A acidificação oceânica, resultante do aumento da concentração de CO2 atmosférico, vem alterando a química dos oceanos resultando na diminuição de seu pH. Diversos estudos avaliaram as consequências dessa diminuição no pH oceânico nas taxas de calcificação, reprodução e desenvolvimento em diversos modelos marinhos, entretanto estudos relacionados a outros processos fisiológicos, como a imunidade, e estudos com indivíduos adultos são escassos. Ouriços-do-mar são espécies aderidas ao substrato, importantes para a ciclagem de nutrientes no ambiente marinho, sendo também animais utilizados como bioindicadores para monitoramento ambiental; assim o estudo da resposta imune inata desses animais frente à acidificação dos oceanos é de extrema importância para prever possíveis alterações fisiológicas desses animais e sua capacidade de adaptação. O presente trabalho teve como objetivo avaliar as alterações provocadas pela acidificação oceânica na resposta imune e no balanço ácido base de duas espécies de ouriço-do-mar tropicais: Lytechinus variegatus e Echinometra lucunter durante as estações de verão e inverno; para isso foram analisados os índices fagocíticos, a capacidade de adesão e espraiamento celular dos amebócitos fagociticos além do balanço acido base do liquido celomático após o período de 24 horas e cinco dias de exposição aos pHs 7,6 e 7,3. Foi também avaliada a capacidade de recuperação dessas espécies com o objetivo de verificar se os parâmetros alterados pela exposição conseguiam ser reestabelecidos. Os resultados mostraram que a redução no pH da água do mar alterou a proporção celular, reduziu a capacidade de fagocitose e espraiamento dos amebócitos fagocíticos assim como também afetou o balanço ácido-base do líquido celomático. Foram encontradas diferenças também entre as estações do ano sendo estas encontradas apenas na espécie Lytechinus variegatus. O teste de recuperação mostrou que os parâmetros alterados pela exposição tendem a retornar aos valores controles, mostrando que em curto prazo essas alterações podem não ser irreversíveis, entretanto, mais estudos são necessários principalmente avaliando períodos de exposição prolongados. Juntos nossos resultados mostram que a acidificação oceânica prejudica parâmetros imunes extremamente importantes para a eliminação de patógenos e consequentemente a sobrevivência desses animais em um futuro oceano acidificado. / Ocean acidification due to increased atmospheric CO2 concentration is altering ocean chemistry resulting in the decrease of its pH. Several studies evaluated the effects of this decrease in ocean pH on calcification rates, reproduction and development in different marine models, however studies related to other physiological processes such as immunity and studies with adult animals are scarce. Sea urchins are species adhered to the substrate, important for nutrient cycling in the marine environment, also being used as bioindicators for environmental monitoring. Thus the study of the innate immune response of these animals due to the acidification of the oceans is extremely important to predict possible physiological changes of these animals and their ability to adapt to this condition. This study aimed to evaluate the changes caused by ocean acidification in the immune response and in the acid-base balance of two sea urchin tropical species: Lytechinus variegatus and Echinometra lucunter during seasons of summer and winter; for this, indexes of phagocytosis, cell adhesion and spreading ability were analyzed in addition to the acid-base balance of the coelomic fluid after 24 hours and five days of exposure to pH 7.6 and 7.3The recover ability of these species were also evaluated in order to verify if the parameters altered by exposition could be reestablished. The results shows that a reduction in the seawater pH changed the cell proportion, reduced the ability of phagocytosis and phagocytic amoebocyte spreading as well as affected the acid-base balance of the coelomic fluid. Differences were also found between seasons, but only in the specie Lytechinus variegatus. The recovery test showed that the parameters altered by exposure tend to return to control values, showing that in the short term these changes may not be irreversible, however, further studies are necessary mainly those related to prolonged periods of exposure. Together our results show that ocean acidification impairs immune parameters extremely important for the elimination of pathogens and consequently the survival of these animals in a future acidified ocean.

A região de Caraguatatuba encontra-se exposta a duas fontes mais significativas de poluição marinha: efluentes domésticos e derramamentos de petróleo, principalmente pela proximidade com Canal de São Sebastião. O presente estudo objetivou avaliar a qualidade do sedimento da região por meio de ensaios ecotoxicológicos com sedimentos coletados em 21 pontos, no inverno e no verão. Foram realizados ensaios de toxicidade aguda com sedimento total usando os anfípodos Tiburonela viscana e Leptocheirus plumulosus, de toxicidade crônica avaliada pela eclosão de ovos do copépodo Nitokra sp, e de interface sedimento/água com embriões do equinodermata Lytechinus variegatus. O maior número de amostras com toxicidade foi observado na campanha de verão, e o organismo que se mostrou mais sensível foi L. variegatus. Os resultados demostraram maior toxicidade nos sedimentos próximos à planície de maré e saída do Canal de São Sebastião, ao sul, e próximo à Praia de Tabatinga, extremo norte do município. Esta distribuição de pontos com toxicidade segue o padrão de deposição de partículas provenientes do Canal de São Sebastião e se aproxima dos resultados de qualidade sanitária da região. / The Caraguatatuba region is exposed to two significant sources of marine pollution: domestic sewage and oil spills, mainly due to the proximity of the São Sebastião Channel. This study aimed to evaluate the sediment quality of the region through ecotoxicological tests with sediment and sediment / water interface, collected in 21 points, in winter and summer. Acute toxicity tests were conducted with total sediment using the amphipods Tiburonela viscana and Leptocheirus plumulosus, chronic toxicity was evaluate in hatching eggs with the copepod Nitokra sp, and sediment / water interface with Echinodermata Lytechinus variegatus embryos. The largest number of toxic points was obtained in the summer campaign, and the more sensitive organism was L. variegatus. Results showed greater toxicity close to tidal plain and in the São Sebastião Channel mouth, at soul, and next Tabatinga Beach, at northern edge of the municipality. This distribution of toxic points follows the pattern of particle deposition from the São Sebastião Channel, and approaches the results of sanitary quality in the region.

A região de Caraguatatuba encontra-se exposta a duas fontes mais significativas de poluição marinha: efluentes domésticos e derramamentos de petróleo, principalmente pela proximidade com Canal de São Sebastião. O presente estudo objetivou avaliar a qualidade do sedimento da região por meio de ensaios ecotoxicológicos com sedimentos coletados em 21 pontos, no inverno e no verão. Foram realizados ensaios de toxicidade aguda com sedimento total usando os anfípodos Tiburonela viscana e Leptocheirus plumulosus, de toxicidade crônica avaliada pela eclosão de ovos do copépodo Nitokra sp, e de interface sedimento/água com embriões do equinodermata Lytechinus variegatus. O maior número de amostras com toxicidade foi observado na campanha de verão, e o organismo que se mostrou mais sensível foi L. variegatus. Os resultados demostraram maior toxicidade nos sedimentos próximos à planície de maré e saída do Canal de São Sebastião, ao sul, e próximo à Praia de Tabatinga, extremo norte do município. Esta distribuição de pontos com toxicidade segue o padrão de deposição de partículas provenientes do Canal de São Sebastião e se aproxima dos resultados de qualidade sanitária da região. / The Caraguatatuba region is exposed to two significant sources of marine pollution: domestic sewage and oil spills, mainly due to the proximity of the São Sebastião Channel. This study aimed to evaluate the sediment quality of the region through ecotoxicological tests with sediment and sediment / water interface, collected in 21 points, in winter and summer. Acute toxicity tests were conducted with total sediment using the amphipods Tiburonela viscana and Leptocheirus plumulosus, chronic toxicity was evaluate in hatching eggs with the copepod Nitokra sp, and sediment / water interface with Echinodermata Lytechinus variegatus embryos. The largest number of toxic points was obtained in the summer campaign, and the more sensitive organism was L. variegatus. Results showed greater toxicity close to tidal plain and in the São Sebastião Channel mouth, at soul, and next Tabatinga Beach, at northern edge of the municipality. This distribution of toxic points follows the pattern of particle deposition from the São Sebastião Channel, and approaches the results of sanitary quality in the region.

A acidificação oceânica, resultante do aumento da concentração de CO2 atmosférico, vem alterando a química dos oceanos resultando na diminuição de seu pH. Diversos estudos avaliaram as consequências dessa diminuição no pH oceânico nas taxas de calcificação, reprodução e desenvolvimento em diversos modelos marinhos, entretanto estudos relacionados a outros processos fisiológicos, como a imunidade, e estudos com indivíduos adultos são escassos. Ouriços-do-mar são espécies aderidas ao substrato, importantes para a ciclagem de nutrientes no ambiente marinho, sendo também animais utilizados como bioindicadores para monitoramento ambiental; assim o estudo da resposta imune inata desses animais frente à acidificação dos oceanos é de extrema importância para prever possíveis alterações fisiológicas desses animais e sua capacidade de adaptação. O presente trabalho teve como objetivo avaliar as alterações provocadas pela acidificação oceânica na resposta imune e no balanço ácido base de duas espécies de ouriço-do-mar tropicais: Lytechinus variegatus e Echinometra lucunter durante as estações de verão e inverno; para isso foram analisados os índices fagocíticos, a capacidade de adesão e espraiamento celular dos amebócitos fagociticos além do balanço acido base do liquido celomático após o período de 24 horas e cinco dias de exposição aos pHs 7,6 e 7,3. Foi também avaliada a capacidade de recuperação dessas espécies com o objetivo de verificar se os parâmetros alterados pela exposição conseguiam ser reestabelecidos. Os resultados mostraram que a redução no pH da água do mar alterou a proporção celular, reduziu a capacidade de fagocitose e espraiamento dos amebócitos fagocíticos assim como também afetou o balanço ácido-base do líquido celomático. Foram encontradas diferenças também entre as estações do ano sendo estas encontradas apenas na espécie Lytechinus variegatus. O teste de recuperação mostrou que os parâmetros alterados pela exposição tendem a retornar aos valores controles, mostrando que em curto prazo essas alterações podem não ser irreversíveis, entretanto, mais estudos são necessários principalmente avaliando períodos de exposição prolongados. Juntos nossos resultados mostram que a acidificação oceânica prejudica parâmetros imunes extremamente importantes para a eliminação de patógenos e consequentemente a sobrevivência desses animais em um futuro oceano acidificado. / Ocean acidification due to increased atmospheric CO2 concentration is altering ocean chemistry resulting in the decrease of its pH. Several studies evaluated the effects of this decrease in ocean pH on calcification rates, reproduction and development in different marine models, however studies related to other physiological processes such as immunity and studies with adult animals are scarce. Sea urchins are species adhered to the substrate, important for nutrient cycling in the marine environment, also being used as bioindicators for environmental monitoring. Thus the study of the innate immune response of these animals due to the acidification of the oceans is extremely important to predict possible physiological changes of these animals and their ability to adapt to this condition. This study aimed to evaluate the changes caused by ocean acidification in the immune response and in the acid-base balance of two sea urchin tropical species: Lytechinus variegatus and Echinometra lucunter during seasons of summer and winter; for this, indexes of phagocytosis, cell adhesion and spreading ability were analyzed in addition to the acid-base balance of the coelomic fluid after 24 hours and five days of exposure to pH 7.6 and 7.3The recover ability of these species were also evaluated in order to verify if the parameters altered by exposition could be reestablished. The results shows that a reduction in the seawater pH changed the cell proportion, reduced the ability of phagocytosis and phagocytic amoebocyte spreading as well as affected the acid-base balance of the coelomic fluid. Differences were also found between seasons, but only in the specie Lytechinus variegatus. The recovery test showed that the parameters altered by exposure tend to return to control values, showing that in the short term these changes may not be irreversible, however, further studies are necessary mainly those related to prolonged periods of exposure. Together our results show that ocean acidification impairs immune parameters extremely important for the elimination of pathogens and consequently the survival of these animals in a future acidified ocean.

A amônia não ionizada pode ser interferente nos testes de toxicidade com a água intersticial de sedimentos marinhos e estuarinos. Com o objetivo de se encontrar em uma alternativa que minimizasse o efeito da amônia avaliou-se, em paralelo à água intersticial, o método que utiliza a interface sedimento/água. Foram analisadas 25 amostras de sedimento através do teste de toxicidade crônica de curta duração com Lytechinus variegatus. Foi observada correlação significativa entre os efeitos tóxicos para os diversos estágios embrio-larvais e a concentração de amônia não ionizada para os dois métodos avaliados. Quando comparadas com a interface sedimento/água, foram observadas concentrações superiores de amônia não ionizada em todas as amostras de água intersticial, que isoladamente, poderiam causar os efeitos tóxicos observados. Conclui-se que o teste de toxicidade na interface sedimento/água é o método mais adequado para avaliação de sedimentos marinhos e estuarinos, pois possibilitou a utilização de um maior número de resultados de testes de toxicidade do que aquele com água intersticial, uma vez que minimizou a influência da amônia. Foi evidenciada correlação significativa entre os resultados das concentrações de HPAs determinadas nas amostras de sedimento bruto e a toxidade observada nos diversos estágios embrio-larvais, pelo método da água intersticial. Para os metais, obteve-se correlação significativa com os efeitos tóxicos nos referidos estágios determinados na interface sedimento/água. Não foi evidenciada correlação entre a granulometria e o efeito tóxico nas amostras. O registro dos efeitos nos diferentes estágios embrio-larvais mostrou-se bastante útil, pois além de oferecer informações a respeito da toxicidade da amostra (ausência ou presença) possibilitou a hierarquização, em termos da intensidade de efeito adverso, daquelas amostras tóxicas. / Un-ionized ammonia is considered a confounding factor in interstitial water toxicity tests with marine and estuarine sediment. In order to find an alternative in which the ammonia influence is minimized an evaluation of the sediment/water interface method was performed. Sediment samples from 25 sites were analized with the chronic toxicity test with the sea urchin Lytechinus variegatus. There was a significant correlation between both toxicity test results and un-ionized ammonia. Un-ionized ammonia concentrations, which could be responsible for the toxic effects, were higher in all interstitial samples when compared with sediment/water interface. It was conducled that the use of the sediment/water interface toxicity test can minimize the ammonia influence and more toxicity test results could be used. A significative correlation between PAHs in the whole sediment and the toxicity observed on interstitial water was shown. For metals the correlation occurred with sediment/water interface. There was no correlation between grain size and both toxicity test. It was possible to know about the toxicity (presence or absence) and classify the toxic samples in terms of toxic effects with the different stages of L. variegatus.

A amônia não ionizada pode ser interferente nos testes de toxicidade com a água intersticial de sedimentos marinhos e estuarinos. Com o objetivo de se encontrar em uma alternativa que minimizasse o efeito da amônia avaliou-se, em paralelo à água intersticial, o método que utiliza a interface sedimento/água. Foram analisadas 25 amostras de sedimento através do teste de toxicidade crônica de curta duração com Lytechinus variegatus. Foi observada correlação significativa entre os efeitos tóxicos para os diversos estágios embrio-larvais e a concentração de amônia não ionizada para os dois métodos avaliados. Quando comparadas com a interface sedimento/água, foram observadas concentrações superiores de amônia não ionizada em todas as amostras de água intersticial, que isoladamente, poderiam causar os efeitos tóxicos observados. Conclui-se que o teste de toxicidade na interface sedimento/água é o método mais adequado para avaliação de sedimentos marinhos e estuarinos, pois possibilitou a utilização de um maior número de resultados de testes de toxicidade do que aquele com água intersticial, uma vez que minimizou a influência da amônia. Foi evidenciada correlação significativa entre os resultados das concentrações de HPAs determinadas nas amostras de sedimento bruto e a toxidade observada nos diversos estágios embrio-larvais, pelo método da água intersticial. Para os metais, obteve-se correlação significativa com os efeitos tóxicos nos referidos estágios determinados na interface sedimento/água. Não foi evidenciada correlação entre a granulometria e o efeito tóxico nas amostras. O registro dos efeitos nos diferentes estágios embrio-larvais mostrou-se bastante útil, pois além de oferecer informações a respeito da toxicidade da amostra (ausência ou presença) possibilitou a hierarquização, em termos da intensidade de efeito adverso, daquelas amostras tóxicas. / Un-ionized ammonia is considered a confounding factor in interstitial water toxicity tests with marine and estuarine sediment. In order to find an alternative in which the ammonia influence is minimized an evaluation of the sediment/water interface method was performed. Sediment samples from 25 sites were analized with the chronic toxicity test with the sea urchin Lytechinus variegatus. There was a significant correlation between both toxicity test results and un-ionized ammonia. Un-ionized ammonia concentrations, which could be responsible for the toxic effects, were higher in all interstitial samples when compared with sediment/water interface. It was conducled that the use of the sediment/water interface toxicity test can minimize the ammonia influence and more toxicity test results could be used. A significative correlation between PAHs in the whole sediment and the toxicity observed on interstitial water was shown. For metals the correlation occurred with sediment/water interface. There was no correlation between grain size and both toxicity test. It was possible to know about the toxicity (presence or absence) and classify the toxic samples in terms of toxic effects with the different stages of L. variegatus.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2015-11-20T14:21:24Z No. of bitstreams: 1 texto completo.pdf: 842879 bytes, checksum: ec6832f526e86a7088e77bc6568a1ec8 (MD5) / Made available in DSpace on 2015-11-20T14:21:24Z (GMT). No. of bitstreams: 1 texto completo.pdf: 842879 bytes, checksum: ec6832f526e86a7088e77bc6568a1ec8 (MD5) Previous issue date: 2015-03-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A redução dos ambientes naturais tem feito com que cada vez mais animais silvestres sejam encontrados em áreas urbanas, como praças e parques. Dentre essas espécies algumas populações de bichos preguiça já foram descritas por sua localização em centros urbanos. Existem poucos estudos com essa espécie, principalmente pelo fato de serem de difícil localização e observação em seus habitats naturais. Assim, estudar animais de áreas urbanas é interessante por fornecer dados importantes para o conhecimento de seus parâmetros biológicos. Embora a interação entre animais silvestres e humanos em áreas urbanas seja cada vez mais frequente, pouco se sabe sobre como ocorre esta interação e como os seres humanos avaliam a proximidade aos animais silvestres. Para tal, o presente trabalho entrevistou 182 pessoas na Praça Tiradentes de Teófilo Otoni, Minas Gerais e realizou análise do hemograma e bioquímico sanguíneo de preguiças viventes nas praças Tiradentes em Teófilo Otoni, Minas Gerais e João Pessoa, em Rio Tinto, Paraíba. As entrevistas indicaram que a população conhece pouco da biologia das preguiças e da população destes animais viventes na cidade. As interações, em sua maioria, são provocadas pelas pessoas, e as preguiças parecem não responder a esses contatos. Estudos sobre hematologia de animais silvestres são raros, mas essenciais para se conhecer melhor sobre as espécies, tornando-se possível o diagnóstico de doenças antes do aparecimento de sinais. Esse trabalho encontrou resultados hematológicos muito semelhantes aos descritos pela literatura, mesmo esses animais estando em ambientes urbanos e degradados. Alguns dos parâmetros bioquímicos (TGO e FA) diferiram em relação à literatura, que pode ser devido à dieta dos animais, que é menos diversificada do que daqueles de vida livre. Os resultados encontrados nesse estudo podem servir de base para outros estudos com a mesma espécie, ou até mesmo com espécies da mesma família. Entretanto, uma análise mais profunda do efeito da manutenção na área urbana na saúde destes animais é fundamental. / Habitat fragmentation has made growing the presence of wild animals in urban areas such as squares and parks. In some urban squares of Brazil, populations of sloths can be found. There are few studies on this species, mainly because they are difficult to locate and observation in dense woods. So studying animals in urban areas is interesting for providing important data for the knowledge of the species. Although the interaction between wild animals and human beings in urban areas is becoming common, this interaction is not well known and how humans beings evaluate the proximity to wildlife. This study interviewed 182 people in the Tiradentes‟s Square Teofilo Otoni, Minas Gerais and conducted analysis of blood count and blood biochemical sloths living in Tiradentes square in Teofilo Otoni, Minas Gerais and in João Pessoa square, in Rio Tinto, Paraíba. Interviews indicated that the population knows just a little bit of the biology of sloths and the population of these animals living in the city. Mostly of interactions are caused by people and sloths do not seem to respond to these contacts. Studies on wild animal hematology are rare but essential to know more about the species, and so it is possible to diagnose diseases before the onset of symptoms. This study found results very similar to those described in the literature hematological, even these animals being in urban and degraded environments. Some of the biochemical parameters (AST and AP) differed in the literature, which may be due to the animals' diet, which is less diverse than those animals that live in the wild. The results found in this study can serve as a basis for other studies of the same species, or even species of the same family. However, a deeper analysis of the effect of maintaining the urban area in the health of these animals was not possible.

The study of the process of speciation is instrumental to understanding the species diversity observed today. Diverging populations are intriguing, because speciation has not reached an endpoint, yet the process that may eventually lead to distinct species can be studied. Systems that contain many putative species and/or parallel divergences, such as many species flocks and species pairs, are extraordinary examples of divergence and therefore are critical to the understanding of the speciation process. A "miniature" species flock of pupfish (Cyprinodon variegatus) discovered in lakes on San Salvador Island, Bahamas has evolved in less than 6 000 years, and is, therefore, important to the study of the pace of evolutionary processes. The San Salvador Island pupfish flock is composed of a normal form, which resembles coastal C. variegatus, and bulldog and bozo morphs, which diverge ecologically and morphologically from the normal morph. In Chapter 1, I sequenced the mtDNA control region and used haplotype frequency analyses to assess the level of differentiation between sympatric normals and bulldogs sampled from Osprey Lake and Little Lake on San Salvador Island. The bozo morph was too rare to include in the study. I also included samples of normals that occur in lakes without bulldog and bozo morphs to assess any differences between lakes on the island. All haplotype frequency comparisons for sympatric normals and bulldogs were highly significant, which suggests these morphs are distinct populations in sympatry and, therefore, have characteristics of biological species. Further, an estimation of Time for Speciation supports geological data that suggest this fauna is very young (6 000 years). The San Salvador Island pupfish species flock is, therefore, the youngest known species flock and presents an important model system for the study of how morphological and ecological divergence can promote speciation in Cyprinodon. In Chapter 2, I first compared the San Salvador Island pupfishes to other Bahamian C. variegatus populations to assess the level of inter- and intra-island pupfish population differentiation in the Bahamas. The mtDNA control region was sequenced for bulldogs and normals from San Salvador Island and normals sampled from New Providence and Exuma Islands. San Salvador Island bulldogs were found to be distinct from all normal populations sampled, and comparisons of shared haplotypes suggest they originated on San Salvador Island rather than any of the other islands sampled. This was intriguing, because a "bulldog-like" morph has recently been observed in a lake on New Providence Island, which suggests parallel divergences may be occurring throughout the Bahamas. I also sequenced the mtDNA cytochrome b gene to assess the phylogeography of C. variegatus. Populations were sampled from the Bahamas and the east coast of North America, and the results suggest the Bahamas were only recently colonized by the Southern coastal lineage of C. variegatus. A distinct Northern lineage of C. variegatus, which may warrant species designation, was also supported by the cytochrome b data. Overall, the results supported a San Salvador Island origin for the Little Lake and Osprey Lake bulldog morphs, and also suggest the Bahamian C. variegatus populations are very young. / Master of Science

Existing ecotoxicity data for chemicals vary to a high extent between the environmental compartments water and sediment, since the evaluation of contaminants has historically focused on water exposition. Many anthropogenic chemicals and waste materials, including toxic organic and inorganic chemicals, adsorb to particulate matter and accumulate in sediments, and may thus be a threat to organisms living in the sediment. The invertebrates Chironomus riparius and Lumbriculus variegatus were selected as representatives of endobenthic living organisms. Acute toxicity tests, via water-only exposure, and sediment toxicity tests were conducted with the two endobenthic invertebrates. In sediment toxicity tests, organisms are mainly exposed to sediment- and particle-bound chemicals and dissolved chemical in the pore water. Toxicity data for algae, daphnids, and fish (via water-only exposure) are available for many substances, whereas the existing sediment toxicity data are rather rare. Thus, the interest arises to predict sediment toxicity for sediment-dwelling invertebrates from existing acute toxicity data of tests with water-only exposure. The main emphasis of this work was placed on one metal compound and seven organic chemicals. The objective of this study was fivefold: (1) develop methods and improve existing procedures on acute and sediment toxicity testing of the two invertebrates; (2) conduct both acute toxicity tests via water exposure and long-term sediment toxicity tests for the selected model substances to generate data for comparative discussion; (3) assess correlations among acute toxicity data of the organisms exposed via water-only and correlations among sediment toxicity data of the two endobenthic invertebrates for the eight tested chemicals; (4) assess possible forecasting for sediment toxicity from acute toxicity (via water-only exposure) and (5) assess exposure effects to determine the main exposure route. Acute toxicity data of the eight tested chemicals of D. magna significantly correlated with data of L. variegatus and C. riparius (p<0.05). However, a prediction of toxicity based on D. magna data bears high uncertainty, due to the small data set and high variation in sensitivity of the organisms. Existing sediment toxicity test methods were improved to meet the demand for artificial sediments containing organic matter that serves sufficiently as internal food source for the test organisms, and thus representing natural exposure conditions. However, the sediments that were used for the two organisms to test the selected model substances differed in sediment composition. Therefore, a sediment with the same sediment composition and the same water-to-sediment ratio for both invertebrates was developed, to have similar exposure conditions. In sediment toxicity tests, C. riparius was observed to be more sensitive than L. variegatus and no correlation was observed among data of the invertebrates. For the selected substances, lowest effect concentrations were observed for 3,4-dichloroaniline, whereas effect concentrations were the highest for benzo[a]pyrene. No correlations were found between the acute toxicity data of exposure via the water phase and sediment toxicity data, thus making a prediction of sediment toxicity data impossible. From analytical measurements of chemicals concentration in the compartments overlying, pore water, and bulk sediment, partition coefficients on sediment water partitioning were calculated. The highest partition coefficient ratios for sediment water partitioning were found for the high lipophilic organic substances 4,4-dichlorodiphenyltrichloroethan (DDT) and benzo[a]pyrene. Further, it was found that the main exposure routes in the 28-day sediment toxicity tests were not only chemical but species-dependent. As a result of very differing exposure routes for the tested chemicals and the absence of correlations from the acute to sediment toxicity data, sediment toxicity tests are necessary to assess the toxicity of chemicals on sediment inhabiting organisms. / In den meisten standardisierten ökotoxikologischen Untersuchungen zur Abschätzung des Gefährdungspotentials von Chemikalien für Gewässer erfolgt die Exposition der Organismen über die Wasserphase. Viele Schadstoffe, die in die aquatische Umwelt gelangen, adsorbieren aufgrund ihrer physikalisch-chemischen Eigenschaften an die Oberflächen von Schwebstoffen, sedimentieren und erreichen Sedimentkonzentrationen, die möglicherweise eine Gefahr für sedimentbewohnende Organismen darstellen. Im Rahmen dieser Arbeit wurden für benthische Invertebraten Testverfahren etabliert, bei denen eine Exposition der Organismen über das Sediment, hier hauptsächlich über die an ingestierte Sedimentbestandteile gebundene oder über die im Porenwasser gelöste Chemikalie (28-Tage Sedimenttoxizitätstest), und über dieWasserphase (Akuttoxizitätstest) erfolgte. Die Invertebraten Chironomus riparius und Lumbriculus variegatus wurden als typische Vertreter endobenthischer Organismen ausgewählt. Für viele Chemikalien liegen Daten zur akuten Toxizität für Algen, Daphnien und Fische für die Wasserexposition vor. Demgegenüber sind nur wenige Daten zur Toxizität für benthische Organismen weder mit einer Wasser- noch mit einer Sedimentexposition vorhanden. Als Modellsubstanzen wurden eine anorganische und sieben organische Substanzen für die Untersuchungen ausgewählt. Ziele dieser Arbeit waren: (1) die Entwicklung und Verbesserung von bestehenden Methoden zur Bestimmung der akuten Toxizität mitWasserexposition und der Sedimenttoxizität für die beiden Invertebraten; (2) die Durchführung der Tests mit den acht ausgewählten Modellsubstanzen zur vergleichenden Betrachtung; (3) die Beurteilung einer Korrelation der Daten zur Akuttoxizität innerhalb der verschiedenen Organismen mit Wasserexposition und einer Korrelation der Daten zwischen den beiden benthischen Organismen bei Sedimentexposition; (4) die Beurteilung einer Korrelation zwischen Daten der benthischen Invertebraten zur Akuttoxizität mit Wasserexposition und Sedimenttoxizität und (5) die Ermittlung und Bewertung der Expositionspfade. Die Akuttoxizitätsdaten von D. magna korrelieren significant (p<0.05) mit den Daten der beiden Invertebraten. Jedoch ist eine Vorhersage aufgrund des kleinen Datensatzes und der großen Unterschiede in der Empfindlichkeit der Arten abzulehnen. Um einer möglichst natürlichen Expositionssituation in Sedimenten zu entsprechen, wurden künstliche Sedimente mit interner Futterquelle, die auch mit der zu testenden Chemikalie kontaminiert wurde, entwickelt und für die Tests mit den Modellsubstanzen verwendet. Ein Nachteil war die unterschiedliche Sedimentzusammensetzung für die beiden Organismen. Um gleiche Expositionsbedingungen für beide Testorganismen zu gewährleisten, wurde ein artifizielles Sediment mit gleicher Zusammensetzung und gleichem Volumenverhältnis zwischen Sediment und Überstandswasser entwickelt. In den Sedimenttoxizitätstests reagierte C. riparius empfindlicher als L. variegatus. Die Effektkonzentrationen waren am niedrigsten für 3,4-Dichloraniline und am höchsten für Benzo[a]pyren. Die Korrelationen zwischen den Ergebnissen aus Akut- und Sedimenttoxizitstests waren nicht signifikant (p>0.05). Folglich läßt sich die Sedimenttoxizität nicht aus Daten zur akuten Toxizität mit Wasserexposition abschätzen. Aus den analytischen Messungen von Sediment-, Porenwasser- und Überstandswasserproben wurden die Koeffizienten für die Verteilung zwischen Sediment und Wasser berechnet. Für die stark lipophilen Stoffe, 4-Dichlorodiphenyltrichloroethan (DDT) und Benzo[a]pyren wurden die höchsten Koeffizienten errechnet. Weiterhin wurde festgestellt, daß die Hauptexpositionspfade in Sedimenttoxizitätstests einerseits von der Chemikalie und andererseits von der verwendeten Spezies abhängen. Aufgrund der Ergebnisse dieser Arbeit und der Tatsache, daß Sedimente “Senken” für viele Schadstoffe sind, müssen zur Erfassung und Bewertung des Gefährdungspotentials von Chemikalien gegenüber Sedimentbewohnern weiterhin Sedimenttoxizitätstests durchgeführt werden.

Existing ecotoxicity data for chemicals vary to a high extent between the environmental compartments water and sediment, since the evaluation of contaminants has historically focused on water exposition. Many anthropogenic chemicals and waste materials, including toxic organic and inorganic chemicals, adsorb to particulate matter and accumulate in sediments, and may thus be a threat to organisms living in the sediment. The invertebrates Chironomus riparius and Lumbriculus variegatus were selected as representatives of endobenthic living organisms. Acute toxicity tests, via water-only exposure, and sediment toxicity tests were conducted with the two endobenthic invertebrates. In sediment toxicity tests, organisms are mainly exposed to sediment- and particle-bound chemicals and dissolved chemical in the pore water. Toxicity data for algae, daphnids, and fish (via water-only exposure) are available for many substances, whereas the existing sediment toxicity data are rather rare. Thus, the interest arises to predict sediment toxicity for sediment-dwelling invertebrates from existing acute toxicity data of tests with water-only exposure. The main emphasis of this work was placed on one metal compound and seven organic chemicals. The objective of this study was fivefold: (1) develop methods and improve existing procedures on acute and sediment toxicity testing of the two invertebrates; (2) conduct both acute toxicity tests via water exposure and long-term sediment toxicity tests for the selected model substances to generate data for comparative discussion; (3) assess correlations among acute toxicity data of the organisms exposed via water-only and correlations among sediment toxicity data of the two endobenthic invertebrates for the eight tested chemicals; (4) assess possible forecasting for sediment toxicity from acute toxicity (via water-only exposure) and (5) assess exposure effects to determine the main exposure route. Acute toxicity data of the eight tested chemicals of D. magna significantly correlated with data of L. variegatus and C. riparius (p<0.05). However, a prediction of toxicity based on D. magna data bears high uncertainty, due to the small data set and high variation in sensitivity of the organisms. Existing sediment toxicity test methods were improved to meet the demand for artificial sediments containing organic matter that serves sufficiently as internal food source for the test organisms, and thus representing natural exposure conditions. However, the sediments that were used for the two organisms to test the selected model substances differed in sediment composition. Therefore, a sediment with the same sediment composition and the same water-to-sediment ratio for both invertebrates was developed, to have similar exposure conditions. In sediment toxicity tests, C. riparius was observed to be more sensitive than L. variegatus and no correlation was observed among data of the invertebrates. For the selected substances, lowest effect concentrations were observed for 3,4-dichloroaniline, whereas effect concentrations were the highest for benzo[a]pyrene. No correlations were found between the acute toxicity data of exposure via the water phase and sediment toxicity data, thus making a prediction of sediment toxicity data impossible. From analytical measurements of chemicals concentration in the compartments overlying, pore water, and bulk sediment, partition coefficients on sediment water partitioning were calculated. The highest partition coefficient ratios for sediment water partitioning were found for the high lipophilic organic substances 4,4-dichlorodiphenyltrichloroethan (DDT) and benzo[a]pyrene. Further, it was found that the main exposure routes in the 28-day sediment toxicity tests were not only chemical but species-dependent. As a result of very differing exposure routes for the tested chemicals and the absence of correlations from the acute to sediment toxicity data, sediment toxicity tests are necessary to assess the toxicity of chemicals on sediment inhabiting organisms. / In den meisten standardisierten ökotoxikologischen Untersuchungen zur Abschätzung des Gefährdungspotentials von Chemikalien für Gewässer erfolgt die Exposition der Organismen über die Wasserphase. Viele Schadstoffe, die in die aquatische Umwelt gelangen, adsorbieren aufgrund ihrer physikalisch-chemischen Eigenschaften an die Oberflächen von Schwebstoffen, sedimentieren und erreichen Sedimentkonzentrationen, die möglicherweise eine Gefahr für sedimentbewohnende Organismen darstellen. Im Rahmen dieser Arbeit wurden für benthische Invertebraten Testverfahren etabliert, bei denen eine Exposition der Organismen über das Sediment, hier hauptsächlich über die an ingestierte Sedimentbestandteile gebundene oder über die im Porenwasser gelöste Chemikalie (28-Tage Sedimenttoxizitätstest), und über dieWasserphase (Akuttoxizitätstest) erfolgte. Die Invertebraten Chironomus riparius und Lumbriculus variegatus wurden als typische Vertreter endobenthischer Organismen ausgewählt. Für viele Chemikalien liegen Daten zur akuten Toxizität für Algen, Daphnien und Fische für die Wasserexposition vor. Demgegenüber sind nur wenige Daten zur Toxizität für benthische Organismen weder mit einer Wasser- noch mit einer Sedimentexposition vorhanden. Als Modellsubstanzen wurden eine anorganische und sieben organische Substanzen für die Untersuchungen ausgewählt. Ziele dieser Arbeit waren: (1) die Entwicklung und Verbesserung von bestehenden Methoden zur Bestimmung der akuten Toxizität mitWasserexposition und der Sedimenttoxizität für die beiden Invertebraten; (2) die Durchführung der Tests mit den acht ausgewählten Modellsubstanzen zur vergleichenden Betrachtung; (3) die Beurteilung einer Korrelation der Daten zur Akuttoxizität innerhalb der verschiedenen Organismen mit Wasserexposition und einer Korrelation der Daten zwischen den beiden benthischen Organismen bei Sedimentexposition; (4) die Beurteilung einer Korrelation zwischen Daten der benthischen Invertebraten zur Akuttoxizität mit Wasserexposition und Sedimenttoxizität und (5) die Ermittlung und Bewertung der Expositionspfade. Die Akuttoxizitätsdaten von D. magna korrelieren significant (p<0.05) mit den Daten der beiden Invertebraten. Jedoch ist eine Vorhersage aufgrund des kleinen Datensatzes und der großen Unterschiede in der Empfindlichkeit der Arten abzulehnen. Um einer möglichst natürlichen Expositionssituation in Sedimenten zu entsprechen, wurden künstliche Sedimente mit interner Futterquelle, die auch mit der zu testenden Chemikalie kontaminiert wurde, entwickelt und für die Tests mit den Modellsubstanzen verwendet. Ein Nachteil war die unterschiedliche Sedimentzusammensetzung für die beiden Organismen. Um gleiche Expositionsbedingungen für beide Testorganismen zu gewährleisten, wurde ein artifizielles Sediment mit gleicher Zusammensetzung und gleichem Volumenverhältnis zwischen Sediment und Überstandswasser entwickelt. In den Sedimenttoxizitätstests reagierte C. riparius empfindlicher als L. variegatus. Die Effektkonzentrationen waren am niedrigsten für 3,4-Dichloraniline und am höchsten für Benzo[a]pyren. Die Korrelationen zwischen den Ergebnissen aus Akut- und Sedimenttoxizitstests waren nicht signifikant (p>0.05). Folglich läßt sich die Sedimenttoxizität nicht aus Daten zur akuten Toxizität mit Wasserexposition abschätzen. Aus den analytischen Messungen von Sediment-, Porenwasser- und Überstandswasserproben wurden die Koeffizienten für die Verteilung zwischen Sediment und Wasser berechnet. Für die stark lipophilen Stoffe, 4-Dichlorodiphenyltrichloroethan (DDT) und Benzo[a]pyren wurden die höchsten Koeffizienten errechnet. Weiterhin wurde festgestellt, daß die Hauptexpositionspfade in Sedimenttoxizitätstests einerseits von der Chemikalie und andererseits von der verwendeten Spezies abhängen. Aufgrund der Ergebnisse dieser Arbeit und der Tatsache, daß Sedimente “Senken” für viele Schadstoffe sind, müssen zur Erfassung und Bewertung des Gefährdungspotentials von Chemikalien gegenüber Sedimentbewohnern weiterhin Sedimenttoxizitätstests durchgeführt werden.