Les milieux côtiers subissent de fortes pressions dues aux activités anthropiques. Ces pressions vont parfois impacter les écosystèmes benthiques. En Europe, des réglementations internationales, telle que la Directive Cadre sur l’Eau (DCE), ont vu le jour. La DCE a fixé un cadre pour obtenir le retour et le maintien d’un bon état écologique pour les masses d’eau côtières, jusqu’à un mile de la côte. Pour vérifier si ce bon état écologique est atteint, des outils de mesure adaptés et performants sont nécessaires. L’utilisation d’indices biotiques basés sur les faunes de foraminifères benthiques est un des moyens pour mesurer l’état des écosystèmes. Ces indices basés sur les faunes de foraminifères sont en pleine expansion, notamment en Méditerranée. En termes de méthodologie, nous avons pu améliorer une technique de concentration des foraminifères benthiques par séparation par densité, qui accélère le traitement des échantillons. L’indice TSI-Med a la particularité d’apporter une correction pour l’état trophique naturel, c’est-à-dire le taux d’enrichissement naturel en matière organique, sur la base de la granulométrie du sédiment. Nos données suggèrent néanmoins que cette correction est encore insuffisante. Nous avons également comparé plusieurs indices biotiques basés sur les faunes de foraminifères benthiques le long des côtes méditerranéennes françaises. Les indices basés sur la diversité, notamment l’exp(H’bc), ne sont pas adaptés à notre zone d’étude oligotrophe. Les indices basés sur les groupes écologiques d’espèces que nous avons testés (TSI-Med, Foram-AMBI et FSI) sont plutôt bien corrélés. Le principal facteur qui va induire des différences entre ces indices est la liste d’assignation écologique des espèces. Trop d’espèces n’ont pas encore été assignées et l’assignation de plusieurs espèces majeures est problématique. Néanmoins, nous avons montré que ces indices sont efficaces à détecter l’impact d’un enrichissement en matière organique diffus et/ou provenant de source ponctuelle, telle que les rejets de stations d’épuration (côte israélienne). Pour perfectionner ces indices, des efforts de caractérisation écologique des espèces doivent être poursuivis. / Coastal environments suffer from anthropogenic activities. Various types of pressure can have large impacts on benthic ecosystems. In Europe, international regulations, such as the Water Framework Directive (WFD), have been implemented. The WFD aims to attain and sustain a good ecological status for all coastal waters, up to one mile from the coast. To verify whether this good status has been reached, adapted and efficient measuring tools are needed. The use of biotic indices based on foraminiferal faunas are a mean to assess the ecosystem status. The use of indices based on foraminiferal faunas rapidly increases, especially in the Mediterranean. In terms of methodology, we were able to improve a method to concentrate benthic foraminifera by density separation, which accelerates the sample treatment. The TSI-Med index includes a correction to take into account the natural trophic state, i.e., the natural enrichment rate in organic matter, on the basis of sediment grain size. However, our data suggest that the applied correction is still insufficient. We also compared several biotic indices based on benthic foraminiferal faunas along the French Mediterranean coast. Indices based on diversity, such as the exp(H’bc), are not suited for our oligotrophic study area. The results of three tested indices based on ecological groups (TSI-Med, Foram-AMBI, FSI) are well correlated. The main factor inducing differences between the indices is the list of ecological assignments for the various species. In general, too many species have not yet been assigned to ecological categories and the assignment of several major species is problematic. Nevertheless, we show that the indices are already efficient in detecting the impact of diffusive organic matter enrichment or enrichment from point sources, such as sewage outlets (Israelian coast). To further perfection the foraminiferal indices, the efforts of ecological assignments of species have to be continued

Após a conferência das nações unidas de 1972, a poluição ambiental começou a se tornar de fato um assunto preocupante. A explosão do crescimento populacional, junto com o desenvolvimento tecnológico, promoveu aumento dos níveis de contaminantes existentes no meio ambiente. Em consequência disso, metodologias são sempre investigadas e testadas, para propor uma forma de monitoramento com resposta relativamente rápidas e seguras, tornando de fato a atividade de monitoramento eficiente, podendo assim, identificar possíveis fontes de contaminação. Organismos vivos atualmente estão compondo essas estratégias de monitoramento, pois garante uma reposta segura e eficaz, e ao mesmo tempo com uma área de cobertura de monitoramento bastante ampla. Nesse grupo encontramse os insetos, mais especificamente as abelhas Apis mellifera (L.), que realizam viagens exploratórias em busca de recurso alimentar e acabam por estarem em contato com diversos setores do ambiente. Com isso o objetivo do presente trabalho foi avaliar o potencial do mel de abelhas A. mellifera como bioindicador de poluição por metais pesados no ambiente, identificando sua origem botânica, bem como, seus aspectos físico-químicos como a presença de elementos traço (Zn, Cu, Pb e Cd), utilizando-se da técnica de voltametria de redissolução anódica de pulso diferencial. O trabalho foi desenvolvido na Escola Superior de Agricultura \"Luiz de Queiroz\" - ESALQ/USP, no Laboratório de Insetos Úteis, com uma contribuição do Laboratório de Tecidos Vegetais. Foram encontrados 34 tipos polínicos nas amostras de mel ao longo do período de coleta, pertencentes a 20 famílias botânicas, sendo Arecaceae, Fabaceae/Mimosoideae e Myrtaceae as famílias mais representadas. Todas as amostras apresentaram HMF e teores de cinzas dentro do padrão estabelecido pela legislação, apresentando flutuações durante o período de estudo. Em relação aos metais detectados, o chumbo (Pb) foi o elemento que apresentou, em média, a maior concentração no mel de A. mellifera, cerca de 2,11 mg.kg-1. Seguido do Zinco, com média de 1,56 mg.kg-1, e logo após o Cobre com valores médios de 0,35 mg.kg-1. Cádmio não esteve presente em nenhuma amostra analisada. Conclui-se que o mel pode ser utilizado como ferramenta de bioindicação associado a outros produtos apícolas. / After the United Nations Conference in 1972, the environmental pollution became a really concern issue. The population growth explosion, along the technological development, has promoted increasing environmental level contaminants. Hence, methodologies are always investigated and tested to propose a monitoring way with relatively fast and safe response, making the monitoring activity efficient indeed. Thus, it can identify possible contamination sources. Organisms are lately compounding these monitoring strategies since they ensure an effective and safe response, at the same time embracing a quite wide monitoring coverage area. The insects are included in this group of organisms, specifically the bees Apis mellifera (L.), that display exploratory flights in search of food resources, reaching a variety of environmental section therefore. Therewith, the aims of this investigation were to evaluate the Apis mellifera honey potential as heavy metal pollution bio-indicator in the environment; to identify its botanical origin, as well as its physico-chemical aspects, whereby the presence of trace elements (Zn, Cu, Pb and Cd) using the technique of anodic stripping voltammetry differential pulse. The investigations were conducted at Escola Superior de Agricultura \"Luiz de Queiroz\" - ESALQ/USP, in the Economically Important Insects laboratory, with a contribution of Tissue Plants laboratory. It was found 34 pollen types in the honey samples throughout the collection season. The pollen belong to 20 botanical families, and Arecaceae, Fabaceae/Mimosoideae and Myrtaceae being the most represented ones. All the samples showed HMF levels and ashes within the standard established by law, with fluctuations during the study period. Regarding to detected metals, lead (Pb) was the element which showed the highest average concentration in Apis mellifera honey, about 2,11 mg.kg-1 throughout the study season. Zinc followed, with average of 1.56 mg.kg-1, and right after the copper with average values of 0.35 mg.kg-1. Cadmium was not present in any analyzed sample. It concludes that honey can be used as a bio-indication tool associated with other bee products.

Após a conferência das nações unidas de 1972, a poluição ambiental começou a se tornar de fato um assunto preocupante. A explosão do crescimento populacional, junto com o desenvolvimento tecnológico, promoveu aumento dos níveis de contaminantes existentes no meio ambiente. Em consequência disso, metodologias são sempre investigadas e testadas, para propor uma forma de monitoramento com resposta relativamente rápidas e seguras, tornando de fato a atividade de monitoramento eficiente, podendo assim, identificar possíveis fontes de contaminação. Organismos vivos atualmente estão compondo essas estratégias de monitoramento, pois garante uma reposta segura e eficaz, e ao mesmo tempo com uma área de cobertura de monitoramento bastante ampla. Nesse grupo encontramse os insetos, mais especificamente as abelhas Apis mellifera (L.), que realizam viagens exploratórias em busca de recurso alimentar e acabam por estarem em contato com diversos setores do ambiente. Com isso o objetivo do presente trabalho foi avaliar o potencial do mel de abelhas A. mellifera como bioindicador de poluição por metais pesados no ambiente, identificando sua origem botânica, bem como, seus aspectos físico-químicos como a presença de elementos traço (Zn, Cu, Pb e Cd), utilizando-se da técnica de voltametria de redissolução anódica de pulso diferencial. O trabalho foi desenvolvido na Escola Superior de Agricultura \"Luiz de Queiroz\" - ESALQ/USP, no Laboratório de Insetos Úteis, com uma contribuição do Laboratório de Tecidos Vegetais. Foram encontrados 34 tipos polínicos nas amostras de mel ao longo do período de coleta, pertencentes a 20 famílias botânicas, sendo Arecaceae, Fabaceae/Mimosoideae e Myrtaceae as famílias mais representadas. Todas as amostras apresentaram HMF e teores de cinzas dentro do padrão estabelecido pela legislação, apresentando flutuações durante o período de estudo. Em relação aos metais detectados, o chumbo (Pb) foi o elemento que apresentou, em média, a maior concentração no mel de A. mellifera, cerca de 2,11 mg.kg-1. Seguido do Zinco, com média de 1,56 mg.kg-1, e logo após o Cobre com valores médios de 0,35 mg.kg-1. Cádmio não esteve presente em nenhuma amostra analisada. Conclui-se que o mel pode ser utilizado como ferramenta de bioindicação associado a outros produtos apícolas. / After the United Nations Conference in 1972, the environmental pollution became a really concern issue. The population growth explosion, along the technological development, has promoted increasing environmental level contaminants. Hence, methodologies are always investigated and tested to propose a monitoring way with relatively fast and safe response, making the monitoring activity efficient indeed. Thus, it can identify possible contamination sources. Organisms are lately compounding these monitoring strategies since they ensure an effective and safe response, at the same time embracing a quite wide monitoring coverage area. The insects are included in this group of organisms, specifically the bees Apis mellifera (L.), that display exploratory flights in search of food resources, reaching a variety of environmental section therefore. Therewith, the aims of this investigation were to evaluate the Apis mellifera honey potential as heavy metal pollution bio-indicator in the environment; to identify its botanical origin, as well as its physico-chemical aspects, whereby the presence of trace elements (Zn, Cu, Pb and Cd) using the technique of anodic stripping voltammetry differential pulse. The investigations were conducted at Escola Superior de Agricultura \"Luiz de Queiroz\" - ESALQ/USP, in the Economically Important Insects laboratory, with a contribution of Tissue Plants laboratory. It was found 34 pollen types in the honey samples throughout the collection season. The pollen belong to 20 botanical families, and Arecaceae, Fabaceae/Mimosoideae and Myrtaceae being the most represented ones. All the samples showed HMF levels and ashes within the standard established by law, with fluctuations during the study period. Regarding to detected metals, lead (Pb) was the element which showed the highest average concentration in Apis mellifera honey, about 2,11 mg.kg-1 throughout the study season. Zinc followed, with average of 1.56 mg.kg-1, and right after the copper with average values of 0.35 mg.kg-1. Cadmium was not present in any analyzed sample. It concludes that honey can be used as a bio-indication tool associated with other bee products.

L’objectif de ce travail de thèse est d’évaluer le potentiel de nouveaux bio-essais in vitro et in vivo basés sur le poisson zèbre pour la biosurveillance de la contamination chimique de l’eau par les xeno-estrogènes. Pour cela, les bio-essais ont été appliqués pour évaluer les effets de polluants aquatiques environnementaux seuls, mais aussi en mélanges simples (reconstitués) et complexes (échantillons environnementaux). L’évaluation d’échantillons d’eau à travers les bioessais in vitro humain (MELN) et poisson zèbre (ZELH-zfERβ2) a montré des différences qualitatives et quantitatives de réponse, non expliquées par les molécules estrogéniques détectées. Afin de mieux comprendre ces différences, l’activité de polluants aquatiques a été caractérisée sur les différents modèles, individuellement et au sein de mélanges de 2 à 12 polluants, combinant molécules estrogéniques et non estrogéniques pour simuler des situations environnementales.Les résultats obtenus montrent que les bio-essais basés sur le poisson zèbre répondent différemment, et parfois de manière opposée, au modèle humain MELN aux mélanges reconstitués. Ces différences s’expliquent par des sensibilités différentes à certaines molécules entrainant des interactions avec la réponse aux xeno-oestrogènes spécifiques à chaque modèle biologique. Dans son ensemble, ce travail montre que les particularités biologiques de chaque bioessai peuvent influencer la réponse des xeno-estrogènes quand présents au sein de mélange avec d’autres polluants. Ces résultats sont discutés au regard de l’utilisation de bio-essais dans l’évaluation de la contamination chimique des masses d’eau. / This PhD thesis aims at assessing the potential of innovative in vitro and in vivo zebrafish based bioassays for biomonitoring of surface water contamination by xeno-estrogens. For this purpose, the bioassays were applied to assess the effect of environmentally relevant surface water pollutants, alone and in simple (artificial) and complex (environmental samples) mixtures. The screening of surface water samples in zebrafish- (ZELH-zfERβ2 cells) and human-based (MELNcells) bioassays revealed qualitative and quantitative differences which could not be entirely explained by the xeno-estrogens identified. To better understand the response of bioassays to complex environmental mixtures, the activity of environmentally relevant surface waterpollutants was characterized across the bioassays, alone and in 2 to 12-component mixtures combining estrogenic and non-estrogenic chemicals to simulate an environmental contamination.The results indicate that zebrafish-based bioassays have a different and even in some cases an opposite response to the simple mixtures compared with the human-based bioassay MELN. These differences are explained by different sensitivity to some pollutants leading to bioassay-specific interactions with estrogen receptor activation. Al together, this work shows that the biological particularities of each bioassay can influence the response to estrogenic chemicals when mixed with other environmental pollutants, opening the discussion regarding their implementation in chemical water biomonitoring.

The European Water Framework Directive 2000 established a new emphasis for the management of freshwaters by setting ecologically-based water quality targets that are to be achieved through holistic, catchment-scale, ecosystem management. However, significant knowledge gaps exist in the understanding of the cumulative effectiveness of multiple mitigation measures on a number of pollutants at a catchment scale. This research contributes to improved understanding of the effectiveness of an ecosystem management approach to deliver catchment-scale water quality improvements on the National Trust Holnicote Estate on Exmoor, UK. This research is part of a larger multi-objective project funded by the UK Department for Environment, Food and Rural Affairs (Defra), to demonstrate the benefits of land use interventions for the management of flood risk. This thesis evaluates the effects of upland ditch blocking on physico-chemical and biological parameters of water quality in an upland Horner Water catchment one year after habitat restoration, and establishes a solid baseline for the monitoring of the effects of current and future land management changes in a lowland, intensively managed, agricultural Aller catchment. The spatial variability of soil physical and chemical properties (bulk density, total carbon (TN), nitrogen (TN), C:N ratio, δ15N, total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP)) and water quality determinands (suspended sediment (SS), dissolved organic carbon (DOC), total particulate carbon (TPC), total oxidised nitrogen (TON) and dissolved reactive phosphorus (DRP)) in the two study catchments with contrasting land use has been characterised and linked to the prevailing land use. Agricultural land use resulted in extensive homogenisation of soil properties. The spatial dependence of all soil properties, except for bulk density and δ15N, was stronger in the agricultural than the semi-natural catchment (nugget:sill ratio 0.10-0.42 in the Aller and 0.15-0.94 in Horner Water), while bulk density, TP, inorganic phosphorus (IP), organic phosphorus (OP), C:N ratio, δ15N and carbon storage showed a longer range of spatial auto-correlation in the agricultural catchment (2,807-3,191 m in the Aller and 545-2,599 m Horner Water). The central tendency (mean, median) of all soil properties, except for IP and δ15N, also differed significantly between the two catchments (P < 0.01). The observed extensive alteration of soil physical and chemical properties in the agricultural catchment is likely to have long-term implications for the restoration of ecosystem functioning and water quality management. The intensive land use seems to have resulted in an altered ‘catchment metabolism’, manifested in a proportionally greater total fluvial carbon (dissolved and particulate) export from the agricultural than the semi-natural catchment. The agricultural catchment supported significantly higher DOC concentrations (P < 0.05) and the quality of DOC differed markedly between the two study catchments. The prevalence of more humic, higher molecular weight compounds in the agricultural catchment and simpler, lower molecular weight compounds in the semi-natural catchment, indicated enhanced microbial turnover of fluvial DOC in the agricultural catchment as well as additional allochtonous terrestrial sources. During an eight month period for which a comparable continuous turbidity record was available, the estimated SS yields from the agricultural catchment (25.5-116.2 t km2) were higher than from the semi-natural catchment (21.7-57.8 t km2). Further, the agricultural catchment exported proportionally more TPC (0.51-2.59 kg mm-1) than the semi-natural catchment (0.36-0.97 kg mm-1) and a similar amount of DOC (0.26-0.52 kg mm-1 in the Aller and 0.24-0.32 kg mm-1 in Horner Water), when normalised by catchment area and total discharge, despite the lower total soil carbon pool, thus indicating an enhanced fluvial loss of sediment and carbon from the intensively managed catchment. Whilst detection of catchment-scale effects of mitigation measures typically requires high resolution, resource-intensive, long term data sets, this research has found that simple approaches can be effective in bridging the gap between fine scale ecosystem functioning and catchment-scale processes. Here, the new macro-invertebrate index PSI (Proportion of Sediment-sensitive Invertebrates) has been shown to be more closely related to a physical measure of sedimentation (% fine bed sediment cover) (P = 0.002) than existing non-pressure specific macro-invertebrate metrics such as the Lotic Index for Flow Evaluation (LIFE) and % Ephemeroptera, Plecoptera & Trichoptera abundance (% EPT) (P = 0.014). Further testing of PSI along a pronounced environmental gradient is recommended as PSI and % fine bed sediment cover have the potential to become a sensitive tool for the setting and monitoring of twin sedimentation targets. Upland ditch management has not had any discernible effect on water quality in the semi-natural upland catchment one year after restoration, which may be due to the short-term post-restoration monitoring period but may also reflect benign effects of large-scale earth moving works on this high quality environment. The conceptual understanding of catchment processes developed in this thesis suggests that cumulatively, the recently completed mitigation works in the lowland agricultural catchment will likely result in reduced sediment and nutrient input into the aquatic environment. However, further research is needed to build on this detailed baseline characterisation and inform the understanding of the effectiveness of combined mitigation measures to reduce the flux of multiple contaminants at the catchment scale.

Human related activities have influenced the rivers of the southern Western Cape since as early as the 1700’s. As there is no detailed information available on ecological status of the Holsloot River, a tributary of the Breede River, this study aimed to gain insight into the effect of impacts associated with human activities on the habitat integrity of this river. The study intended to understand how seasonal changes, catchment characteristics and events are reflected in the ecological status of habitats along the river by applying bio-monitoring and river health measurements at selected sites in the upper, middle and lower reaches of the Holsloot River and compare the results to that of an undisturbed reference site. Results obtained in this study are compared with data gathered in 2008/2009 to determine if the ecological status of the river had changed in the period between the two sampling times. The study included assessment of the ecological status of the river based on standard bio-monitoring protocol (SASS5, IHI, IHAS and VEGRAI) as well as in situ water quality analysis (pH, dissolved oxygen, electrical conductivity and total dissolved solids). The construction of the instream Stettynskloof Dam changed the configuration of the riparian zone and river channel in the upper catchment area. Agricultural- and other human related activities, with consequent water abstraction, non-point-source pollution, loss of riparian vegetation, as well as dense stands of alien invader plants influence flow patterns and affects river ecology, especially in the dry summer months. Providing sufficient stream flow and adequate water levels, human related activities can create a larger variety of habitat types available that can support larger biodiversity and higher productivity. The level of inundation and stream flow, influenced by water abstraction as well as irrigation return-flow from extensive drainage systems especially in the dry months, contribute to the loss of biodiversity in the middle and lower reaches of the river. Where the upper reaches of the river are largely natural with few modifications, the habitat integrity deteriorates in the middle reaches so much so that ecosystem functioning are collectively impaired in lower reaches due to human related impacts. Sensitive macro-invertebrates found at lower seriously impacted parts of the river however, were in all probability washed down from lower impacted upstream habitats and may expectedly be able to again occupy habitats downstream if water quality and habitat availability improves. / Environmental Sciences / M. Sc. (Environmental Science)

Human related activities have influenced the rivers of the southern Western Cape since as early as the 1700’s. As there is no detailed information available on ecological status of the Holsloot River, a tributary of the Breede River, this study aimed to gain insight into the effect of impacts associated with human activities on the habitat integrity of this river. The study intended to understand how seasonal changes, catchment characteristics and events are reflected in the ecological status of habitats along the river by applying bio-monitoring and river health measurements at selected sites in the upper, middle and lower reaches of the Holsloot River and compare the results to that of an undisturbed reference site. Results obtained in this study are compared with data gathered in 2008/2009 to determine if the ecological status of the river had changed in the period between the two sampling times. The study included assessment of the ecological status of the river based on standard bio-monitoring protocol (SASS5, IHI, IHAS and VEGRAI) as well as in situ water quality analysis (pH, dissolved oxygen, electrical conductivity and total dissolved solids). The construction of the instream Stettynskloof Dam changed the configuration of the riparian zone and river channel in the upper catchment area. Agricultural- and other human related activities, with consequent water abstraction, non-point-source pollution, loss of riparian vegetation, as well as dense stands of alien invader plants influence flow patterns and affects river ecology, especially in the dry summer months. Providing sufficient stream flow and adequate water levels, human related activities can create a larger variety of habitat types available that can support larger biodiversity and higher productivity. The level of inundation and stream flow, influenced by water abstraction as well as irrigation return-flow from extensive drainage systems especially in the dry months, contribute to the loss of biodiversity in the middle and lower reaches of the river. Where the upper reaches of the river are largely natural with few modifications, the habitat integrity deteriorates in the middle reaches so much so that ecosystem functioning are collectively impaired in lower reaches due to human related impacts. Sensitive macro-invertebrates found at lower seriously impacted parts of the river however, were in all probability washed down from lower impacted upstream habitats and may expectedly be able to again occupy habitats downstream if water quality and habitat availability improves. / Environmental Sciences / M. Sc. (Environmental Science)