The dissertation thesis consists of five articles, bringing together results from investigations of macroinvertebrates in running waters. The use of freshwater macroinvertebrate organisms to assess environmental changes was based on the following facts: a) the presence/absence of taxa provide information about abiotic factors and/or about the pollution status of the site, b) they are indigenous and sedentary species, so that the environmental implications can be related to the site they live on, c) the organisms accumulate xenobiotic elements or compounds, thus reflecting the contaminant level in the environment. Localization of the sampling sites was related to the "hot-spots" of environmental problems. The particular investigations were carried out in the Elbe River catchment and in the Czech mountains on the selected headwater streams of the GEOMON network of the Czech Geological Survey. The Elbe was considered one of the most polluted rivers across Europe in the second half of the past century until the socio-economic transformation after 1989. The headwater streams in the Czech Republic were chosen with respect to the problem of acidification. The ability of bioaccumulation of xenobiotics in macroinvertebrate organisms was used to assess the long-term load of the Elbe ecosystem with trace...

Arctic ecosystems are amongst the most vulnerable on Earth to ongoing climate change. While the responses to these changes are well studied on land, less is known about how aquatic communities may respond to a warmer arctic. For stream invertebrate communities, predicting such responses requires basic understanding of how and why different taxonomic groups fluctuate throughout the year. However, few studies have assessed the community dynamics of stream macroinvertebrates across seasons in the Arctic. In this project, I asked how macroinvertebrate community structure changes between months and across seasons in a small Arctic stream in northern Sweden. I expected that community change over time would reflect changes in the supply of organic matter (e.g., leaf litter and algae) to dominant consumers. A total of five transects were sampled for macroinvertebrates each month from July to April using Surber sampling. I used descriptive and multivariate analyses to evaluate changes in community structure between months and seasons. Marked differences in community composition were found between the seasons with detritivores (shredders) dominating the autumn months possibly reflecting input of birch litter and high abundances of grazers during and post winter, possibly reflecting primary production early in spring. Expected climate change effects in the Arctic include warmer temperatures and increases in the terrestrial plant productivity. My results suggest that these shifts could cause changes in stream community composition, driven by increases in deciduous litter inputs that promote shredders and/or by increases in primary production during spring that favour grazers and collector-gatherers, which feed on algae.

Com o intuito de conhecer o histórico da comunidade bentônica no reservatório do Guarapiranga para futuro estudo sobre a influência das diferentes formas de poluição na represa sobre o zoobentos, este trabalho foi desenvolvido a fim de coletar dados históricos da fauna de fundo e se houve variação na estrutura da comunidade ou não. Foram analisados quatro trabalhos realizados no período de inverno em quatro regiões médio-profundal do reservatório (Guarapiranga, Embu-Mirim, Embu-Guaçu e Parelheiros) ao longo dos anos, 1939, 1976, 1996 e 2010. A riqueza de dados presentada nos trabalhos refletiu a evolução do conhecimento em estudos limnológicos no Brasil e no mundo. A densidade de Oligochaeta apresentou aumento ao longo dos anos, assim como a de Chaoboridae. Por outro lado, Chironomidae que apresentava 30% em 1974 é pouco representativo em 2010. O ambiente mostrou forte e crescente enriquecimento orgânico em todos os pontos ao longo dos anos e isso colaborou para uma maior diversidade de grupos detritívoros (Tubificinae e Naidinae - Oligochaeta), por exemplo. Os níveis de oxigênio dissolvido no fundo diminuíram ao longo dos anos em todos as regiões. Chama-se a atenção para a necessidade de biomonitoramento nas 4 regiões da represa, utilizando inclusive os macroinvertebrados bentônicos e análises físicas e químicas do sedimento e a adoção de uma nova forma de gerenciamento deste manancial / With the purpose to know the history of the benthic community in Guarapiranga reservoir for future study about the influence of different sources of pollution in the reservoir over zoobenthos, this study was conducted to collect historical data of benthic fauna and variation in community structure. Four studies conducted during winter in four regions of the reservoir medium-profundal (Guarapiranga, Embu-Mirim, Embu-Guaçu and Parelheiros) over the years, 1939, 1976, 1996 and 2010 were analysed. The best richness of data presented in the works reflected the evolution of knowledge in limnological studies, in Brazil and worldwide. The density of Oligochaeta had an increase over the years as well as the Chaoboridae. On the other hand, Chironomidae presented 30% in the 70\' community and was not representative anymore in 2010. The environment showed strong organic enrichment for all regions along the years, and this has contributed to a greater diversity of detritivorous groups (Tubificinae and Naidinae - Oligochaeta), for example. The dissolved oxygen levels at the bottom declined over the years in all regions. Attention is called to the necessity of biomonitoring in 4 regions of the reservoir, using benthic macroinvertebrates and physical and chemical sediment analyses and the adoption of a new way of managing this system

Os recursos hídricos são de grande importância para a vida, já que fazem parte dos processos metabólicos dos seres vivos. No decorrer dos anos, o aumento da atividade humana e seus consequentes impactos tem acarretado maior preocupação com a conservação destes recursos. Para que haja consumo de água pelos seres humanos, há a necessidade do tratamento da mesma, retirando-se as impurezas, deixando-a potável. Assim, os efluentes provenientes das atividades humanas, especialmente dos esgotos domésticos, devem ser tratados com precaução antes de serem lançados no corpo receptor diminuindo, de tal modo, a possibilidade de impactos ambientais. Nos ecossistemas aquáticos, os macroinvertebrados aquáticos têm sido utilizados nos últimos anos como ferramenta para avaliações da qualidade ambiental. Sabendo-se da problemática ocasionada pelo despejo de efluentes domésticos em rios e córregos, este trabalho apresenta como objetivo estudar a comunidade de macroinvertebrados do Ribeirão das Cruzes nas áreas à montante e à jusante do recebimento dos efluentes do sistema de tratamento de esgoto do Município de Araraquara. Os macroinvertebrados foram coletados em duas épocas do ano em quatro pontos distintos, utilizando-se rede em \"D\" pelo método de varredura. Juntamente à coleta, foram tomadas medidas in loco do teor de oxigênio dissolvido, pH, condutividade elétrica, temperatura da água, sedimento para determinação do teor de matéria orgânica e água para análise de fósforo e nitrogênio total. Os organismos foram identificados até o nível de família exceto Chironomidae identificados até gêneros ou espécie para posterior aplicação de índices bióticos e comunitários. Os resultados apontam que houve alteração na estrutura comunitária e diminuição na riqueza de macroinvertebrados aquáticos, após a ETE (estação de tratamento de esgoto) de Araraquara. A presença exclusiva do gênero Chironomus no ponto após a ETE aponta para um elevado impacto ambiental. / The hydric resources are essential to life, since they are part of the metabolic processes in living organisms. Along the years, as human activity has increased and its consequent impacts have caused a high concern in order to preserve such resources. In order to have water consumption by humans, it needs to be treated, making it potable. Thus, effluents that originate in human activities - especially domestic sewage - must be treated before being released to the receiving water body, reducing the possibility of environmental impact. In aquatic ecosystems, macroinvertebrates are being used along the last years as a tool to evaluate environmental quality. Once known the problem caused by the release of domestic effluents in rivers and streams, the present project aims to study the macroinvertebrates community within the Cruzes stream, upstream and downstream the area of wastewater treatment effluents from Araraquara municipality. The macroinvertebrates were collected in two seasons of the year at four different points, using network \"D\" by kick sampling method. Along the collection, steps were taken in place of the dissolved oxygen content, pH, electrical conductivity, water temperature, sediment to determine the content of organic matter and water for phosphorus and total nitrogen analysis. The organisms were identified at family level except Chironomidae identified to genera or species for subsequent application of biotic and community levels. The results show that there were changes in the community structure and a decrease in the richness of aquatic macroinvertebrates after the ETE (Treatment Sewage Station) in Araraquara. The exclusive presence Chironomus genre at the point after ETE points to a high environmental impact.

Made available in DSpace on 2015-03-05T16:19:36Z (GMT). No. of bitstreams: 0 Previous issue date: 26 / Programa Santander Universidades / Os ecossistemas lóticos apresentam um gradiente de variáveis ecológicas que se modificam da nascente até a foz, influenciando diretamente a sucessão da biota aquática. Em regiões temperadas os rios diferem-se daqueles localizados em regiões tropicais. Nas regiões tropicais o pulso de inundação exerce uma forte influência nas comunidades de macroinvertebrados. A distribuição e composição da comunidade de macroinvertebrados respondem às variações de fatores bióticos e abióticos e ainda, estão relacionadas com as diferentes regiões e tipos de hábitats disponíveis nos sistemas. Estudos relacionados à diversidade, estrutura e dinâmica de macroinvertebrados fornecem informações fundamentais para o conhecimento, acerca da biodiversidade e para programas de manejo e monitoramento dos recursos hídricos. Neste sentido o objetivo geral desta dissertação de mestrado foi conhecer a riqueza, a abundância, a composição e os grupos tróficos de macroinvertebrados, em nove arroios de pequena ordem em uma bacia hidrográfica do / Lotic ecosystems have a range of ecological variables that change from source to mouth, having direct influence on succession of aquatic biota. In temperate regions rivers are different from those located in tropical regions. In tropical regions the flood pulse has a strong influence on communities of macroinvertebrates. Distribution and composition of the community of macroinvertebrates respond to variations in biotic and abiotic factors and are related to different regions and types of habitat available in the systems. Studies on diversity, structure and dynamics of macroinvertebrates provide essential information on the biodiversity and for programs of management and monitoring of water resources. In this sense, the general objective of this master’s dissertation was to investigate the richness, abundance, composition and trophic groups of macroinvertebrates in nine small-sized streams in a hydrographic basin in southern Brazil and to analyze the influence of physical and chemical parameters of water and d

Com o intuito de conhecer o histórico da comunidade bentônica no reservatório do Guarapiranga para futuro estudo sobre a influência das diferentes formas de poluição na represa sobre o zoobentos, este trabalho foi desenvolvido a fim de coletar dados históricos da fauna de fundo e se houve variação na estrutura da comunidade ou não. Foram analisados quatro trabalhos realizados no período de inverno em quatro regiões médio-profundal do reservatório (Guarapiranga, Embu-Mirim, Embu-Guaçu e Parelheiros) ao longo dos anos, 1939, 1976, 1996 e 2010. A riqueza de dados presentada nos trabalhos refletiu a evolução do conhecimento em estudos limnológicos no Brasil e no mundo. A densidade de Oligochaeta apresentou aumento ao longo dos anos, assim como a de Chaoboridae. Por outro lado, Chironomidae que apresentava 30% em 1974 é pouco representativo em 2010. O ambiente mostrou forte e crescente enriquecimento orgânico em todos os pontos ao longo dos anos e isso colaborou para uma maior diversidade de grupos detritívoros (Tubificinae e Naidinae - Oligochaeta), por exemplo. Os níveis de oxigênio dissolvido no fundo diminuíram ao longo dos anos em todos as regiões. Chama-se a atenção para a necessidade de biomonitoramento nas 4 regiões da represa, utilizando inclusive os macroinvertebrados bentônicos e análises físicas e químicas do sedimento e a adoção de uma nova forma de gerenciamento deste manancial / With the purpose to know the history of the benthic community in Guarapiranga reservoir for future study about the influence of different sources of pollution in the reservoir over zoobenthos, this study was conducted to collect historical data of benthic fauna and variation in community structure. Four studies conducted during winter in four regions of the reservoir medium-profundal (Guarapiranga, Embu-Mirim, Embu-Guaçu and Parelheiros) over the years, 1939, 1976, 1996 and 2010 were analysed. The best richness of data presented in the works reflected the evolution of knowledge in limnological studies, in Brazil and worldwide. The density of Oligochaeta had an increase over the years as well as the Chaoboridae. On the other hand, Chironomidae presented 30% in the 70\' community and was not representative anymore in 2010. The environment showed strong organic enrichment for all regions along the years, and this has contributed to a greater diversity of detritivorous groups (Tubificinae and Naidinae - Oligochaeta), for example. The dissolved oxygen levels at the bottom declined over the years in all regions. Attention is called to the necessity of biomonitoring in 4 regions of the reservoir, using benthic macroinvertebrates and physical and chemical sediment analyses and the adoption of a new way of managing this system

This study was undertaken to determine the effects of rotenone applied during a fish control operation in September 1962 and the installation of Flaming Gorge Dam in November 1962 upon the distribution of invertebrates in the Green River. Since these two events, the river has changed from a warm, turbid stream to a cold, clear trout stream for about 45 miles below the dam. Totals of 234 bottom samples and 394 drift samples were collected between the dam and Ouray, Utah (166 miles below the dam). The species composition of the fauna above Carr Ranch was much simpler during 1964-65 than the reported pre-impoundment composition. Below Carr Ranch the species composition of the invertebrate fauna has changed little. Bottomfauna densities were highest near the dam (max. 6347/ft. 2) and decreased with increasing distance below the dam. Population densities below Carr Ranch (42.7 miles below the dam) appeared to be similar to reported pre-impoundment densities. Drift rates of Baetis nymphs and Simuliidae larvae were highest near the dam. Illumination, population density. of other organisms, and water temperature had significant effects on drift-net catches of Baetis and Simuliidae. Turbidity and water - level fluctuations had important effects under certain circumstances, while date, dissolved oxygen, and depth of water had little effect on drift - net catches.

Thredbo Village is a year round alpine resort located in Kosciusko National Park, south eastern New South Wales. Treated sewage effluent from Thredbo Village is discharged to the upper Thredbo River. The river is a rocky bottomed, high mountain stream (> 1,200 m altitude in the study area) flowing predominantly through subalpine woodland, the only major impact on the river within the study area was that of the Thredbo Village alpine ski resort. Nutrient concentrations were measured in the upper Thredbo River monthly from January to September 1983 at 9 sites along the river, both upstream and downstream of the effluent discharge. In addition, invertebrates were collected at the same sites in January, April and July 1983. The near pristine section of the upper Thredbo River upstream of Thredbo Village was low in phosphorus and nitrogen (<20 mg m-3 and <100 mg m-3 respectively). The sewage effluent discharge was high in phosphorus and nitrogen (up to 5,000 mg m-3 and 28,000 mg m-3 respectively). Phosphorus generally returned to concentrations similar to those measured in the pristine sections by 3.5 kilometres downstream of the discharge. Nitrogen (mostly in the form of nitrate and nitrite) often remained elevated down to the most downstream site, 8 kilometres downstream of the effluent discharge. The elevated nutrient concentrations immediately downstream of the effluent discharge stimulated the growth of attached filamentous algae in January when conditions for growth were most favourable. It is concluded that this growth provided an additional food source for several invertebrate taxa, Cricolopus sp. 12E and 160E (Diptera, Chironomidae), Conoesucidae sp. TR6, Oxyethira columba (Trichoptera), Nais sp., Aeolosomatus niveum (Oligochaeta), and Austrocercella tillyardi (Plecoptera), which occurred in higher numbers downstream of the effluent discharge. Downstream of the effluent discharge the taxonomic composition of the invertebrate community was not altered substantially from that upstream, although there was a significant increase in the abundance of the taxa which could take advantage of the increased food resource. The changes in the invertebrate community were not evident 3.5 kilometres downstream of the effluent discharge, which corresponded to the return of phosphorus concentrations to background levels. There were increased abundances of several invertebrate taxa downstream of both Thredbo Village and the rubbish tip in January which were consistent with, but not as great as, those downstream of the sewage effluent discharge. This was likely to be a result of increased nutrient loads from urban runoff and tip leachate at these sites which possibly lead to increased algal productivity. However, nutrient concentrations at these sites were not notably higher than at the control site. The sewage effluent discharge resulted in only small changes to the invertebrate community in April or July 1983.

Nature-like fishways are often constructed to restore connectivity in streams exploited for hydropower. They also have the potential to compensate for important habitats that have been degraded or lost. The aim of this thesis was to improve knowledge of the concept of nature-like fishway design, with special focus on their habitat compensation potential. This was done by comparing a nature-like fishway with four different habitat types, termed the biocanal, to six nearby natural reference creeks. In paper I the macroinvertebrate colonization of the biocanal was studied and the community composition was compared to that of the natural reference creeks. Furthermore, the potential for the biocanal to contain a diverse macroinvertebrate fauna was investigated. The results showed that the species composition of the benthic fauna in the biocanal was approaching that of the reference creeks and that the different habitat types in the biocanal contributed to the increased family diversity. In paper II the functional organization of the biocanal was studied using the functional feeding group approach. The results showed that after two years, the functional organization in the biocanal resembles that of the natural reference creeks.

Loss of wetland habitats across the nation is staggering and continues, especially in urbanizing areas. Thus, wetland restoration has become a priority. However, questions remain regarding system function and biotic communities. We studied a constructed floodplain wetland complex near Dallas, Texas. We sought to improve understanding of wetland ecosystem development under the influence of different approaches to wetland restoration in an urbanizing landscape. In the wetland complex, 10 constructed sloughs, approximately 70m by 15m, were designated for this study. Our experiment monitored the establishment of aquatic plant and invertebrate communities under different experimental conditions. In 5 sloughs, 5 native perennial hydrophyte species were transplanted in blocks in each slough, with the remaining 5 sloughs unplanted. Portions of each slough were caged to determine the effects of protective caging. Using 1m2 caged and neighboring uncaged areas as quadrats, we sampled vegetation and the invertebrate community over two years to determine the effects of restoration treatmentsSlough planting did not result in statistically different levels of plant cover. However, invertebrate abundance was greater in planted sloughs, and plant composition was different, comprised more of perennial species in planted sloughs than in unplanted sloughs. Caging did not have an effect on plant or invertebrate communities. However, changes due to time resulted in significant increases in plant cover and invertebrate abundance and shifts in community composition. Four of 5 transplanted species were emergent growth forms. Emergent cover and the remaining species, Potamogeton nodosus, a floating-leafed plant, accounted for invertebrate community variation. Transplanted emergent species did not fare well, though other emergent species did colonize the site, along with widespread coverage by submerged Najas guadalupensis. Potamogeton spread rapidly, colonizing unplanted sloughs, and this will likely affect community development across the site. Plant and invertebrate richness values were low, likely due to hydrological extremes and the short period of time since construction. Water level fluctuations resulted in plant communities dominated by obligate wetland plants, though drought stress took a toll on survival of plants and invertebrates in late summer. Community development and system function were dependent mostly upon time and hydrology. on the communities.