della struttura della comunità; il ruolo dei fattori ambientali; le scale spaziali di variabilità della comunità, in relazione alla scala di variabilità dei fattori ambientali. Il data set analizzato è relativo a tre anni. E' stata verificata un'elevata variabilità interannuale ed eterogeneità spaziale. Descrittori di struttura multivariata e univariate sono risultati notevolmente correlati ai fattori ambientali. E' stato evidenziato un gradiente da mare verso terra in merito al numero di specie e alla composizione della comunità, in relazione ad un ecocline composito, e principalmente a ricambio idrico e salinità. Sono emersi pattern spaziali più complessi. Descrittori univariati e strutture multivariate seguono diverse scale di variabilità. I risultati hanno implicazioni per la valutazione della qualità degli ecosistemi di transizione.
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Beuter, Liesa-Kristin [Verfasser]. "Risk assessment of plant protection products in stream mesocosms with special consideration of aquatic biofilm communities and macrozoobenthos / Liesa-Kristin Beuter." Gießen : Universitätsbibliothek, 2021. http://d-nb.info/1230476393/34.
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AFGHAN, DANIAL. "Comparative study of macrozoobenthic communities from different sandy beaches of Adriatic Sea with different levels of human impact." Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/299877.
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Le spiagge sabbiose sono uno dei luoghi più importanti, non solo in quanto sostengono la biodiversità fornendo habitat e cibo, ma anche aiutando il sostentamento umano fornendo opportunità socioeconomiche. La crescente pressione sulle spiagge sabbiose sta portando al degrado dell'ecosistema costiero. Per comprendere queste minacce e il loro impatto sulle comunità macrobentoniche intertidali, è stato svolto questo progetto. Inizialmente, i dati relativi a determinati impatti umani sono stati raccolti a livello globale sotto forma di una revisione sistematica per evidenziare le lacune. I dati relativi agli impatti delle perturbazioni antropiche sul Mare Adriatico sono risultati molto limitati. Le attività del progetto sono state condotte in tre fasi dove nella prima fase sono state studiate 2 spiagge per un anno con cadenza mensile. Nella seconda fase, 4 spiagge sono state studiate su base stagionale (tre volte). Nella terza fase sono state studiate 5 spiagge solo intorno alla stagione estiva per valutare l'impatto del turismo estivo. Nelle ultime 2 fasi del progetto, sono stati presi in considerazione anche i blocchi relativi al COVID-19 poiché l'uso delle spiagge era limitato. Differenze complessivamente significative sono state riscontrate tra la macrofauna appartenente a differenti taxa. Le differenze sono probabilmente legate alla differenza nel tipo di impatto in siti diversi. Complessivamente, nella maggior parte dei siti i bivalvi appartenenti principalmente a Lentidium mediterraneum sono risultati essere i taxa più dominanti nei siti colpiti. Nei siti con meno disturbi, Donax sp. è stato trovato più comunemente alludendo a una maggiore sensibilità ai disturbi umani. Il gasteropode Tritia neritea è risultato essere uno degli organismi resistenti alle perturbazioni in quanto raggiungevano il picco di abbondanza nel periodo più turistico. Inoltre, i crostacei come gli anfipodi sono stati trovati maggiormente in siti meno colpiti e/o stagioni/periodi meno colpiti, evidenziando il loro potenziale come indicatore di disturbi negli ecosistemi delle spiagge sabbiose. Sebbene, in ambiente naturale, potrebbe diventare più complesso separare un tipo di impatto su un determinato taxon da un altro, i nostri risultati possono indicare alcune informazioni riguardanti la sensibilità di un particolare taxa rispetto a un impatto specifico.Sandy beaches are one of the most important spots that is not only sustaining biodiversity by providing habitat and food but also supporting human livelihood by providing socioeconomic opportunities. The increasing pressure on sandy beaches is leading to degradation of coastal ecosystem. To understand these threats and their impacts on the intertidal macrobenthic communities, this project was designed. Initially, data regarding certain human impacts was collected globally in the form of a systematic review to highlight the gaps. The data regarding impacts of anthropogenic disturbances on Adriatic Sea was found to be very limited. The activities of the project were conducted in three phases where 2 beaches were studied for one year on monthly basis in the first phase. In the second phase, 4 beaches were studies on seasonal basis (three times). In the third phase, 5 beaches were studied only around the summer season to evaluate the impact of the summer tourism. In the later 2 phases of the project, the COVID-19 related lockdowns were taken into account as well since the use of the beaches was limited. Overall significant differences were found among the macrofauna belonging to different taxa. The differences are possibly related to the difference in the type of impacts at different sites. Overall, at most of the sites bivalves mainly belonging to Lentidium mediterraneum was found to be the most dominant taxa at impacted sites. At sites with less disturbances, Donax sp. was found more commonly hinting about its sensitivity towards human disturbances. The gastropod specifically Tritia neritea was found to be one of the resistant organisms towards disturbances since they were peaking in abundance at the most touristic period. Furthermore, the crustaceans such as amphipod were found more at less impacted sites and/or less impacted seasons/periods, highlighting their potential as an indicator of disturbances in sandy beach ecosystems. Although, in natural environment, it could become more complex to segregate one type of impacts on a certain taxon from another, yet our detailed results can indicate some information regarding the sensitivity of a particular taxa towards a particular impact.
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Dubois, Anne-Sophie. "Composition et transfert trophique de la matière organique particulaire dans le Bassin d’Arcachon." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14515/document.
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Les écosystèmes côtiers présentent une forte production biologique, soutenue par une grande diversité de sources de matière organique particulaire (autochtones : phytoplancton, microphytobenthos, phanérogames marines, macroalgues, épiphytes ; allochtones : apports continentaux), pouvant contribuer à la production secondaire. La diversité de ces sources complexifie de manière considérable le fonctionnement écologique des systèmes côtiers — e.g. cycles biogéochimiques, réseaux trophiques — et en rend sa compréhension difficile.Une étude spatio-temporelle réalisée en 2009 dans le Bassin d’Arcachon, une lagune semi-fermée qui abrite le plus grand herbier à Zostera noltii d’Europe, a été menée afin d'estimer l’origine et la composition des matières organiques particulaire en suspension (MOPS) et sédimentaire (MOS) et d'appréhender le devenir des différentes sources de matière organique dans le réseau trophique macrobenthique. Cette approche quantitative a été effectuée principalement à l’aide des rapports isotopiques et élémentaires (δ15N, δ13C et C/N) et/ ou des acides grasA l’échelle annuelle et en moyenne pour les trois stations étudiées, la MOPS est composée principalement de phytoplancton (48 ± 2%) mais aussi de matériel continental (19 ± 4%) et de microphytobenthos (16 ± 2%), les macroalgues et les phanérogames ne contribuant que peu (8 ± 1% et 5 ± 1%, respectivement). Cette composition, qui présente une saisonnalité (faible contribution du phytoplancton en hiver au profit des apports continentaux), est principalement dépendante du climat (température) et de l’hydrodynamique / hydrodynamique sédimentaire (apports continentaux, remise en suspension du sédiment). A l’échelle annuelle et en moyenne pour les six stations ayant fait l’objet du suivi annuel, la MOS est composée principalement de sources benthiques (phanérogames : 23 ± 3% ; microphytobenthos : 19 ± 1% ; macroalgues : 19 ± 5%), mais également de matériel continental (27 ± 8%) et de phytoplancton (11 ± 2%). A l’échelle de l’écosystème (étude printanière) la composition de la MOS est similaire — avec toutefois une plus forte contribution du phytoplancton, au dépend de la matière continentale. Elle est géographiquement homogène, ce que semble favoriser l’hydrodynamique du bassin d’Arcachon associée à sa faible profondeur. La principale différence spatiale apparaît entre le sédiment subtidal (faible contribution des macrophytes au profit du matériel continental) et le sédiment de l’herbier intertidal. L’étude des voies de transfert trophique de la matière organique particulaire a mis en évidence une organisation trophique complexe avec l’existence de sous-groupes au sein des déposivores d’interface et des brouteurs. A l’échelle annuelle et à l’échelle du Bassin d’Arcachon, le microphytobenthos et les phanérogames (incluant leurs épiphytes) soutiennent 90% de la production macrozoobenthique. Cette production secondaire est principalement effectuée par les déposivores (60%). Une forte bactérivorie a été mise en évidence notamment chez les déposivores et chez le suspensivore invasif Crepidula fornicata. Les bactéries représentent ainsi un intermédiaire important dans le transfert de MOP des producteurs primaires vers les consommateurs primaires. Toutefois la pression trophique qu’exercent les consommateurs primaires de la macrofaune benthique sur les producteurs primaires est relativement modeste puisque le macrozoobenthos n’absorbe que 10% de la production primaire totale du système, ce qui rend cette dernière potentiellement disponible pour d’autres compartiments biologiques. Malgré cela l’herbier à Zostera noltii représente une ressource importante pour la macrofaune benthique. Dans le contexte de sa régression, une disparition de l’herbier engendrerait une diminution de la biomasse du macrozoobenthosAbstract
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COSTA, Clarissa Moreira Coelho. "Distribuição Espacial e Temporal do Macrozoobentos de Habitats Entremarés do Canal da Raposa, Baía de São Marcos, Maranhão, Brasil." Universidade Federal do Maranhão, 2017. http://tedebc.ufma.br:8080/jspui/handle/tede/1868.
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Macrozoobenthos of different grain size intertidal habitats were sampled during wet and dry seasons on Raposa Channel, Maranhão State, Brazil. The sampling was made with a PVC corer. The benthic organisms was sieved using 1 and 0,5 mm sieves and identified under a stereoscopic microscope. There were a few dominant species despite of many rare ones. Paraonis agilis, Notomastus aberans, Capitella capitata and Odontosyllis heterofalchaeta had high densities on Raposa Channel habitats. The macrozoobenthos had higher densities during wet season, specially the deposit and suspension feeders. The deposit feeders were dominant at higher silt/clay content habitats, while the suspension feeders dominated higher sand content ones. These habitats were the most diverse. Ceratia rustica, Vitrinella filifera, Paraonis agilis, Scaphopoda indet. and Caecum sp had high contribution on dissimilarity between habitats, most expressive during dry season. Sediment humidity, organic mater content, sand, silt and clay percentages and grain selection showed that habitats were significantly differents.
Macrozoobentos de habitats entremarés de diferentes classificações granulométricas foram amostrados nos períodos chuvoso e de estiagem no Canal da Raposa, Ilha de São Luís, Maranhão, Brasil. A amostragem utilizou um cilindro de PVC e os organismos bentônicos foram submetidos à triagem em peneiras geológicas (1 e 0,5 mm de malha) e sob microscópio estereoscópico. Foram representados por poucas espécies amplamente dominantes a despeito de numerosas espécies raras. Paraonis agilis, Notomastus aberans, Capitella capitata e Odontosyllis heterofalchaeta foram as espécies de Polychaeta mais abundantes nos habitats estudados no Canal da Raposa. O macrozoobentos atingiu maiores densidades no período chuvoso, especialmente detritívoros e filtradores. Os detritívoros foram dominantes nos habitats com maiores porcentagens de silte e argila, enquanto filtradores foram dominantes nos habitats com maiores porcentagens de areia, nos quais houve maior diversidade. Ceratia rustica, Vitrinella filifera, Paraonis agilis, Scaphopoda indet. e Caecum sp foram as espécies que mais contribuíram para a dissimilaridade entre os habitats estudados, que foi maior no período de estiagem. Umidade, teor de matéria orgânica, porcentagens de areia, silte e argila e desvio padrão dos grãos mostraram diferenças significativas entre os habitats estudados no Canal da Raposa.
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Atzori, Clarissa. "Influence of port breakwaters on surrounding polychaete fauna." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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Harbours represent unique, complex and vulnerable environments from many points of view. Macrobenthic communities are important components of the harbour biota and polychaetes are the assemblage that best represents their state of well-being and can be used as indicators of environmental quality. The structure of the macrobenthic community and of the population of polychaete annelids that characterize the softbottom habitats of two ports of the Comunidad Valenciana (port of Sagunto, port of Calpe) was analysed and compared to verify the existence of a relationship between the variation in the species composition of the populations of polychaetes and the variation in the abiotic variables (granulometric classes of fine and medium sands, mud and the content of organic matter) in force in the two environments and at the two depths (2-3 m and 8-9 m). Sampling took place on 19 May in Sagunto and 20 May 2021 in Calpe and 24 replicates were obtained for each site: 12 for each depth interval (6 were necessary for the taxonomic study and 6 for the others analysis). The analysis of the polychaete fauna carried out in the sediment samples of the port of Sagunto made it possible to identify 303 individuals distributed in 76 taxa among 26 families, while those carried out for the port of Calpe allowed to identify 221 individuals distributed in 52 taxa between 17 families. The communities of the two ports differ in terms of abundance of individuals, species composition and presence / absence of Phyla Plantae, Sipuncula, Bryozoa, Chordata. All the abiotic variables above together with the depth had influenced the structure of the communities and polychaete assemblages, as demonstrated by the correlation existing between them. These last were characterized by low specific richness, diversity and a majority of species with low abundances that can be attributed to anthropogenic stress, especially pollution and / or other environmental stress factors, which act synergistically or not.
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Roskosch, Andrea [Verfasser], Gunnar [Akademischer Betreuer] Nützmann, Dagmar [Akademischer Betreuer] Haase, and Volker [Akademischer Betreuer] Hass. "The influence of macrozoobenthos in lake sediments on hydrodynamic transport processes and biogeochemical impacts / Andrea Roskosch. Gutachter: Gunnar Nützmann ; Dagmar Haase ; Volker Hass." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://d-nb.info/1018232508/34.
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Rolemberg, Karine Fernandes. "Macrozoobentos em viveiros de engorda de camarão marinho Litopenaeus vannamei (boone, 1931) (crustacea, decapoda, penaidae) no estuário dorio Jaguaribe, Ceará, Brasil." reponame:Repositório Institucional da UFC, 2009. http://www.repositorio.ufc.br/handle/riufc/11421.
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ROLEMBERG, K. F. Macrozoobentos em viveiros de engorda de camarão marinho Litopenaeus vannamei (boone, 1931) (crustacea, decapoda, penaidae) no estuário dorio Jaguaribe, Ceará, Brasil. 2009. 85 f. Dissertação (mestrado em Ciências Marinhas Tropicais) - Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, 2009.Submitted by Nadsa Cid (nadsa@ufc.br) on 2015-04-16T15:10:10Z No. of bitstreams: 1 2009_dis_kfrolemberg.pdf: 4481167 bytes, checksum: 750c8d9d2b000e92c450f327da8b2de1 (MD5)
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The aim of this study was to characterize the benthic macrofauna of the cultivation farm of shrimps from the species Litopenaeus vannamei before the settlement and fishing, as well as to observe the effect of the shrimp predation on the macrofauna through an exclusion experiment. In order to characterize the macrofauna, samples from the supplying, middle and draining areas had been collected from the shrimp farms with five different duplicates for each area in the two moments of the cultivation. To evaluate the predation effect, gathering from the inside and outside of twenty-seven cages in a shrimp farm during the cultivation cycle had been carried through. The gathering of the organisms from the bottom of the shrimp farms as well as from the interior of the cages had been carried through with a PVC 15cm of diameter. The cages had an area of 25cm ² and 12cm of height and mesh of 3mm of opening, being covered with a screen of 0,1mm during the first days of experiment in order to block the insertion of any predator. The polychaeta presented the highest medium density, being the species Capitella sp. the most abundant. The organisms had had greater densities in the gathering that occured before the settlement, moment when it did not have shrimps in the interior of the farms. The area with the highest medium density in the shrimp farms was the supplying. In the exclusion experiment, it was observed that the medium densities in the interior of the cages had been higher than in the areas outside the cages that were subjected to the predation of shrimp. This fact proves the importance of the Benthic macrofauna in the diet of these crustaceans, since the shrimp uses it as a natural food source. It was also possible to realize that the Benthic macrofauna suffered some alterations in its community in the presence and absence of the shrimps, because some species had started to dominate the environment whereas others were extinguished. Beyond the predatory pressure of the shrimps, this fact can have been also caused for the existence of biological interactions between the species of the macrofauna that can have occurred inside and outside of the cages, prevailing the Capitella sp., that seems to have been the most successful under the conditions of the experiment.
O objetivo deste trabalho foi caracterizar a macrofauna bentônica de viveiros de cultivo de camarões da espécie Litopenaeus vannamei antes do povoamento e antes da despesca, como também observar o efeito da predação dos camarões sobre a macrofauna através de um experimento de exclusão. Para a caracterização da macrofauna, foram coletadas amostras em áreas de abastecimento, meio e drenagem dos viveiros com cinco réplicas para cada área noS dois momentos do cultivo. Para avaliar o efeito da predação, foram realizadas coletas dentro e fora de vinte e sete gaiolas em um viveiro de camarão durante o ciclo de cultivo . As coletas dos organismos no fundo dos viveiros e no interior das gaiolas foram realizadas com um coletor de PVC de 15cm de diâmetro. As gaiolas de exclusão tinham uma área de 25cm² e 12cm de altura e malha de 3mm de abertura, sendo cobertas com uma tela de 0,1mm nos primeiros dias de experimento. Os poliquetas apresentaram a maior densidade média, sendo a espécie Capitella sp. a mais abundante. Os organismos tiveram maiores densidades na coleta antes do povoamento. A área de maior densidade média nos viveiros foi o abastecimento. No experimento de exclusão, foi observado que as densidades médias no interior das gaiolas foram mais elevadas do que nas áreas fora das gaiolas. Este fato comprova a importância da macrofauna bentônica na dieta destes crustáceos, já que o camarão a utiliza como fonte de alimento natural. Foi possível perceber também que a macrofauna bentônica sofreu algumas alterações na estrutura das comunidades na presença e ausência dos camarões, dado que algumas espécies passaram a dominar o ambiente enquanto outras desapareceram. Além da pressão predatória dos camarões, este fato pode ter sido causado também pela existência de interações biológicas entre as espécies da macrofauna que podem ter ocorrido dentro e fora das gaiolas, prevalecendo a Capitella sp., que parece ter sido a mais bem sucedida sob as condições do experimento.
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Jaklin, Sandra [Verfasser], and Wolf E. [Akademischer Betreuer] Arntz. "Recruitment dynamics of North Sea macrozoobenthos in intertidal soft bottoms: larval availability, settlement and dispersal / Sandra Jaklin. Gutachter: Wolf E. Arntz. Betreuer: Wolf E. Arntz." Bremen : Staats- und Universitätsbibliothek Bremen, 2003. http://d-nb.info/1072563657/34.
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Garuti, Andrea. "Spatio-temporal diversity of Megistozoobenthos in the Antalya Gulf and relationships with environmental features." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9626/.
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Antalya Gulf is situated in the Levantine Sea, the second biggest and most eastern basin in the Mediterranean Sea. This area is an ultra-oligotrophic basin, strongly affected by anthropogenic inputs, in particular in the fishing areas. For this characteristic, in the Levantine Sea, there is a strong pressure on the natural resources and benthic assemblages. Furthermore, many alien species enter from Suez Canal and are well established in the area. All these pressures are leading to a degradation of the Levantine Sea. For this reason it is important to have tools to study and monitoring the functioning of the marine ecosystem. Benthic organisms are superior to many other biological groups for their response to environmental stresses. The variability of benthic assemblages on a site can reflect, in an integrative mode, the entire functioning of the marine ecosystem. In this study, that wants to analyze the spatial and temporal distribution of the benthic macrofaunal assemblages of Antalya Gulf, 90 benthic species divided in 8 taxa (Annelida, Cnidaria, Echinodermata, Echiura, Mollusca, Porifera, Sipunculida and Tunicata) were found. All the analyses conducted on the entire benthic class and later on Mollusca and Echinodermata separately highlighted the importance of depth on structuring benthic community.
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Schroeder, Alexander. "Community dynamics and development of soft bottom macrozoobenthos in the German Bight (North Sea) 1969 - 2000 = Dynamik und Entwicklung makrozoobenthischer Weichbodengemeinschaften in der Deutschen Bucht (Nordsee) 1969 - 2000 /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 2005. http://www.gbv.de/dms/bs/toc/477233201.pdf.
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Jasiūnas, Dovydas. "Makrozoobentoso įvairovė ir vandens kokybės įvertinimas pagal jį Mūšos upėje, Pasvalio rajone." Bachelor's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140716_111002-35198.
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Bakalauro darbo tikslas – pasirinktose Mūšos upės vietose nustatyti makrozoobentosinių organizmų grupes ir pagal juos įvertinti upės vandens kokybę. Uždaviniai – atlikus išsamią literatūros analizę, motyvuotai pasirinkti esamą arba sukurti tyrimų metodiką; pasirinktose Mūšos upės vietose surinkti ir apibūdinti makrozoobentosinius organizmus ir pagal gautus rezultatus nustatyti vandens kokybę skirtingose upės vietose; gautus biologinių tyrimų rezultatus palyginti su anksčiau atliktų vandens kokybės tyrimų rezultatais.
Darbo objektas – Mūšos upė įtekant ir ištekant iš Pasvalio rajono. Makrozoobentosiniai organizmai rinkti 2013 metų rugpjūčio 21–22 dienomis.
Tyrimo metodika pagrįsta LAND 57–2003 dokumente pateikiama Danijos upių faunos indekso (DUFI) metodu pagal Friberg'ą ir BMWP balų metodu. Makrozoobentosiniai organizmai buvo renkami renkamojo metodo principu.
Gauti rezultatai rodo, kad ties įtekėjimu į Pasvalio rajoną Mūšos upės vandens kokybė, vertinant pagal makrozoobentosą, taikant DUFI metodą priskiriama vidutinei vandens kokybės klasei (pagal BMWP – geros kokybės), nes tyrimais nustatyta, kad čia vyrauja III klasės fauna (pagal BMWP – II klasės fauna). Ties ištekėjimu iš Pasvalio rajono Mūšos upės vandens kokybė, vertinant pagal makrozoobentosą, taikant DUFI priskiriama blogos vandens kokybės klasei (pagal BMWP – vidutinės), nes tyrimais nustatyta, kad čia vyrauja IV klasės fauna (pagal BMWP – III klasės fauna).
Palyginus gautus rezultatus su ankstesnių tyrimų... [toliau žr. visą tekstą]The aim of the Bachelor’s thesis is to identify individual groups of macrozoobenthos in the selected spots of the Mūša River and to assess the river water quality on the given basis. The objectives are as follows: a motivated selection of the existing methods of research or creation of new ones following a detailed analysis of the literature; macrozoobenthos collection in the selected spots of the river and the description of organisms collected and determining the quality of water in different locations by the results; comparison of the biological results with the findings from previous water quality studies. The subject of the thesis is the Mūša River flowing into and out of Pasvalys district. Macrozoobenthos organisms were collect 21 to 22 August 2013. The research methods were based on the Danish Stream Fauna Index (DSFI) by Friberg laid down in the document LAND 57-2003 and BMWP scoring method. Macrozoobenthos organisms were collected using the method of the elective principle. The findings show that at the inflow to Pasvalys District, the water quality in the Mūša River can be classified as the average water quality in terms of macrozoobenthos by DSFI (as good water quality by BMWP), as the study found the prevalence of class III fauna (Class II fauna by BMWP). At the outflow from Pasvalys District, the water quality in the Mūša River can be classified as the poor water quality in terms of macrozoobenthos by DSFI (as average water quality by BMWP), as the study found... [to full text]
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PLUCHINOTTA, Angela. "Struttura della comunità macrobentonica in torrenti alpini: una "naturale" risposta ecologica al riscaldamento climatico." Doctoral thesis, Università degli studi di Ferrara, 2012. http://hdl.handle.net/11392/2389457.
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The predominant influence of physico-chemical conditions on community structure in terms of abundance, species richness and diversity of macroinvertebrate assemblages in headwater streams is well documented in literature, but its implications on body size distribution has been not yet considered. Organism size is one of the key determinants of community structure, and how biomass is partitioned among the biota may determine the efficiency of relevant ecological processes. Understanding how the distribution of biomass is linked to abiotic conditions we could predict the effects of environmental changes on aquatic ecosystem processes, particularly in the case of a community with a relative poor composition and with simplified food web structure, like it is present in alpine freshwater systems.
For these reasons, we compared the taxonomic structure and individual size distribution of macroinvertebrate assemblages of three Alpine streams presented similar geomorphology, water chemistry, and food chain structure, but different water thermal regimes, mainly influenced by different types of water source. Therefore, temperature was the only significant independent factor that influenced each scenario, and the relation of this variable to biological responses could be measured directly.
Our results show that hydromorfological parameters, physico-chemical characteristics and biotic factors explain much of the variability of macroinvertebrate taxonomical structural attributes, but they do not influence body size where the low temperatures have been detected as the main limiting factor. Temperature acts as a key-driver controlling taxonomical structure and invertebrate body size distribution. In agreement with previous findings, higher values of abundance and species richness correspond to warmer temperatures, as well as shifts of biomass distribution towards smaller size classes.
Observed patterns underline the relevance of possible implications of global warming on the robustness and functioning (e.g. increase of productivity, functional shift in the food-webs) of high-altitude and high-latitude sensitive ecosystems, such as Alpine headwater streams.
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ATZORI, GIULIA. "La comunità macrozoobentonica come strumento per la valutazione dello stato di qualità ecologico in ambienti di transizione: il caso della laguna di Santa Gilla." Doctoral thesis, Università degli Studi di Cagliari, 2015. http://hdl.handle.net/11584/266567.
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Transitional habitats are vulnerable ecosystems, affected by strong and unpredictable environmental parameters and exposed to several threats, both natural and anthropic, that can deeply interfere with the biological components critical to their functionality (Lardicci et al., 1993; Fraschetti, 1996; Giangrande & Mistri et al., 2000; Lardicci et al., 2001,).
The conservation and management of these habitats require an integrated study of three aspects: chemical, physical and biological (Gibson et al., 2000).
Recent directives, specifically Water Framework Directive 60/2000/EC and Marine Strategy Framework Directive 56/2008/EC, suggest that biological elements are essential tools to evaluate the quality of coastal and transitional ecosystems. In particular, the macrozoobenthic component is often employed in transitional environmental programs (Blanchet et al., 2008).
The location analyzed in this study is one of the most important wetlands in Sardinia. Despite this, there is no complete and recent information about the benthic community.
The main aim of this study is to characterize the Santa Gilla lagoon, studying some abiotic aspects (granulometry, mineralogy, heavy metals and organic matter in sediments, and salinity, pH, dissolved oxygen and temperature of the water column) and providing information about the macrozoobenthic community in relation to spatial-temporal variations, creating the research foundation for the development of an appropriate resource management and conservation strategy.
A total of 16910 organisms were found, belonging to 114 different taxa.
The distribution of these organisms in relation to the abiotic parameters was studied. Multivariate analysis highlighted two main groups, originating from distinct areas of the lagoon and influenced by different factors.
However, it is difficult to determine which variable most strongly influences the distribution of the community. Indeed, benthic organisms are expected to respond to a more complex set of environmental factors related to the water column, sediment, interstitial water, and interface layer (e.g. Maurer et al., 1985; Whiteman et al., 1996).
Different biotic indices were applied and their effectiveness was evaluated. The results were varied, but all measurement indices concluded that best ecological quality measured was in close proximity to the sea.
Through this project, important information necessary for future integrated ecosystem management was gathered. Undoubtedly, the analysis of the macrozoobenthic community is a prerequisite for the evaluation and management of ecosystems in a sustainable and appropriate manner (Ludovisi et al., 2013).
Thus, this study constitutes the starting point for future quality status assessments, as well as the basis for subsequent analysis and monitoring.
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Vanhuysse, Charles. "Impacts de l'ostréiculture à mésoéchelle sur le microphytobenthos et ses performances photosynthétiques, la macrofaune benthique et rôle de l'érosion estuarienne dans les mortalités de naissains d'huitres Crassostrea gigas liées à OsHV-1 μ Var Drivers of epipelic mictophytobenthic photobiology and groth in oyster farm Benthic macrofaunal changes in oyster parks during an OsHV-1 µVar oyster spat mortality outbreak Environmental dynamics of the Ostreid herpes virus (OsHV-1 µVar) in oyster spats and microphytobenthic biofilms during an in situ mortality outbreak In situ resuspension of benthic sediments and biofilm components during an OsHV-1 µVar Crassostrea gigas oyster spat mortality episode." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC262.
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Depuis 2008, la mortalité des naissains d'huîtres Pacifique Crassostrea gigas est principalement liée au virus de l’ostreid herpesvirus 1 µvariant (OsHV-1 µVar). Les paramètres environnementaux favorisant la persistance et la diffusion du virus pourraient jouer sur sa dynamique de propagation. Les objectifs de cette thèse étaient d’étudier in situ les interactions entre les naissains d’huîtres et leur environnement benthique lors d’un épisode de surmortalité. La photobiologie du microphytobenthos sous les tables semblait en meilleur état comparé à celle observée dans les allées pouvant favoriser la résilience virale. Les tables à huîtres atténuaient la lumière, la température et la dessication évitant ainsi une thermo et photoinhibition du microphytobenthos. Les indices de la qualité environnementale de l’habitat benthique basés sur la communauté macrozoobenthique ont traduit une dégradation du milieu suite aux apports de matière organique induits par les mortalités de naissains d’huîtres puis des échouages des macroalgues. Une quantité importante d’OsHV-1 était retrouvée à la surface du biofilm avant les mortalités. Sa remise en suspension était préférentiellement associée aux particules microphytobenthiques avec de faibles courantsSince 2008, the mortality of Pacific oyster spat Crassostrea gigas has mainly been linked to the Ostreid herpesvirus 1 μvariant (OsHV-1 μVar). Environmental parameters favoring the persistence and spread of the virus could affect its propagation dynamics. The objectives of this thesis were to study in situ the interactions between oyster spat and their benthic environment during an episode of mortality. The photobiology of the microphytobenthos beneath the tables seemed to be in a better state compared to that observed in aisles that could promote viral resilience. The oyster tables attenuated light, temperature and desiccation, thus avoiding thermo and photoinhibition of the microphytobenthos. The benthic habitat environmental quality indices based on the macrozoobenthic community showed a degradation of the environment following the influx of organic matter induced by oyster spat mortalities and strandings of the macroalgae. A significant amount of OsHV-1 was found on the surface of the biofilm before the mortalities. Resuspension was preferentially associated with microphytobenthic particles with small currents
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Fersi, Abir. "Les communautés macrozoobenthiques des chenaux de marée du golfe de Gabès." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC246.
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Ce mémoire repose sur la description qualitative et quantitative, spatiale et temporelle des communautés macrozoobenthiques des chenaux de marée du golfe de Gabès. Le benthos a été étudié dans 26 stations et au cours de quatre saisons de mars 2016 à janvier 2017. Ceci a conduit à l'identification de 23506 individus appartenant à 311 espèces de la macrofaune benthique. Ces espèces se répartissent en 4 principaux groupes zoologiques. Parmi eux les polychétes dominent en nombre d’espèces (127) et en nombre d’individus (12077).Cette liste d’espèces d’invertébrés a permis de signaler de nouvelles pour la Tunisie et même pour la science : addition de cinq nouvelles espèces d’amphipodes, une nouvelle espèce de mollusque, cinq Tanaidacés dont une nouvelle espèce Apseudopsis gabesi Esquete 2019 et Sept nouvelles espèces de polychètes. La richesse et l'abondance des espèces sont plus élevées en hiver que pendant les autres saisons pour les quatre chenaux de marée. La faune est dominée par un petit nombre d’espèces caractéristiques des zones d’accumulation de détritus et de prairies d’herbiers. La structure du benthos est liée à la localisation des chenaux de marée dans le golfe de Gabès. Les abondances sont faibles dans le chenal de Kerkennah par rapport aux autres chenaux, notamment le chenal Maltine, avec une accumulation élevée de matière organique en hiver. Il y a aussi des faibles abondances dans les zones d’hydrodynamiques à haute énergie avec des sédiments graviers ; inversement, la présence de macrophytes augmente la diversité du macrozoobenthos. Les valeurs les plus élevées en matière organique totale se situent dans les sédiments les plus vaseux. Le type de sédiment varie d’un chenal à l’autre selon la localisation et les caractéristiques de chaque chenal et les sédiments de toutes les stations d’étude ne sont pas contaminés sauf ceux de la station CML1 qui présentent une contamination en Pb. Les sédiments sont plutôt des sables ce qui n’est pas favorable à la fixation des polluants (fixés plutôt sur les minéraux argileux, la matière organique, les oxydes, les sulfures qui appartiennent plutôt aux fractions fines et que l’on retrouvera dans les vases). Chaque chenal présente un assemblage faunistique original dominé soit par des polychètes, des amphipodes, des tanaidacés ou des mollusquesThis study is based on the qualitative and quantitative, spatial and temporal description of the macrozoobenthic communities of the tidal channels of the Gulf of Gabes. Benthos was analyzed over 26 stations and during four seasons from March 2016 to January 2017. Results show the identification of a total of 23 506 individuals representing 311 species of benthic macrofauna. These species are divided into four main zoological groups. Polychetes dominate the assemblage with about 127 species and a total number of 12 077 individuals.This inedit assemblage of invertebrates represents an exceptional and unique record in Tunisia and in the world marine science: we added five new species of amphipods, a new species of molluscs, five Tanaidaceae including a new species Apseudopsis gabesi Esquete 2019 and seven new species of polychaetes. Species diversity and abundance are higher in winter than in other seasons over all tidal channels. Fauna assemblage is dominated by a small number of species characteristic of the areas of accumulation of detritus material and herbaceous zones. The structure of the benthos is related to the location of tidal channels in the Gulf of Gabes. Abundances are low in the Kerkennah Channel compared to other channels, including the Maltine Channel, with a high accumulation of organic matter during winter. There are also low abundances in high energy hydrodynamic zones with gravel sediments; conversely, the presence of macrophytes increases the diversity of macrozoobenthos. The highest values for total organic matter are found in muddy sediments. The type of sediment varies from one channel to another depending on the location and characteristics of each one and the type of sediments. Overall studied stations are not contaminated except those of the CML1 station which have Pb contamination. . Most of sediments are sandy that is not favorable to the fixing of pollutants (fixed rather on the clay minerals, the organic matter, the oxides, the sulphides which belong rather to the fine fractions and which one found in the mudflates). Each channel presents an original faunistic assemblage dominated by polychaetes, amphipods, tanaidaceans or molluscs
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Vanden, Bossche Jean-Pierre. "Typologie et qualité biologique du réseau hydrographique de Wallonie basées sur les assemblages des macroinvertébrés." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210955.
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Typologie des cours d’eau en Wallonie et caractérisation par la faune invertébrée
Vingt-cinq types de cours d’eau ont été définis en Wallonie d’après les termes de la Directive Cadre pour l’Eau en tenant compte des facteurs obligatoires et optionnels rassemblés sous trois critères :la taille (du « ruisseau » à la « très grande rivière »), la pente (faible, moyenne et forte), et cinq régions naturelles (la région limoneuse, le Condroz, la Famenne, l’Ardenne et la Lorraine belge, résumant les facteurs obligatoires altitude, latitude, longitude et géologie). Une approche par analyses multivariées appliquées à un grand nombre d’échantillons (listes taxonomiques) a permis de définir de façon plus précise certains types de rivières et de distinguer sept groupes typologiques montrant des assemblages faunistiques similaires.
Conditions de référence types et définition de l’état écologique des rivières en Wallonie à l’aide de métriques biocénotiques basées sur les invertébrés
Les listes faunistiques et les valeurs métriques de l’IBGN (Indice biologique global normalisé) issues du réseau d’évaluation de la qualité biologique en Wallonie ont été utilisées pour discriminer les types de rivières et pour définir les sites de référence, les conditions de référence et les limites des classes des états écologiques. Au sud du sillon Sambre et Meuse, impliquant quatre groupes typologiques de rivières, les valeurs de référence et la définition des états écologiques ont été basées et calculées sur un réseau de référence de sites de très bon état. Les « valeurs de conditions de référence » ont été définies par les médianes des métriques des sites de « très bon état ». Lorsque aucun site de très bon état n’était disponible, c’est-à-dire pour les groupes typologiques au nord du sillon Sambre et Meuse et pour la Meuse et la Sambre, les conditions de référence (ou le « potentiel écologique maximal ») et les limites de classes ont été basées sur des coefficients appliqués aux sites de « bon état » et sur jugement d’expert.
Exercice pilote d’inter-étalonnage
Cinquante échantillons ont été sélectionnés parmi les rivières du type d’inter-étalonnage européen R-C3 (petite taille, altitude moyenne, substrat siliceux) en Wallonie (correspondant aux « ruisseaux ardennais ») dans toute la gamme de qualités écologiques, du « très bon » au « mauvais » état. Chaque métrique de l’indice « Intercalibration Common Metrics » (ICM) a été comparée (par régression linéaire et polynomiale) aux valeurs de l’IBGN. La plus forte corrélation a été établie avec l’indice synthétique de l’ICM dont le R² très élevé (0,95) permet un inter-étalonnage précis et fiable. A un EQR (Equivalent Quality Ratio) de l’IBGN = 1 correspond un indice ICM très proche (= 1,004). En conséquence, la métrique « cote de l’IBGN » est proposée comme métrique pour l’évaluation de l’état écologique de la faune invertébrée en Wallonie.
Espèces exotiques et invasives
L’ouverture récente du canal à grand gabarit Main – Danube en 1992 et la navigation qui en résulte a permis à plusieurs espèces de macroinvertébrés ponto-caspiennes d’envahir successivement les bassins du Rhin et de la Meuse. De 1998 à 2000, le réseau de mesure a enregistré quatre nouvelles espèces exotiques dans la Meuse en Belgique :une polychète (Hypania invalida) et trois crustacés (Hemimysis anomala, Dikerogammarus villosus, D. haemobaphes). Peu avant, en 1995, le bivalve asiatique Corbicula fluminea et l’amphipode nord-américain Crangonyx pseudogracilis ont également été enregistrés pour la première fois. La dynamique des invasions a été étudiée et discutée.
L’état biologique actuel (2000-2002) des masses d’eaux de surface en Wallonie et l’évolution des états biologiques sur une décennie (1990-2002) figurent dans l’étude et sont discutés. Une amélioration globale de la qualité de 6 % est enregistrée pour cette période. L’amélioration de la qualité se manifeste principalement pour les états « mauvais » et « médiocre » s’élevant à l’état « moyen ».
Abstract
River typology in Wallonia and invertebrate fauna characterization
Twenty-five river-types in Wallonia were defined according to the Water Framework Directive taking into account obligatory and optional factors gathered in three criteria: the size (from “brook” to “very large river”), the slope (gentle, medium and strong) and five natural regions (Loess, Condroz, Famenne, Arden and Jurassic summarising the obligatory altitude, latitude, longitude and geology factors). A multivariate approach applied to a large amount of samples (i.e. taxa lists) led to give a more accurate definition of some river-types and to discriminate seven river-type groups exhibiting similar faunal assemblages.
Type-specific reference conditions and ecological status definition of rivers in Wallonia using invertebrate biocenotic metrics
Faunal lists and IBGN (i.e. "Standardized Global Biological Index IBGN") metric values, evolving from the biological quality assessment network in Wallonia, were used to discriminate the river types and to define the reference sites, the reference conditions and the status class limits. South of the axis made by the Sambre & Meuse Rivers, involving four river-type groups, reference values and ecological status definition were based and calculated on a reference network of sites of high status. The "reference condition values” were defined as the median values of the metrics in all “high status” sites. Where no site of high status was available, i.e. in the others river-type groups north of the same axis and in the Rivers Sambre and Meuse themselves, reference conditions (or maximum ecological potential) and class limits were based on coefficients applied to “good status” sites and on expert judgement.
Intercalibration pilot exercise
Fifty samples were selected from R-C3 rivers (i.e. small, mid-altitude, siliceous) in Wallonia (corresponding to the “Arden’s brooks”) showing the widest range of ecological quality from high to bad status. Each Intercalibration Common Metric (ICM) was compared (linear and polynomial regression) to IBGN scores. The highest correlation was found with the synthetic ICM index, whose high R² (0.95) allows accurate and reliable intercalibration. To IBGN EQR (i.e. Equivalent Quality Ratio) = 1 corresponds a very close ICM index value (= 1.004). Consequently, the metric IBGN score is being proposed to act as the metric for the assessment of the invertebrate fauna ecological status in Wallonia, Belgium.
Exotic and invasive species
The recent opening of the canal Danube – Main in 1992 and the subsequent navigation allowed several Ponto-Caspian macroinvertebrate species to invade successively the Rhine and the River Meuse basins. From 1998 to 2000, the monitoring network recorded four new alien species in the River Meuse in Belgium: one Polychaeta (Hypania invalida) and three Crustacea (Hemimysis anomala, Dikerogammarus villosus, D. haemobaphes). Earlier, in 1995, the Asian Bivalvia Corbicula fluminea and the North American Amphipod Crangonyx pseudogracilis were also recorded for the first time. The invasions’ dynamics were studied and discussed.
Present biological status (2000-2002) of surface water-bodies in Wallonia and biological status evolution over a one-decade period (1990-2002) is included and discussed in the study. A global quality improvement of 6 % is recorded for the period. Quality improvement concerns mainly the “bad” and “poor” status raising up to “moderate” status.
Doctorat en sciences, Spécialisation biologie animale
info:eu-repo/semantics/nonPublished
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KLOUDOVÁ, Jana. "Macrozoobenthos Pohořského a Dobechovského potoka v Novohradských horách." Master's thesis, 2008. http://www.nusl.cz/ntk/nusl-47284.
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The presented thesis deals with the structure and composition of macrozoobenthos of Pohořský and Dobechovský brooks in the Novohradské Mountains. The evaluation was based on the collections from 10 localities carried out in July 2001, March 2002 and July 2002/2003. In addition to determination and classification of the species found, the collections have also been qualitatively evaluated with the use of the diversity index (saprobic index, Belgian Biotic index) and the similarity index. It has been found that the zoobenthos population of Pohořský and Dobechovský brooks encompasses the species of both trout and grayling zones. In most taxa it concerns characteristic representatives of clear, flowing and adequately aerated water. Mutual species similarity of macrozoobenthos population of Pohořský and Dobechovský brooks is approximately 40%. The comparison of macrozoobenthos population diversity indices of Pohořský and Dobechovský brooks has shown that the Pohořský brook bentic fauna is, according to the obtained data, richer and better balanced. From the saprobity point of view, the Pohořský brook can mainly be placed into oligosaprobic stream class. The water of Dobechovský brook oscillates between oligosaprobic and {$\beta$}-mesosaprobic level.
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Costa, Antónia Juliana Pais. "The rocky shore macrozoobenthic communities of Buarcos bay." Master's thesis, 2011. http://hdl.handle.net/10316/18838.
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Dissertação de mestrado em Biologia, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraThe coastal areas have historically played a crucial role in human life. A large proportion of the human population inhabits coastal areas, and human density is expected to increase in the coming years. Consequently, coastal ecosystems are particularly exposed to human pressures, and some of them are among the most disturbed ecosystems of the biosphere. In rocky shores, as well as in other coastal ecosystems, benthic communities show spatially heterogeneous distributions and experience seasonal variations due to both natural and anthropogenic stresses. The major goal of this study was to assess the existence of a disturbance gradient regarding the spatial distribution of the intertidal macrozoobenthic communities of hard substrata, across the horizontal axis of three rocky platforms, and zones within and across platforms, in Buarcos bay during spring 2009. For this purpose, physcochemical parameters and macroalgae taxa were utilized in the assessment to confirm sampling was performed inside a disturbance gradient, and to compare with results obtained for the macrofauna. The behaviour of ecological indices calculated from macroinvertebrate data were compared with results obtained with the ecological tool MarMAT – Marine Macroalgae Assessment Tool. During the survey, a total of 27930 macroinvertebrate individuals corresponding to 122 different taxa were found, belonging to Phyla Annelida (44), Arthropoda (41), Cnidaria (1), Echinodermata (2), Mollusca (31), Nematoda (1), Nemertea (1) and Sipuncula (1). The species Mytilus galloprovincialis (mean density of 14345.4 ind m-2) and Chthamalus montagui (mean density of 12870.4 ind m-2) were dominant in the assemblages, accounting for 39.94% and 35.83% of the total individuals, respectively, while the remaining taxa represented individually less than 6%. The various statistical and ordination tools allowed the verification of a disturbance gradient from St A, the most proximate platform from the point source pollution, to St C, the furthermost platform. The gradient was also found from zone a (upper shore) to zone c (lower shore) within the two immediate platforms, and across platforms. Furthermore, St C and zone c, the outermost sampling areas, were found to show the highest similarities (43.14% and 48.47%, respectively) with Mytilus galloprovincialis contributing mostly to these similarities. The ecological indicators captured the differences in the communities between platforms and zones, and confirmed that disturbance gradient. The indices results were in compliance to the results obtained with the MarMAT, which according to the EQRs indicated the St A was the platform with worse ecological condition, whereas St C was the platform showing the best ecological condition. This survey contributed for a better knowledge on the rocky shore intertidal communities, aiming at improving decisions with regard to further management routines.
As áreas costeiras têm desempenhado historicamente um papel crucial na vida humana. Uma grande proporção da população humana habita em áreas costeiras, e espera-se que a sua densidade aumente nos próximos anos. Consequentemente, os ecossistemas costeiros estão particularmente expostos a pressões humanas, e alguns deles estão entre os mais perturbados ecossistemas da biosfera. Nas costas rochosas, e também em outros ecossistemas costeiros, as comunidades bentónicas apresentam distribuições espaciais heterogéneas e experienciam variações sazonais devidas a pressões naturais e antropogénicas. O principal objectivo deste estudo foi a avaliação da existência de um gradiente de perturbação tendo em conta a distribuição especial de comunidades macrozoobentónicas intertidais de substrato rochoso, ao longo de um eixo horizontal de três plataformas, e de zonas dentro e ao longo das plataformas, na praia de Buarcos durante a Primavera de 2009. Para tal, parâmetros físico-químicos e taxa de macroalgas foram utilizados na avaliação para confirmar que a amostragem seguiu um gradiente de perturbação, e comparar com os resultados obtidos para a macrofauna. O comportamento de índices ecológicos calculados com os dados dos macroinvertebrados foi comparado com os resultados obtidos com a ferramenta ecológica MarMAT – Marine Macroalgae Assessment Tool. Durante o estudo, um total de 27930 indivíduos de macroinvertebrados foram encontrados correspondendo a 122 taxa diferentes, pertencendo aos Phyla Annelida (44), Arthropoda (41), Cnidaria (1), Echinodermata (2) e Mollusca (31), Nematoda (1), Nemertea (1) e Sipuncula (1). As espécies Mytilus galloprovincialis (densidade média de 14345.4 ind m-2) e Chthamalus montagui (densidade média de 12870.4 ind m-2) foram dominantes nas comunidades, representando 39.94% e 35.83% do total de indivíduos, respectivamente, enquanto os restantes taxa representaram individualmente menos de 6%. As várias ferramentas estatísticas e de ordenação permitiram a verificação de um gradiente de perturbação da St A, a plataforma mais próxima do foco pontual de poluição, para a St C, a plataforma mais distante. O gradiente foi também encontrado da zona a (upper shore) para a zona c (lower shore) dentro das duas plataformas mais imediatas, e entre plataformas. Ademais, a St C e a zona c, as duas áreas de amostragem mais afastadas do foco de poluição, foram as que apresentaram maior similaridade (43.14% e 48.47%, respectivamente) com Mytilus galloprovincialis a contribuir maioritariamente para essas similaridades. Os índices ecológicos capturaram as diferenças nas comunidades entre plataformas e entre zonas, e confirmaram a existência daquele gradiente. Os resultados dos índices estiveram de acordo com os resultados obtidos com a ferramenta MarMAT que, de acordo com os EQRs obtidos, indicou que a St A foi a plataforma com pior condição ecológica, enquanto a St C foi a plataforma com melhor condição ecológica. Este estudo contribuiu para um melhor conhecimento das comunidades macrozoobentónicas intertidais de costa rochosa, procurando esclarecer e fundamentar medidas de gestão a implementar em avaliações futuras.
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Silva, Marina Paula Dolbeth Henriques da. "Macrozoobenthic and fish production of the Mondego estuary : anthropogenic and climate variability impact." Doctoral thesis, 2008. http://hdl.handle.net/10316/9644.
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Stow, Catherine Anne. "Spatial and temporary variations in macrozoobenthic communities in KwaZulu-Natal temporarily open/closed estuaries." Thesis, 2011. http://hdl.handle.net/10413/8523.
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Estuaries are complex ecosystems, typified by remarkable fluctuations in environmental conditions. In addition to this natural variability, stochastic events and anthropogenic influences effect change at different spatial and temporal scales. Macrozoobenthic invertebrates are preferable biological indicators because of their sensitivity to variations in habitat quality. This thesis describes inherent changes in the macrozoobenthos of temporarily open/closed estuaries (TOCEs) in KwaZulu-Natal, ‘change’ as measured in spatial and temporal community differences using various community metrics, namely species composition, abundance and diversity. Standard and widely published quantitative sampling techniques were employed, with simultaneous measurements of ambient physico-chemical conditions, including sediment characteristics. The thesis is in three parts. Regional distributions and long-term decadal-type changes in macrozoobenthic community structure were determined for 31 TOCEs using historical data (1998/9) compared with more recently collected data (2009/10). Results showed that, although of the same estuary type, the macrozoobenthic communities of these estuaries differed significantly. Furthermore, community composition did not reflect a north to south progression of predominantly tropical species to predominantly warm-temperate species. In the last decade, the macrozoobenthos of these systems had indeed changed (in composition, abundance and/or diversity), the scale of change within each estuary being estuary-dependent. The recolonisation of two urban and non-urban estuaries by macrozoobenthos following a stochastic flood disturbance was investigated, describing the short-term community changes during the recovery process. Differential recolonisation patterns were attributed to inherent differences in community composition and not to the influence of urbanisation. Recolonisation was marked by distinct changes in community structure, with the recovery trajectory being interrupted by localised disturbances (e.g. change of mouth state). Species indicative of the observed spatial and temporal community changes were examined for similarities in habitat association and trophic characteristics. The species that were representative of these KwaZulu-Natal TOCEs were identified and included common and highly abundant generalists of varying trophic groups. In conclusion, the present findings illustrated the effectiveness of using macrozoobenthic communities to depict ‘change’ over multiple temporal and spatial scales. This also supports their usefulness as a study group in environmental monitoring and detecting the loss of ecological functioning and biodiversity in estuaries in the long- and short-term.Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.
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Dannheim, Jennifer [Verfasser]. "Macrozoobenthic response to fishery : trophic interactions in highly dynamic coastal ecosystems = Makrozoobenthische Reaktion auf Fischerei / Jennifer Dannheim." 2007. http://d-nb.info/986977942/34.
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URBÁNEK, Marek. "Potrava plůdku candáta obecného (Sander lucioperca) v rybnících s různým způsobem managementu." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-320525.
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The aim of this study was a comphensive assessment of the food of pikeperch fry in the monoculture rearing from the stage of summer fry to the stage of autumn fry in ponds with three different types of management and assessment of the influence of individual treatments for pikeperch production. The experiment was performed in small ponds in experimental facility of FFPW in Vodňany. The variants of pond treatment were: a) ponds with additional prey fish (fry of common carp (C. carpio) and grass carp (C. idella)), b) ponds with installed substrate from heather, c) control variant without any support of natural food of pikeperch. All treatments had four repetitions. Rearing of pikeperch fry lasted 97 days. In all treatments, the opportunistic food strategy of pikeperch fry was recorded during the whole period of rearing and the main recorded food was macrozoobenthos, especially insect larvae. Bigger species of zooplankton had also been often found in the stomachs of pikeperch. Considerable development of macrozoobenthos in all experimental ponds was probably caused by the presence of submerged macrophytes. Thus, this factor made harder to estimate influence of installed substrates from heather for production of pikeperch fry and composition of its food. In the treatment with prey fish, the total length (F (9. 450) = 91.1; p < 10-3) and weight (F (9. 450) = 61.9; p < 10-3) of pikeperch fry were for the whole period of rearing significantly higher in comparison to the other treatments. In addition, the survival of pikeperch in the treatment with prey fish reached to 56 - 92,4 % at the end of rearing. In the treatment with substrate from heather, the total length and weight of pikeperch was significantly higher in comparison to the control treatment only in the first term of sampling. In the rest of pikeperch fry rearing period were the values comparable or higher in control treatment. Thus, for the rearing of pikeperch from the stage of summer fry to the stage of autumn fry is appropriate to stock prey fish in ponds. In comparison to installation of artificial substrate, the diversity of water environment, which is subsequently able to provide sufficiently wide natural food for reared pikeperch, seems to be more decisive.
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GRACÍK, Jan. "Využití umělých substrátů pro hodnocení kvality odtékající vody z organických a konvenčních kaprových rybníků." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-320539.
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The objective of this diploma thesis was to evaluate the quality of the water after flow through the ponds with conventional (Blatensko, Czech Republic) and organic (Waldviertel, Austria) technologies using the colonization of artificial substrates by macrozoobenthos (MZB) to asses the differences in the influence of different managements of pond farming (organic vs. traditional) on water quality. Samplings were performed in monthly intervals (AprilSeptember 2016) at nine inflow and outflow profiles of four ponds. Samples of MZB were processed in the laboratory. Evaluation of MZB was supplemented by in-situ monitoring of basic parameters of the aquatic environment. The resulting values of saprobic index (SI) match the water quality in outlets in the range valid for the beta to alpha mesosabrobity (SI 2.302.62). In the inlets to the Skaličný and Haslauerteich ponds, where the SI value corresponded the betamesosabrobity (SI 2.482.49), the discharged water quality in the outlet was insignificantly (p>0,05) deteriorated to the alphamesosabrobity (SI 2.54 2.62). On the contrary, in the inlet to the Gebhartsteich pond, where the value SI matched the alphamesosabrobity (SI 2.57), water quality in the outlet was insignificantly (p>0,05) slightly improved (SI 2.54), but the degree of saprobity has not changed. Similarly, in the inlet to the Pančár pond, where the SI value matched betamesosabrobity (SI 2.30), the outlet water quality was insignificantly (p>0,05) slightly deteriorated (SI 2.33), however again the degree of saprobity remained unchanged. Water quality changes after the flow through the investigated ponds resulted in the increase of the diversity index (H´) and vice versa (the worse water quality the lower H´). According to the analysis of the data of environmental conditions in organic and conventional carp ponds, they did not differ significantly. Also the species richness and the total number of individuals were not significantly different. The results of this diploma thesis demonstrated that the applied organic technologies of fish culture in monitored ponds did not have any significant impact (improvement) on the quality of aquatic environment and the composition of macrozoobenthos in the recipients of farm outflows, and also that no significant differences (deterioration) can be documented in the outflows from conventional ponds compared to the organic pond farming management.
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Gogina, Mayya [Verfasser]. "Investigation of interrelations between sediment and near-bottom environmental parameters and macrozoobenthic distribution patterns for the Baltic Sea / vorgelegt von Mayya Gogina." 2010. http://d-nb.info/1006893431/34.
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SVAČINA, Petr. "Vliv rybníků a rybničních soustav na složení bentosu horní Lužnice." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-154928.
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The work is focused on monitoring changes in benthic communities in the longitudinal gradient of the river Lužnice. The river flows through to the pond area Třeboňsko and the largest pond of the Czech Republic - Rožmberk. It is examine affect of pond on benthic communities. The work involves collecting benthos according to the PERLA method on four profile in four seasons, the analysis of chemical parameters and data processing. The values of SI (saprobiological index) in the longitudinal gradient were from SI 1.8 to SI 2.6. SI values were at the outflow of Rožmberk higher than at inflow. The lowest values were in the first profile Suchdol (SI 1,8 ? SI 2,1) and higher values were in the last profile Vlkov (SI 2,4 ? 2,6). The chemical parameters at outflow were observed increased values of BOD5, TOC, NL105, NL505, chlorophyll and total P but lower values of nitrogen forms (Ntotal,NH4, N-NO3-). On the each profile was the significant change in the incidence or absence of certain groups. Profiles Suchdol and Hlína were diferent than Lužnice and Vlkov especially in the presence of stoneflies, dragonflies, beetles, and individuals generally indicates good water quality. Profiles at outflows from Rožmberk (Lužnice and Vlkov) showed a continued presence of bloodsuckers and more species indicating high organic pollution. NMDS method confirmed impact of sites in communities rather than period (R2 = 0.6 at significance level of p = 0.001).
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ZIKMUND, Hynek. "Společenstvo fytofilního bentosu v rybnících." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-188590.
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Community of phytophilous macrozoobenthos (PM) represents an important component of fishponds ecosystems concerning biomass as well as essential part of food webs. There are evident linkages between PM and water macrophytes. Their influence on PM is the main topic of many scientific papers which state three main water macrophyte characters with the strongest impact on PM - coverage, biomass and morphological complexity. The main aim of this diploma theses was to analyse linkages between four different water macrophyte species and PM in eight different fishponds devided into two groups according their localisation- třeboňské a rakouské. Water macrophyte species have any influence on PM abundance in both fishpond groups. Water macrophyte species have significant influence on biomass of PM in třeboňské and rakouské fishponds analysed together and also in both fishpond groups analysed separately. PM biomass was significantly higher in Glyceria maxima during first sampling period in both fishpond groups. Water macrophyte species have significant influence on PM diversity in třeboňské and rakouské fishponds analysed together and in rakouské fishponds group analysed separately. Just one variable, water macrophyte species, was analysed in my diploma thesis, but some others abiotic and biotic variables influence phytophilous macrozoobenthos community in fishponds littoral zones as well. That´s why conclusions of this thesis should be interpreted circumspectly.
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Schroeder, Alexander [Verfasser]. "Community dynamics and development of soft bottom macrozoobenthos in the German Bight (North Sea) 1969 - 2000 = Dynamik und Entwicklung makrozoobenthischer Weichbodengemeinschaften in der Deutschen Bucht (Nordsee) 1969 - 2000 / Alexander Schroeder." 2004. http://d-nb.info/975328174/34.
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Hanzlíková, Lenka. "Zatížení sedimentů a makrozoobentosu v urbanizovaném toku Botič stopovými kovy." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-337119.
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Trace element bioaccumulation in benthic organisms is important part of aquatic environment pollution research, since water and sediment analysis itselfs do not provide significant information about bioavailability of contaminants and the results mostly shows just current pollution at the time of sampling. This study focuses on urban streams contamination which are currently significant source of trace elements. Botic stream was chosen as exemplary, because it is affected by many combined sewer system overflows which are sources of contamination in times of heavy rain and flood. Load several sampling took place on 10 stream sites during the year of 2012. This thesis deals with 11 trace elements concretelly Cd, Co, Cr, Cu, Hg, Ni, Zn, As, Fe, Pb and Al. Trace elements were assessed in both benthic organisms and sediment. As well taxons were selected from benthic organisms, which are widely found at any time of the reference year: caddisflies of family Hydropsychidae, leeches Erpobdella sp. and mayflies of Baetidae family. Sediment analysis included sequential extraction which divided trace elements into 4 fractions according to mobility. Based on the results, bioavailability was assessed on observed elements and correlation between concentration in bethos and sediment was tested. Finally, impact of...
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PEŘINOVÁ, Eliška. "Diverzita makrozoobentosu v Evropsky významné lokalitě výskytu raka kamenáče (Austropotamobius torrentium)." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-395961.
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The "Zákolanský potok" takes part in European nature program Special Area of Conservation because of the presence of stone crayfish (Austropotamobius torentium), which is listed as threatened species. The area around brook is intensively agriculturally cultivated. Water from wastewater treatments plants is drained to the local brooks. The aim of the work was to describe diversity of macrozoobenthos on the brook called "Zákolanský potok". Further aim was to evaluate the ecological condition of the watercourse using biotic indexes. The samples of macrobenthos were taken from three profiles in five sampling periods. Profile 1 was control, profile 2 was under the wastewater treatments plants and the third profile was placed down the stream. Diversity, biomass, saprobic index, BMWP, and ASTP scores were evaluated for the community of macrozoobenthos. The saprobic index was evaluated to the beta-mezosaprobity value (2.0-2.4) in the first profile, the saprobic index on the second profile showed a relatively wide range from worse oligosaprobity to worse beta-mesosaprobity (1.2-2.4). On the third profile, the saprobic index ranged from better beta-mesosaprobity to better alpha-mesosaprobity (1.6-2.6). The BMWP and ASPT scores in all profiles refer to medium to low quality aquatic environments. The diversity of the community gained the best values on the 3rd profile, here was found with one more taxon than on the 1st profile. With increasing organic load, diversity decreased on the 2nd profile, although a more sensitive species was found here.