Academic literature on the topic 'Lotic ecosystem – Quality'

Flow and water quality of rivers are highly dynamic. Water quantity and quality are subjected to simultaneous physical, chemical and biological processes making it difficult to accurately assess lotic ecosystems. Our study investigated net ecosystem production (NEP) relying on high-frequency data of hydrology, hydrodynamics and water quality. The Kanawha River, West Virginia was investigated along 52.8 km to estimate NEP. Water quality data were collected along the river using three distributed multiprobe sondes that measured water temperature, dissolved oxygen, dissolved oxygen saturation, specific conductance, turbidity and ORP hourly for 71 days. Flows along the river were predicted by means of the hydrologic and hydrodynamic models in Hydrologic Simulation Program in Fortran (HSPF). It was found that urban local inflows were correlated with NEP. However, under hypoxic conditions, local inflows were correlated with specific conductance. Thus, our approach represents an effort for the systematic integration of data derived from models and field measurements with the aim of providing an improved assessment of lotic ecosystems.

Water Quality Index (WQI) as a tool to assess the water quality status provides advice related to the use of water quality monitoring data and it is a way for combining the complex water quality data into a single value or single statement.The present study was conducted on Al- Hilla river in the middle of Iraq from August 2012 to July 2013 at five selected stations in the river, from Al- Musaib city to Al- Hashimya at the south of Hilla to determine its suitability for aquatic environment (GWQI), drinking water (PWSI) and irrigation (IWQI).This index offers a useful representation of the overall quality of water for public or any intended use as well as indicating pollution, water quality management, and decision making. According to the obtained results, it can be concluded that the EC, TSS, Total hardness, Ca, Mg, DO, BOD5, and NO3 moved away from the desired standards when the temperature rises. The variable of value of this index may be due to increasing the ration of organic matters and converting the carbonate to bicarbonate. The results recorded high value of calcium and magnesium more than the standard value of WHO and IQS (50 mg/l and high value of total hardness more than 500 mg/l). Irrigation water quality index (IWQI) in the study sites were ranged between 66-83 ranged between fair and good.

ABSTRACT The ecosystems offer to the socio-economic system a series of goods and services derived from their processes and biodiversity. Ecosystem services offered by a river are at their highest potential when the river status is close to the natural one. Once the river is affected by human impact due to resources exploitation, hydro technical works, water abstraction or improper land use, the ecological status declines and the ecosystem services become scarce. This is why an ecological assessment is necessary in order to establish the connection between the ecosystem services and the human impact. In this paper, the ecological assessment of Timiș River was done, allowing the classification of the river in four sectors with different ecological statuses, associated with the various human impacts that differently affect the quality of the water, the riverbed and the flooding area.

The Meriç River, the longest river of the Balkans, is the most important aquatic ecosystem within the Thrace Region of Turkey, along with its main tributaries, the Tunca and Ergene Rivers. In this study, the sediment quality of Meriç, Tunca, and Ergene Rivers was evaluated by using the Potential Ecological Risk Index (RI) and the Biological Risk Index (mERM-Q), both widely used methods in sediment quality assessment studies, to assess the ecological and biological risks of heavy metals within the river ecosystems. According to the results of the Biological Risk Index, nickel and chromium displayed the highest risk factors, and in terms of the Potential Ecological Risk Index, cadmium yielded the highest risk factor across all the investigated lotic ecosystems.

River regulation impacts lotic ecosystem processes; however, the effect of a gradient of regulation on these attributes has rarely been studied. This study examined the effects of a river regulation gradient on longitudinal trends in water quality and benthic algal and macroinvertebrate assemblages in three tributaries of the Hunter River, New South Wales, Australia. Longitudinal patterns were expected to differ across rivers, with recovery being proportional to its regulation gradient. Significant differences in longitudinal trends were tested using permutational multivariate analysis of variance (PERMANOVA) through exploration of the river by distance from source interaction. Multi-dimensional scaling (MDS) ordination plots identified sites responsible for any significant interaction observed. Similarity percentage analysis (SIMPER) analyses identified variables/taxa responsible for differences at sites below dams. BEST analyses identified environmental variables best explaining biological assemblage patterns. Significant differences in longitudinal trends were observed for all attributes. Increases in the regulation gradient most affected macroinvertebrate assemblages, followed by water quality and benthic algal assemblages respectively. Downstream recovery was absent in the heavily regulated river at its most downstream site, whereas recovery was observed on corresponding sites of the moderately regulated river. The study suggests that a gradient in river regulation increases the magnitude of disruption of lotic ecosystems, with recovery dependent on this gradient.

Karr's Index of Biotic Integrity (IBI) approach provides a biological measure of ecosystem health using a wide spectrum of metrics which can be extracted from fish catch data obtained using standardized methods. Extensive electrofishing surveys of littoral fish assemblages, conducted in three Great Lakes' Areas of Concern, provided the basis for developing a lacustrine IBI that was 12 metrics of three broad types: (i) species composition, (ii) trophic composition, and (iii) abundance and condition. In contrast with lotic IBIs where diversity and abundance metrics have mostly been used, several biomass metrics were adopted to accommodate the large size range of lentic fishes. The variability of repeated measures was low enough to allow valid testing of intertransect differences with three to five samples per transect. Comparisons among survey areas showed significant differences consistent with the varying levels of ecosystem degradation. Analyses of mean IBI values with measures of submerged vegetation density and cover by transect produced significant positive correlations. This IBI developed for the Great Lakes' littoral zone, both by design and by demonstrated correlations, integrates the effects of four main factors influencing fish assemblages and hence revealing ecosystem health: exotic fishes, water quality, physical habitat supply, and piscivore abundance.

Epipsammic diatoms have important implications for ecosystem processes in lotic environments. Most of the studies on benthic diatoms concentrate on epilithic diatoms and very little is known about epipsammic diatoms. The objective of this study was to assess epipsammic diatom communities in streams in relation to environmental conditions. Epipsammic diatoms and water quality sampling was done at 7 sites during summer base flow period (2008). Forward stepwise multiple regression and canonical correspondence analysis (CCA) were used to determine environmental gradients along which species vary with physical and chemical variables. A total of 112 diatom species distributed among 44 genera were recorded. Altitude and the process of eutrophication played a significant role in structuring diatom communities in the study region.

Clear-cut logging rapidly affects stream macroinvertebrates through substantial alteration of terrestrial–aquatic resource linkages; however, lesser known are the long-term influences of forest succession on benthic macroinvertebrate assemblages, which play key roles in stream ecosystem function. We compared secondary production and standing crops of detritus in two mountain headwater streams within Coweeta Hydrologic Laboratory, North Carolina, USA, as part of a long-term, paired-watershed investigation of macroinvertebrate recovery from whole-catchment logging. Mean annual habitat-weighted abundance and biomass in the disturbed stream (catchment entirely logged 26 years prior) did not differ from that of the reference stream, and secondary production was only 0.8 g ash-free dry mass (AFDM)·m–2·year–1 greater in the disturbed stream (disturbed, 10.1; reference, 9.3). Taxonomic composition, shredder–scraper ratios, and North Carolina biotic index scores were more similar between streams than in previous years. However, mean annual standing crops of benthic organic matter (BOM) were much lower in the disturbed stream (167 g AFDM·m–2) than in the reference stream (339 g AFDM·m–2), and the disturbed stream supported greater macroinvertebrate biomass per unit BOM. We suggest that despite similarities in macroinvertebrate structure and function, past logging activity continues to influence consumer–resource relationships in the disturbed stream through enhanced resource quality.

Tributary confluences are sites along a main channel where, because of the introduction of water and (or) sediment, the water volume, bed sediment character, and water quality of the mainstream can change abruptly. These shifts ensure that abiotic gradients seldom vary smoothly or continuously for distances of more than 100–102 km along any river system. The ways in which tributaries and related sediment recruitment points structure longitudinal changes in physical habitat are examined. Variables of importance to stream biota are affected and, in turn, it is suggested that the arrangement of tributaries and related features is an important control on the longitudinal organisation of macroinvertebrate benthos at moderate spatial scales. A new model is presented that stresses the importance of hydrological and sedimentological networks for organising lotic fauna. The link discontinuity concept emphasises the discontinuous nature of lotic ecosystem gradients, addresses the importance of tributaries in unregulated as well as regulated rivers, and extends, to its logical conclusion, the limited recognition of tributary influence in the river continuum concept. A case study from British Columbia, Canada, illustrates the general merit of the new model.

Nas últimas décadas, tem-se observado uma expressiva queda da qualidade ambiental e perda de biodiversidade nos ecossistemas aquáticos em função de múltiplos impactos advindos de atividades antrópicas. Dessa forma, considerando-se que a estrutura das comunidades pode ser alterada por tais perturbações, diversos métodos têm sido propostos para avaliações da qualidade nesses ecossistemas, destacando-se, entre eles, o uso dos macroinvertebrados bentônicos. Alguns estudos empregando estes indicadores defendem a sua identificação ao nível genérico por fornecer maior número de informações, resultar em classificações ambientais mais confiáveis e apresentar melhor capacidade de distinção entre os pontos, quando comparado aos níveis de resolução mais abrangentes. Entretanto, na maioria dos trabalhos a identificação desse grupo restringe-se ao nível de família, principalmente em função da economia nos recursos despendidos durante a identificação o que não se justifica caso este nível não retenha informações suficientes para que os objetivos sejam alcançados. Neste trabalho, esse conflito foi avaliado através da comparação de avaliações biológicas decorrentes da aplicação de índices estruturais baseados na identificação de Chironomidae, ao nível genérico com o de sub-família/tribo. Foram utilizadas amostras de organismos bentônicos, bem como os dados físicos, químicos e microbiológicos coletados em sete pontos de amostragem que fizeram parte de vários projetos da CETESB (Companhia de Tecnologia de Saneamento Ambiental), conduzidos ao longo de diferentes anos e classificados, de acordo com o ICBRIO (Índice da Comunidade Bentônica para rios) em ambientes de qualidade péssima, ruim, regular, boa e ótima. As coletas foram padronizadas em relação ao período (inverno) e ao tipo de hábitat amostrado (margem deposicional). As amostras foram obtidas em triplicata com o auxílio de pegadores (Ponar e Petersen modificado) e o material selecionado em rede com abertura de malha 0,5 mm. A contagem e identificação dos organismos foram feitas com o auxílio de estereomicroscópio, microscópio óptico e bibliografia especializada. Para definir o gradiente de qualidade, as variáveis ambientais foram submetidas a uma Análise de Agrupamento pelo método de Ward, empregando-se a Distância Euclidiana Simples. Já os valores de densidade foram reunidos em uma matriz de distância de Bray-Curtis agrupada pelo método de média de grupo não ponderada a fim de verificar o grau de similaridade entre os pontos e se o nível de identificação taxonômica interfere nas associações formadas. Com o intuito de verificar a sensibilidade do nível taxonômico do dado ao gradiente de qualidade ambiental, bem como testar a possível influência do refinamento taxonômico na sensibilidade do ICBRIO foram empregadas as métricas Riqueza, Diversidade de Shannon-Wiener, Índice de Comparação Seqüencial, Dominância de Grupos Tolerantes e Riqueza de Táxons Sensíveis. Tendo por objetivo o diagnóstico das condições ambientais, com redução de custos e tempo de manipulação das amostras, mas com informações relevantes que subsidiem os tomadores de decisão, o presente trabalho vem descartar o emprego do nível de resolução genérico na identificação das larvas de Chironomidae. Os resultados expostos confirmaram a aplicabilidade do ICBRIO com a identificação deste grupo aos níveis de sub-família/tribo na avaliação da qualidade ambiental, demonstrando não serem necessárias eventuais alterações nos seus moldes.
In the last decades, it has been observed an expressive deterioration of the environmental quality and biodiversity loss in the aquatic ecosystems as function of anthropogenic activities. Considering that communities' structure can be altered by such disturbances, several methods have been proposed for quality assessment in those ecosystems, standing out, among them, the use of the benthic macroinvertebrates. Some studies using these indicators defend the generic level identification as they supply more information, result in more reliable environmental classifications and present better distinction capacity among sites, when compared to broader levels. However, in most of the works the identification of this group is limited to the family level, mainly due to resources saving during the identification, which is not justified in the case this level misses information to classification aims. In this work, comparison of current biological evaluations through Chironomidae identification structural indexes at the generic level with the one at sub-family/tribe was evaluated. Benthic organisms samples, as well as physical, chemical and microbiological data were collected in seven sampling sites, from several projects taken along different years by CETESB (Company of Technology of Environmental Sanitation), which classified the environment as, according to ICBRIO (Benthic Community Index for rivers), worst, bad, regular, good and excellent quality. The collections were standardized to winter period and to type of sample habitat (depositional river margin). Triplicates were obtained with modified Ponar and Petersen grabs on retained material by 0.5mm-mesh sieve. Counting and identification based on specialized literature were done with the stereomicroscope, and optical microscope. To define the quality gradient, the environmental variables were submitted to a Cluster Analysis by the Ward method, using the simple Euclidean Distance. Density values were lumped on a Bray-Curtis distance matrix by the Unweighted Pair Group method in order to verify the similarity degree among the points and the interferences of taxonomic identification level on the formed associations. Aiming to check the sensibility of the data taxonomic level to the environmental quality gradient, as well as to test the possible influence of taxonomic refinement in the ICBRIO's sensibility, several metrics (Richness, Shannon-Wiener Diversity Index, Sequential Comparison Index, Dominance of Tolerant Groups and Richness of Sensitive Taxa) were used. Seeking the diagnosis of the environmental conditions, reducing costs and manipulation time of the samples, but keeping relevant information to subsidize the policy managers, the present work discards the need of the generic resolution level in the Chironomidae larvae identification. The exposed results confirmed the applicability of ICBRIO with the identification of this group at sub-family/tribe levels on the environmental quality assessment, demonstrating no need of eventual modification in the method.

Mestrado de dupla diplomação com o Institute Agronomic and Veterinary Hassan II
Freshwater ecosystems are threatened by several pressures worldwide. Water pollution and eutrophication, the degradation and fragmentation of aquatic and riparian environments, overexploitation of resources, the dispersion of non-native species and more recently climate change have contributed to the loss of biodiversity and ecological integrity of rivers. For this reason, river conservation and management are essential to guarantee all associated ecosystem goods and services, this taking into account the biotic and biotic factors. Which leads to the objectives of the present study which were: 1) to evaluate the impact of abiotic factors on the biological quality of a watercourse, the river Fervença belonging to the drainage bassin of River Sabor (NE of Portugal), subject to anthropic pressures, and 2) to determine the influence of biotic factors, namely the complex relationship between fish and bivalves, in the ecological integrity of lotic systems. In the spring of 2020, abiotic (i.e. water quality and habitats) and biotic (i.e. macroinvertebrates and fish) characterization of 7 sampling sites were made, using the Water Framework Directive protocols. The results showed a marked decrease in the quality of water, habitats and biota in sampling sites located downstream of the city of Bragança, as a result of the input of contaminants from the urban environment, despite the presence of a wastewater treatment plant (WWTP). The degradation of abiotic conditions has led to the disappearance of species sensitive to pollution and to the loss of biodiversity, biotic relationships and ecological functions in the aquatic system. In this context, the relationship between a bivalve, the unionoid Anodonta anatina, and the fish fauna present in the river Sabor was studied. Four native Iberian species (Luciobarbus bocagei, Squalius alburnoides, Squalius carolitertii and Pseudochondrostoma duriense) and one non-native species (Alburnus alburnus) were tested in the laboratory. All fish species functioned as viable hosts for Anodonta anatina due to the wide distribution of this bivalve, although the higher rates of metamorphosis were found for a native species, Squalius carolitertii. For the conservation and management of NE Portugal's aquatic systems, measures for the rehabilitation of disturbed ecosystems and the conservation of priority habitats are essential, namely for threatened native species.
Os ecossistemas de água doce estão ameaçados por várias pressões à escala mundial. A poluição e eutroficação da água, a degradação e fragmentação de ambientes aquáticos e ribeirinhos, a sobreexploração de recursos, a dispersão de espécies não nativas e mais recentemente as alterações climáticas têm contribuído a perda de biodiversidade e integridade ecológica de rios. Por tal motivo, a conservação e gestão de rios é fundamental para garantir todos os bens e serviços ecossistémicos associados. O presente estudo teve como objetivos: 1) avaliar o impacto de fatores abióticos na qualidade biológica de um curso de água, o rio Fervença (NE de Portugal), sujeito a pressões antrópicas, e 2) determinar a influência de fatores bióticos, nomeadamente da relação complexa entre peixes e bivalves, na integridade ecológica dos sistemas lóticos. Na primavera de 2020 foi feita a caracterização abiótica (i.e. qualidade da água e habitats) e biótica (i.e. macroinvertebrados e peixes) de 7 locais de amostragem, com recurso aos protocolos da Diretiva Quadro da Água. Os resultados evidenciaram uma diminuição acentuada da qualidade da água, dos habitats e do biota nos locais situados a jusante da cidade de Bragança, como resultado do input de contaminantes do meio urbano, apesar da presença duma estação de tratamento de águas residuais (ETAR). A degradação das condições abióticas levou ao desaparecimento de espécies sensíveis à poluição e à perda de biodiversidade, relações bióticas e funções ecológicas no sistema aquático. Neste âmbito, foi estudada a relação entre um bivalve, o unionídeo Anodonta anatina, e a fauna piscícola presente no rio Sabor. Foram testadas, em laboratório, quatro espécies nativas da Ibéria (Luciobarbus bocagei, Squalius alburnoides, Squalius carolitertii e Pseudochondrostoma duriense) e uma espécie não nativa (Alburnus alburnus). Todas as espécies piscícolas funcionaram como hospedeiros viáveis de Anodonta anatina em virtude da distribuição alargada deste bivalve, embora as taxas superiores de metamorfose tivessem sido encontradas para uma espécie nativa, o Squalius carolitertii. Para a conservação e gestão dos sistemas aquáticos do NE Portugal são essenciais medidas de reabilitação de ecossistemas perturbados e a conservação de habitats prioritários, nomeadamente para as espécies nativas fortemente ameaçadas.

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

<em>Abstract.</em> —Freshwater tropical island environments support a variety of fishes that provide cultural, economic, and ecological services for humans but receive limited scientific, conservation, and public attention. Puerto Rico is a Caribbean tropical island that may serve as a model to illustrate the interactions between humans and natural resources in such complex ecosystems. The native freshwater fish assemblage of Puerto Rico is distinct from mainland assemblages in that the assemblage is not diverse, all species are diadromous, and they may be exploited at multiple life stages (e.g., postlarva, juvenile, adult). Primary large-scale drivers of recent water-use policy include economic growth, human population density, and urbanization, with climate change as an overarching influence. Watershed and riparian land use, water quality, river flow and instream physical habitat, river habitat connectivity, exotic species, and aquatic resource exploitation are important proximate factors affecting the ecosystem and fisheries. Research on ecological processes and components of the stream and river fish assemblages has expanded the knowledge base in the past decade with the goal of providing critical information for guiding the conservation and management of the lotic resource to optimize ecosystem function and services. The greatest challenge facing Caribbean island society is developing policies that balance the needs for human water use and associated activities with maintaining aquatic biodiversity, ecological integrity and services, and sustainable fisheries. Achieving this goal will require broad cooperation and sustained commitment among public officials, agency administrators, biologists, and the public toward effective resource management.

Chapter 1 provides an overview of the current economic context for the global trend for economic quality and growth called the quality of life (QoL). Industries or businesses are progressively impacted by this trend in terms of the provision of a variety of improved QoL or wellbeing through service ecosystems. In addition, this chapter provides a rationalization of the vision for collective wellbeing toward economic quality and growth. The rationale is unfolded in terms of the provision of a conceptual model of collective wellbeing grounded in the logic of value co-creation, empowerment, and self-determined behaviors. This chapter provides the grounding mindset for the imperative elements and rationales for service providers to better design the customers (or stakeholders) empowerment processes for the co-creation of QoL wellbeing values, realizing collective wellbeing for economic quality and growth.

<em>Abstract.</em>—Urban development modifies the production and delivery of runoff to streams and the resulting rate, volume, and timing of streamflow. Given that streamflow demonstrably influences the structure and composition of lotic communities, we have identified four hydrologic changes resulting from urban development that are potentially significant to stream ecosystems: increased frequency of high flows, redistribution of water from base flow to storm flow, increased daily variation in streamflow, and reduction in low flow. Previous investigations of streamflow patterns and biological assemblages provide a scale of ecological significance for each type of streamflow pattern. The scales establish the magnitude of changes in streamflow patterns that could be expected to produce biological responses in streams. Long-term streamflow records from eight streams in urbanizing areas of the United States and five additional reference streams, where land use has been relatively stable, were analyzed to assess if streamflow patterns were modified by urban development to an extent that a biological response could be expected and whether climate patterns could account for equivalent hydrologic variation in the reference streams. Changes in each type of streamflow pattern were evident in some but not all of the urban streams and were nearly absent in the reference streams. Given these results, hydrologic changes are likely significant to urban stream ecosystems, but the significance depends on the stream’s physiographic context and spatial and temporal patterns of urban development. In urban streams with substantially altered hydrology, short-term goals for urban stream rehabilitation may be limited because of the difficulty and expense of restoring hydrologic processes in an urban landscape. The ecological benefits of improving physical habitat and water quality may be tempered by persistent effects of altered streamflow. In the end, the hydrologic effects of urban development must be addressed for restoration of urban streams.

Information technology has enabled tertiary health care providers to improve patient access to preventive and post-discharge care transition services. When such services are supported by facilities that are under the control of the hospital, hospitals can still influence the delivery and overall quality of patient care services. However, for a variety of reasons, many hospitals rely on external care providers who operate relatively independently from the hospital to deliver these services. As such, service delivery intended to create efficiency and value to patients can become complex, challenging to deliver, and resource intensive—especially if the service delivery spans a prolonged time horizon. This chapter discusses one case of an intermediary who helps hospitals address the smoking cessation needs of patients. Using service dominant logic research, the service exchanges among three different ecosystems (healthcare providers, intermediary, and patients) are modeled and intelligence needed to align their goals using blockchain architecture is highlighted.