Wastewaters from rural sewage lagoons in Manitoba contain pharmaceuticals that are potentially harmful to non-target organisms and reduce overall water quality when released. An option for reducing exposure to wastewater contaminants and potential toxicity is surface flow treatment wetlands. However, little is known of the fate of pharmaceuticals in these types of systems. The fate and effects of six pharmaceuticals (carbamazepine, clofibric acid, fluoxetine, naproxen, sulfamethoxazole, sulfapyridine) were assessed in mesocosms simulating treatment wetlands in two separate 28-day experiments in the summer and fall of 2011, respectively: with and without significant aquatic plant communities, and with additional nutrients and harvesting of biomass. The removal of pharmaceuticals had half-lives that ranged from 0.23 to 9.4 days and 1.4 to 18 days during the summer and fall, respectively, and were predicted to occur primarily through photolysis and sorption. No overt toxicity from pharmaceuticals was observed for the common wetland macrophytes Myriophyllum sibiricum and Typha spp., but there was partitioning and bioaccumulation into macrophyte biomass. Treatment wetlands appeared to reduce pharmaceuticals and nutrients adequately, and may be a cost-effective means of treating rural wastewater.

Wastewaters from rural sewage lagoons in Manitoba contain pharmaceuticals that are potentially harmful to non-target organisms and reduce overall water quality when released. An option for reducing exposure to wastewater contaminants and potential toxicity is surface flow treatment wetlands. However, little is known of the fate of pharmaceuticals in these types of systems. The fate and effects of six pharmaceuticals (carbamazepine, clofibric acid, fluoxetine, naproxen, sulfamethoxazole, sulfapyridine) were assessed in mesocosms simulating treatment wetlands in two separate 28-day experiments in the summer and fall of 2011, respectively: with and without significant aquatic plant communities, and with additional nutrients and harvesting of biomass. The removal of pharmaceuticals had half-lives that ranged from 0.23 to 9.4 days and 1.4 to 18 days during the summer and fall, respectively, and were predicted to occur primarily through photolysis and sorption. No overt toxicity from pharmaceuticals was observed for the common wetland macrophytes Myriophyllum sibiricum and Typha spp., but there was partitioning and bioaccumulation into macrophyte biomass. Treatment wetlands appeared to reduce pharmaceuticals and nutrients adequately, and may be a cost-effective means of treating rural wastewater.

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As atividades agrícolas, principalmente as monoculturas, exigem grande utilização de insumos. A aplicação constante de defensivos agrícolas, como herbicidas, pesticidas e fungicidas, tem promovido crescentes impactos sobre os recursos hídricos e biota neles presentes, principalmente em organismos não alvo dessas substâncias. O presente estudo teve como principal objetivo avaliar os efeitos do fungicida Pyrimethanil na comunidade de macroinvertebrados bentônicos, por meio do monitoramento ambiental em unidades experimentais de campo (mesocosmos) e ensaios ecotoxicológicos laboratoriais com indivíduos da espécie Chironomus sancticaroli. Os mesocosmos foram construídos utilizando-se seis caixas de água com volume equivalente a 1500 litros. A contaminação dos mesocosmos com Pyrimethanil foi realizada por meio de pulverização direta na superfície da água aplicando-se uma concentração equivalente a 0,1 mg/L de Pyrimethanil nos mesocosmos contaminados. Dessa maneira, os mesocosmos foram divididos em três réplicas contaminadas e três réplicas controles. O monitoramento e coleta de amostras de água e macroinvertebrados bentônicos foram realizados com frequência mensal, durante o período de um ano. O fungicida Pyrimethanil não ocasionou alterações significativas nas variáveis monitoradas. Da mesma forma, a estrutura comunitária de macroinvertebrados bentônicos apresentou características semelhantes entre os mesocosmos contaminados e controles. Entretanto, durante o monitoramento, os mesocosmos controles apresentaram valores significativamente mais elevados na abundância de indivíduos e quantidade total de táxons quando comparados aos valores observados nos mesocosmos contaminados com Pyrimethanil. / Agricultural activities, mainly monocultures, require large use of inputs. The constant application of agrochemicals, as herbicides, pesticides and fungicides, has promoted impacts on water resources and biota at the center, especially on non-target organisms such substances. This study aimed to evaluate the effects of fungicide Pyrimethanil in benthic macroinvertebrate community through environmental monitoring experimental units of field (mesocosms) and laboratory ecotoxicological tests with individuals of Chironomus sancticaroli. The mesocosms were made using six tanks with maximum volume equivalent to 1500 liters. The contamination of the tanks with Pyrimethanil was performed by spraying of water on the surface by applying a fungicide concentration equivalent to 0,1 mg/L. Thus, the mesocosms were divided into three contaminated replicas and three controls replicas. The monitoring and sampling of water and benthic macroinvertebrates were performed on a monthly basis during the period of one year. The fungicide Pyrimethanil does not cause significant changes in monitored variables. Similarly, the community structure of benthic macroinvertebrates were similar characteristics between the contaminated and control mesocosms. However, during the monitoring, the mesocosms controls had significantly higher values in the abundance of individuals and total number of taxa compared to the values observed in the mesocosms contaminated with Pyrimethanil.

Habitat modification is the primary cause of amphibian population declines worldwide. Some species survive in modified habitats whereas others become restricted to small, isolated forest patches. Although many studies compare species richness and composition between modified and intact habitats, the factors and mechanisms that maintain biodiversity in these landscapes are poorly understood. I asked how life history traits and habitat features influence interspecific variation in frog occupancy patterns in tropical pasture and forest. To identify mechanisms underlying occupancy patterns, I used experiments to examine how abiotic conditions in different habitats influence the vital rates of tadpoles. I also explored whether tadpoles use a carnivorous foraging strategy to improve performance in nutrient-poor, ephemeral pools in pasture. Although modified and intact habitats offer abiotic environments that differ in quality for frogs, pastures contribute to the maintenance of biodiversity in fragmented landscapes. I detected an equal number of species but substantially different assemblage composition in forest and pasture. Species that occurred in pasture had different traits than those in forest, including larger body sizes, larger clutch sizes, larger geographic ranges, and reproductive modes that depend on water. The occurrence of pasture-specialists was associated with habitat features at small spatial scales, whereas the occurrence of forest-specialists was associated with habitat features at small and large spatial scales. An experiment indicated that abiotic conditions in pastures may deter or facilitate adult movements to breeding sites. Behavioral selection of sites by two model species was consistent with tadpole performance. Tadpoles of a pasture-specialist performed well across the pasture-forest gradient, but abiotic conditions in pasture facilitated faster growth and development than in edge or forest. In contrast, tadpoles of a forest-specialist performed well only in edge and forest. Most tadpoles occupying ephemeral pasture pools were facultative carnivores or cannibals of eggs and hatchlings. Tadpoles may contribute to the regulation of assemblages in pasture pools, influencing the relative abundance and composition of species through differential predation on eggs and hatchlings. The study of factors and mechanisms that contribute to population growth or decline of species can facilitate understanding of assemblage-level patterns of amphibian diversity in modified landscapes.

Tradtional brominated flame retardants (BFRs), namely the polybrominated diphenyl ethers (PBDEs), have persistent, bioaccumulative, and toxic properties that have resulted in the phase out of their production and their be banned in certain jurisdictions. To meet regulatory flame retardancy requirements, non-PBDE BFRs have entered the marketplace. Much remains unknown regarding the environmental fate and toxicity of these emerging BFRs. The objective of this thesis was to use outdoor mesocosms to examine the fate and toxicity of three emerging BFRs; bis(tribromophenoxy)ethane (BTBPE), tetrabromobisphenol A bis(dibromopropyl ether) (TBBPA-DBPE), and BZ-54, which consists of two BFRs, ethylhexyl-tetrabromobenzoate (EHTeBB) and bis(ethylhexyl)tetrabromophthalate (BEHTBP). While it was difficult to accurately determine degradation rates because of fluctuating concentrations, the estimated half-lives indicated these compounds are persistent (> 60 days in sediments). The partitioning of the compounds between the particulates and the sediment resulted in differential degradation rates (greater in the particulates), and products formed; those formed on the particulates were consistent with photodegradation products. The effects of these emerging BFRs on Hyalella azteca and the benthic macroinvertebrate community were assessed through the use of in situ exposure and sampling techniques. The in situ Hyalella cages showed a high degree of variability for most endpoints, regardless of their placement (e.g., water column vs. sediment) in the mesocosm. BTBPE accumulated in the H. azteca (0.03 – 1.4 ng/g ww), however this was not associated with any changes in growth or reproduction. There was high variability in abundance and diversity between the mesocosms, which limited the ability to detect statistically significant differences. Interestingly, the BZ-54 treated mesocosms had the greatest abundance, and the least amount of community diversity. This thesis examined the bioaccumulation potential of these compounds in fathead minnow (Pimephales promelas), as well as the associated effects on growth and development as measured through physical and biochemical endpoints. There was considerable uptake and persistence of BTBPE and TBBPA-DBPE, as well as indication of metabolism of these compounds, but limited physical effects observed. There were indications of increased oxidative stress in the BZ-54 treatment, and increased induction of vitellogenin in fathead minnow from the BTBPE treatment. / Environment Canada's Chemicals Management Plan

As atividades agrícolas, principalmente as monoculturas, exigem grande utilização de insumos. A aplicação constante de defensivos agrícolas, como herbicidas, pesticidas e fungicidas, tem promovido crescentes impactos sobre os recursos hídricos e biota neles presentes, principalmente em organismos não alvo dessas substâncias. O presente estudo teve como principal objetivo avaliar os efeitos do fungicida Pyrimethanil na comunidade de macroinvertebrados bentônicos, por meio do monitoramento ambiental em unidades experimentais de campo (mesocosmos) e ensaios ecotoxicológicos laboratoriais com indivíduos da espécie Chironomus sancticaroli. Os mesocosmos foram construídos utilizando-se seis caixas de água com volume equivalente a 1500 litros. A contaminação dos mesocosmos com Pyrimethanil foi realizada por meio de pulverização direta na superfície da água aplicando-se uma concentração equivalente a 0,1 mg/L de Pyrimethanil nos mesocosmos contaminados. Dessa maneira, os mesocosmos foram divididos em três réplicas contaminadas e três réplicas controles. O monitoramento e coleta de amostras de água e macroinvertebrados bentônicos foram realizados com frequência mensal, durante o período de um ano. O fungicida Pyrimethanil não ocasionou alterações significativas nas variáveis monitoradas. Da mesma forma, a estrutura comunitária de macroinvertebrados bentônicos apresentou características semelhantes entre os mesocosmos contaminados e controles. Entretanto, durante o monitoramento, os mesocosmos controles apresentaram valores significativamente mais elevados na abundância de indivíduos e quantidade total de táxons quando comparados aos valores observados nos mesocosmos contaminados com Pyrimethanil. / Agricultural activities, mainly monocultures, require large use of inputs. The constant application of agrochemicals, as herbicides, pesticides and fungicides, has promoted impacts on water resources and biota at the center, especially on non-target organisms such substances. This study aimed to evaluate the effects of fungicide Pyrimethanil in benthic macroinvertebrate community through environmental monitoring experimental units of field (mesocosms) and laboratory ecotoxicological tests with individuals of Chironomus sancticaroli. The mesocosms were made using six tanks with maximum volume equivalent to 1500 liters. The contamination of the tanks with Pyrimethanil was performed by spraying of water on the surface by applying a fungicide concentration equivalent to 0,1 mg/L. Thus, the mesocosms were divided into three contaminated replicas and three controls replicas. The monitoring and sampling of water and benthic macroinvertebrates were performed on a monthly basis during the period of one year. The fungicide Pyrimethanil does not cause significant changes in monitored variables. Similarly, the community structure of benthic macroinvertebrates were similar characteristics between the contaminated and control mesocosms. However, during the monitoring, the mesocosms controls had significantly higher values in the abundance of individuals and total number of taxa compared to the values observed in the mesocosms contaminated with Pyrimethanil.

O objetivo geral do trabalho foi avaliar a distribuição e os efeitos tóxicos dos metais Cr e Cu sobre os ecossistemas aquáticos lênticos, incluindo seus componentes bióticos e abióticos, utilizando-se sistemas com diferentes níveis de complexidade e organização. Os sistemas utilizados na avaliação da toxicidade de Cr e Cu foram: a) testes uniespecíficos com Selenastrum capricornutum (microalga), Daphnia similis e Ceriodaphnia dubia (Cladocera), Chironomus xanthus (Diptera, Chironomidae), Oreochromis niloticus (peixe) e Pistia stratiotes (macrófita); b) experimentos em microcosmos (testes multiespecíficos) com as comunidades naturais da represa do Lobo; c) experimentos em mesocosmos, contando com água, sedimento, plâncton, bentos, peixes e macrófitas naturais da represa do Lobo. Nos testes de toxicidade todas as espécies foram mais sensíveis ao Cu que ao Cr, e a sequência de sensibilidade foi D. similis> C. dubia> S. capricornutum> C. xanthus > P. stratiotes > O. niloticus. Nos experimentos em microcosmos e mesocosmos, as concentrações-teste foram definidas como o valor máximo permitido pela Resolução nº 20/1986 do CONAMA para Cr6+ e Cu2+ para corpos dágua Classe 2 (50 µg.L-1 e 20 µg.L-1, respectivamente). Em todos os experimentos a concentração de clorofila foi reduzida significativamente após a adição dos metais. Os efeitos sobre a densidade e riqueza de espécies das comunidades zooplanctônicas foram mais severos para o Cr que para o Cu; porém Cladocera foi mais sensível ao Cu. Cromo provocou uma maior inibição na produção primária em abril de 2002, enquanto que em novembro/dezembro de 2002 a produção primária sofreu maior decréscimo após a adição de Cu. Ambos os metais estudados apresentaram efeitos significativos sobre um grande número de variáveis da água, como oxigênio dissolvido, amônio, distribuição das formas fosfatadas, clorofila e material em suspensão, sendo os efeitos do Cr mais severos que os do Cu, em relação ao número de variáveis afetadas e ao tempo de restauração do sistema. Os sedimentos não apresentaram alterações após a adição de metais. Foi observada a ocorrência de bioacumulação de Cr e Cu pelo plâncton, bentos, macrófitas e peixes. A toxicidade dos metais estudados foi reduzida após a inclusão de peixes e macrófitas, principalmente para Cu. Apesar das concentrações de Cr e Cu relativamente baixas empregadas, os metais provocaram efeitos nos compartimentos bióticos e abióticos do sistema. Os resultados obtidos no presente trabalho podem ser úteis como subsídio para a avaliação dos valores máximos permitidos pela Resolução nº 20/1986 do CONAMA para os metais estudados. / The general aim of this work was to evaluate the distribution and the toxic effects of the metals Cr and Cu on lenthic aquatic ecosystems, using systems of different complexity and organization levels. The systems used for Cr and Cu toxicity evaluations were: a) single-specific tests with Selenastrum capricornutum (microalgae), Daphnia similis e Ceriodaphnia dubia (Cladocera), Chironomus xanthus (Diptera, Chironomidae), Oreochromis niloticus (fish) and Pistia stratiotes (macrophyte); b) microcosms experiments (multi- specific tests) with the Lobos reservoir natural communities; c) mesocosms experiments, with natural water, sediment, plankton, benthics, fishes and macrophytes from Lobos reservoir. In the toxicity tests, all the species were more sensitive to Cu than to Cr, and the sensitiviness sequence was D. similis> C. dubia> S. capricornutum> C. xanthus > P. stratiotes > O. niloticus. In the microcosms and mesocosms experiments, the test-concentrations were the maximum value allowed by the CONAMA Resolution nº 20/1986 to Cr6+ and Cu2+ to Class 2 water bodies (50 µg.L-1 and 20 µg.L-1, respectively). In all experiments the chlorophyll concentration was significantly reduced after the metal addition. The effects on the Zooplankton density and richness were stronger to Cr than to Cu; however Cladocera was more sensitive to Cu. Chromium caused higher inhibition in primary production in April/ 2002, but in November/ December 2002 the primary production suffered higher inhibition by Cu addition. Both studied metals showed significant effects on several water variables, as dissolved oxygen, ammonium, phosphate forms distribution, chlorophyll and suspended material, being the Cr effects stronger than the Cu effects, in relation to the number of affected variables and the system restoration time. The sediments didnt show alterations after the metal addition. Chromium and Cu bioaccumulation was observed by plankton, benthic invertebrates, macrophytes and fishes. The toxicity of the studied metals was reduced by the fish and macrophyte inclusion, mainly to Cu. Although the concentration of Cr and Cu were low, toxic effects were observed on both biotic and abiotic system compartments. The results obtained in this work may be useful as subsidy to evaluation of the maximum value allowed by the CONAMA Resolution nº 20/1986 to the studied metals.

O objetivo geral do trabalho foi avaliar a distribuição e os efeitos tóxicos dos metais Cr e Cu sobre os ecossistemas aquáticos lênticos, incluindo seus componentes bióticos e abióticos, utilizando-se sistemas com diferentes níveis de complexidade e organização. Os sistemas utilizados na avaliação da toxicidade de Cr e Cu foram: a) testes uniespecíficos com Selenastrum capricornutum (microalga), Daphnia similis e Ceriodaphnia dubia (Cladocera), Chironomus xanthus (Diptera, Chironomidae), Oreochromis niloticus (peixe) e Pistia stratiotes (macrófita); b) experimentos em microcosmos (testes multiespecíficos) com as comunidades naturais da represa do Lobo; c) experimentos em mesocosmos, contando com água, sedimento, plâncton, bentos, peixes e macrófitas naturais da represa do Lobo. Nos testes de toxicidade todas as espécies foram mais sensíveis ao Cu que ao Cr, e a sequência de sensibilidade foi D. similis> C. dubia> S. capricornutum> C. xanthus > P. stratiotes > O. niloticus. Nos experimentos em microcosmos e mesocosmos, as concentrações-teste foram definidas como o valor máximo permitido pela Resolução nº 20/1986 do CONAMA para Cr6+ e Cu2+ para corpos dágua Classe 2 (50 µg.L-1 e 20 µg.L-1, respectivamente). Em todos os experimentos a concentração de clorofila foi reduzida significativamente após a adição dos metais. Os efeitos sobre a densidade e riqueza de espécies das comunidades zooplanctônicas foram mais severos para o Cr que para o Cu; porém Cladocera foi mais sensível ao Cu. Cromo provocou uma maior inibição na produção primária em abril de 2002, enquanto que em novembro/dezembro de 2002 a produção primária sofreu maior decréscimo após a adição de Cu. Ambos os metais estudados apresentaram efeitos significativos sobre um grande número de variáveis da água, como oxigênio dissolvido, amônio, distribuição das formas fosfatadas, clorofila e material em suspensão, sendo os efeitos do Cr mais severos que os do Cu, em relação ao número de variáveis afetadas e ao tempo de restauração do sistema. Os sedimentos não apresentaram alterações após a adição de metais. Foi observada a ocorrência de bioacumulação de Cr e Cu pelo plâncton, bentos, macrófitas e peixes. A toxicidade dos metais estudados foi reduzida após a inclusão de peixes e macrófitas, principalmente para Cu. Apesar das concentrações de Cr e Cu relativamente baixas empregadas, os metais provocaram efeitos nos compartimentos bióticos e abióticos do sistema. Os resultados obtidos no presente trabalho podem ser úteis como subsídio para a avaliação dos valores máximos permitidos pela Resolução nº 20/1986 do CONAMA para os metais estudados. / The general aim of this work was to evaluate the distribution and the toxic effects of the metals Cr and Cu on lenthic aquatic ecosystems, using systems of different complexity and organization levels. The systems used for Cr and Cu toxicity evaluations were: a) single-specific tests with Selenastrum capricornutum (microalgae), Daphnia similis e Ceriodaphnia dubia (Cladocera), Chironomus xanthus (Diptera, Chironomidae), Oreochromis niloticus (fish) and Pistia stratiotes (macrophyte); b) microcosms experiments (multi- specific tests) with the Lobos reservoir natural communities; c) mesocosms experiments, with natural water, sediment, plankton, benthics, fishes and macrophytes from Lobos reservoir. In the toxicity tests, all the species were more sensitive to Cu than to Cr, and the sensitiviness sequence was D. similis> C. dubia> S. capricornutum> C. xanthus > P. stratiotes > O. niloticus. In the microcosms and mesocosms experiments, the test-concentrations were the maximum value allowed by the CONAMA Resolution nº 20/1986 to Cr6+ and Cu2+ to Class 2 water bodies (50 µg.L-1 and 20 µg.L-1, respectively). In all experiments the chlorophyll concentration was significantly reduced after the metal addition. The effects on the Zooplankton density and richness were stronger to Cr than to Cu; however Cladocera was more sensitive to Cu. Chromium caused higher inhibition in primary production in April/ 2002, but in November/ December 2002 the primary production suffered higher inhibition by Cu addition. Both studied metals showed significant effects on several water variables, as dissolved oxygen, ammonium, phosphate forms distribution, chlorophyll and suspended material, being the Cr effects stronger than the Cu effects, in relation to the number of affected variables and the system restoration time. The sediments didnt show alterations after the metal addition. Chromium and Cu bioaccumulation was observed by plankton, benthic invertebrates, macrophytes and fishes. The toxicity of the studied metals was reduced by the fish and macrophyte inclusion, mainly to Cu. Although the concentration of Cr and Cu were low, toxic effects were observed on both biotic and abiotic system compartments. The results obtained in this work may be useful as subsidy to evaluation of the maximum value allowed by the CONAMA Resolution nº 20/1986 to the studied metals.

With rising salinity levels in many freshwaters across the globe caused by for example sealevel rise and de-icing salts, it becomes important to understand what effect it has on freshwater ecosystems, since the lakes and rivers themselves are important parts in the global carbon cycle. In this study I have looked at what effects increased salinity levels have on different lakes metabolism, specifically oxygen concentration and primary production. The experiment was conducted using mesocosms in three different lakes in Sweden, separated both geographically and by nutrient status (eutrophic, oligotrophic, and dystrophic as well as oligotrophic). The response to increased salinity differed between the lakes; the increased salinity had a strong negative effect on the oligotrophic lake. In general, increased salinity caused a decline in oxygen content, both the maximum value and the amount of diurnal variation, as well as primary production. Therefore, the conclusion is that a rise in salinity will affect lake metabolism in a detrimental way, with a stronger effect on more sensitive lakes. / Med stigande saltnivåer i många sötvatten världen över, orsakade av exempelvis ökande havsnivåer och applicering av vägsalt, blir det viktigt att förstå vilken påverkan detta har på ekosystem i sötvatten då de utgör en viktig del I den globala kolcykeln. I den här studien har jag tittat på vilken effekt förhöjda salthalter har på olika sjöars metabolism, specifikt syrehalt och primärproduktion. Experimentet utfördes med hjälp av mesokosmer i tre olika svenska sjöar, skilda både geografiskt och trofiskt (eutrof, oligotrof samt dystrof och oligotrof). Sjöarnas respons till den ökade salthalten varierade; saltet hade en starkt negativ effekt på den oligotrofa sjön. På en generell nivå så sjönk syrehalten, både maximum värden och dygnsvariationen, samt primärproduktionen vid högre salthalter. Slutsatsen blir därför att ökade saltnivåer kommer att påverka sjöars metabolism negativt, med en starkare effekt på mer känsliga sjöar.