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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 macrozoobenthos. / Abstract

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]

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.

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.

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.

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).

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...

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.

<p align="justify"><i>Typologie des cours d’eau en Wallonie et caractérisation par la faune invertébrée</i><br>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.</p> <p align="justify"><i>Conditions de référence types et définition de l’état écologique des rivières en Wallonie à l’aide de métriques biocénotiques basées sur les invertébrés</i><br> 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.</p> <p align="justify"><i>Exercice pilote d’inter-étalonnage</i><br> 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.</p> <p align="justify"><i>Espèces exotiques et invasives</i><br>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 (<i>Hypania invalida</i>) et trois crustacés (<i>Hemimysis anomala, Dikerogammarus villosus, D. haemobaphes</i>). Peu avant, en 1995, le bivalve asiatique <i>Corbicula fluminea</i> et l’amphipode nord-américain <i>Crangonyx pseudogracilis</i> ont également été enregistrés pour la première fois. La dynamique des invasions a été étudiée et discutée.</p> <p align="justify">L’<i>état biologique actuel</i> (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 ».</p> <b>Abstract</b> <p align="justify"><i>River typology in Wallonia and invertebrate fauna characterization</i><br>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.</p> <p align="justify"><i>Type-specific reference conditions and ecological status definition of rivers in Wallonia using invertebrate biocenotic metrics</i><br> 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.</p> <p align="justify"><i>Intercalibration pilot exercise</i><br> 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.</p> <p align="justify"><i>Exotic and invasive species</i><br> 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 (<i>Hypania invalida</i>) and three Crustacea (<i>Hemimysis anomala, Dikerogammarus villosus, D. haemobaphes</i>). Earlier, in 1995, the Asian Bivalvia <i>Corbicula fluminea</i> and the North American Amphipod <i>Crangonyx pseudogracilis</i> were also recorded for the first time. The invasions’ dynamics were studied and discussed.</p> <p align="justify"><i>Present biological status</i> (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.</p>