No description available.

Headwater drainage features (HDFs) in the GTA are commonly subjected to land-use modifications including agricultural uses and urbanization. A temporal study design approach was used to test whether the runoff being exported from previously modified HDFs differed from runoff exported from less disturbed forested channels. Drift nets were deployed in the permanent reaches of streams and in the HDF channels, to give an indication of the quality and quantity of drifting materials. Gastric lavage was used to remove stomach contents from creek chub living downstream from HDFs and these contents were used to determine if invertebrates in HDF runoff could act as food immediately upon reaching fish-bearing sections of stream. Reaches of streams associated with forested HDFs were found to have more fish than either those associated with agricultural or urban HDFs (203, 184 and 145 fish per forested, agricultural and urban site, respectively). Sites associated with forested catchments also had a greater number of salmonids per site. Conditions of high flow in the stream and the HDF coincided with an increased quantity of drifting invertebrates in all site types and land uses, as well as a decrease in the proportion of creek chub with empty stomachs. Overall, aquatic Diptera were the most numerous invertebrates captured in drift nets and in the stomach contents of creek chub. Hymenoptera, terrestrial Oligochaeta and Diplopoda also made major contributions to the diets of creek chub. Results indicate that HDFs in all land uses are exporting both aquatic and terrestrial invertebrates to main streams at times of high flow. Creek chub consume more prey at times of high flow, and this often includes terrestrial invertebrates, which must have been imported from terrestrial sources to the aquatic environment, however the degree to which they are exported by HDFs is still not clear. The series of complex interactions occurring at the HDF/main stream interface requires further study.

No description available.

nÃo hà / A preocupaÃÃo com processos que causam degradaÃÃo da qualidade dos recursos hÃdricos e dos ecossistemas aquÃticos tem se acentuado, principalmente, devido a enorme quantidade de poluentes e novas substÃncias que adentram nesse meio. Objetivou-se, com este trabalho, ampliar o conhecimento sobre a comunidade de macroinvertebrados aquÃticos do reservatÃrio GaviÃo em Itaitinga (CE), onde ocorre a captaÃÃo das Ãguas para o sistema de abastecimento de Ãgua da regiÃo metropolitana de Fortaleza e avaliar como os organismos respondem à disposiÃÃo dos resÃduos da ETA GaviÃo, utilizando o Ãndice BMWPâ. As coletas foram realizadas mensalmente, empregando um coletor do tipo Surber (500 Âm de abertura de malha) no perÃodo de outubro 2012 a maio de 2013. Foi coletado um total de 1.621 espÃcimes, distribuÃdos em 23 taxa. Mollusca foi o grupo dominante e frequente e Insecta apresentou maior riqueza. Segundo o Ãndice BMWPâ, verificou-se que o reservatÃrio GaviÃo encontra-se com suas Ãguas em qualidade duvidosa. / Concerns with the processes that cause water resources and ecosystem degradation are on the rise, especially because of large amounts of pollutants and substances that enter this medium. This study aimed to evaluate water macroinvertebrate communities in tanks used for water collection for urban use and to assess how organisms respond to waste generated in the water treatment plant. We collected a total of 1,621 specimens, distributed into 23 taxa. Mollusca was the dominant and frequent group and insecta was the most abundant. Based on feeding mode, there are more predatory organisms in relation to scrapers. We found no eudominant families. By using the BMWPâ score we verified that water quality in the âGaviÃoâ reservoir is questionable.

Rotenone is considered essential in the restoration of native fish populations; however, the technique is contentious and criticized, specifically concerning impacts to invertebrates. Knowledge of effects to non-target organisms is important for the management and conservation of fish populations. This thesis has two general objectives: (1) demonstrate the influence CFT Legumine™ rotenone has on benthic macroinvertebrates for restoration projects in Montana and New Mexico and (2) evaluate the immediate response by means of invertebrate drift. Chapters 2 and 4 incorporate results from four different restoration projects that examine benthic macroinvertebrate response. Results indicate treatment effects are minimal for Specimen and Cherry Creek projects in Montana. New Mexico projects, Comanche and Costilla Creek suggest a greater influence. Potassium permanganate used to neutralize rotenone, influenced communities in three of the four projects. Regardless, invertebrates in all four projects recovered one-year after treatment. Chapter 3 examines macroinvertebrate drift during rotenone treatment. Results suggest a delayed response compared to previous literature. Rotenone appears to have the greatest immediate influence on the early life stages of Ephemeroptera and Plecoptera. To reduce impacts of rotenone to invertebrates, managers should apply CFT Legumine and use the minimal dosage and duration to complete the projects goal of removing non-indigenous fish species.

The physical, chemical and biological characteristics of five southern English chalk streams in neighbouring catchments were investigated seasonally over two years. At the catchment scale, the five chalk rivers had very similar physio-chemical properties. Differences between years and between seasons were much greater than those between rivers or within-river longitudinal differences. Elevated inorganic nutrient concentrations, relative to reportedly 'pristine' systems, indicated some degree of catchment water quality deterioration in all five rivers. The effect of physical habitat degradation (channel overwidening and sedimentation) on river biota was investigated at a within-river, reach scale. The increased proportion of fine sediment within the coarse gravel substratum had a marked effect on invertebrate communities. Overwidening, however, was found to have little impact over the two years. Communities showed a high degree of stability between years, and between individual catchments, reflecting the high overall biological stability of these aquifer-fed river systems. Habitat manipulation experiments at the within-reach scale demonstrated the importance of substratum characteristics to macroinvertebrate communities. Invertebrate colonisation of newly exposed substrata over time was quantitatively and qualitatively different for coarse and fine particles - a function of shifting resource utilisation and microhabitat preferences. The relatively long time taken to fully colonise new substrata demonstrated the weak ability of chalk stream invertebrate communities to respond rapidly to changes in habitat, reflecting the stable physical nature of natural chalk streams and the vulnerability of their communities to anthropogenic disturbance.

Woody vegetation encroachment has become a major threat to tallgrass prairie streams mainly because of fire suppression. This process converts prairie streams from open to closed canopy systems. The effects of these riparian changes are poorly understood, but the relative importance of basal resources presumably shifts from primarily autochthonous to allochthonous with increasing canopy cover, potentially altering macroinvertebrate functional structure and production. To assess the effects of woody vegetation encroachment on stream ecosystem structure and function, riparian trees were removed from two headwater stream reaches on the Konza Prairie Biological Station (KPBS) in eastern Kansas. Experimental stream reaches were compared to streams with naturally open and closed canopies before and after the manipulation. Benthic organic matter and macroinvertebrates were collected monthly from each reach for one year before and one year after woody vegetation removal. Total community production in canopy removal reaches ranged from 8.9-10.2 g AFDM m-2 y-1 before riparian removal, and this increased significantly to 13.4-14.5 g AFDM m-2 y-1 after riparian removal. Scraper production in canopy removal reaches was 2.8-3.9 g AFDM m-2 y-1 before riparian removal, and increased significantly to 6.0-8.7 g AFDM m-2 y-1 after riparian removal, presumably due to enhanced food availability. Total community production in naturally open reaches ranged from 7.6-12.6 g AFDM m-2 y-1 before riparian removal and decreased to 6.5-9.8 g AFDM m-2 y-1 after riparian removal. Riparian forest removal altered macroinvertebrate production and functional structure, but higher macroinvertebrate production in canopy removal reaches compared to naturally open reaches suggested natural conditions were not restored one year after riparian removal. However, macroinvertebrate communities in naturally open and canopy removal reaches became more similar after riparian removal. Functional structure, based on production, in naturally open and canopy removal reaches after riparian removal was dominated by scrapers (45-60% of total production), with similar proportions of collector-gatherers (12-26%) and predators (15-25%). Collector-filterers and shredders contributed < 9% of total production in naturally open and canopy removal reaches after riparian removal. Results demonstrate that woody vegetation encroachment and riparian forest removal significantly influence tallgrass prairie stream structure and function. Information from this study can help inform and guide management, restoration, and conservation of remaining tallgrass prairie streams.

The southern Appalachian forests of the United States are undergoing changes due to the death of hemlock trees attacked by the hemlock wooly adelgid. This paper addresses the management impacts of Rhododendron maximum removal in the riparian and upslope areas previously occupied by hemlock. This study measured the consequences macroinvertebrates faced due to riparian Rhododendron removal from 300 m reaches of two low order streams. Two additional low order streams served as reference sites for the experiment. The stream macroinvertebrate communities were assessed using a before-after controlled impact model comparing communities between fall 2014 to those from fall 2015 and from spring 2015 to spring 2016. Macroinvertebrate collections consisted of 288 samples with a total of 61,056 individuals. There was a significant increase in collector-gathers in both removal sites, mostly from increases in Ephemerellidae and Chironomidae. There was also a significant decrease in filter feeding organisms in the removal reaches. Traits analysis also revealed that several traits that are shared by collector gathers also increased, e.g., short life cycles that are related to the increase in Chironomidae. Using Nonmetric Multidimensional Scaling (NMDS) and permutational MANOVA significant annual differences in macroinvertebrates were found in all of the stream reaches during both seasons. However, the trait based NMDS and permutational MANOVA found significant change only in one removal site between fall collections based on traits. These finding are consistent with findings from logging and other riparian removal projects; suggesting that the short-term impacts of selective Rhododendron removal on benthic macroinvertebrates are comparable to that of logging activity. / Master of Science

No description available.

This paper is about analyzing water quality of a stream that flows in southwest of Swedencalled Hasslebäcken. The stream is a tributary of Suseån and has its springs in the naturereserve Biskopstorp and flows through a mixed landscape of mostly spruce forests andagriculture land. Little is known about Hasslebäcken and its water and therefore a study by request of Suseåns vattenråd was performed. The study consisted of analyzing the water ofphosphorous, nitrogen, pH, suspended particles and conductivity. To broaden the examination of water quality sampling of benthic macroinvertebrates and two index (ASPTindex and Shannon’s diversity index) of water quality were used. Another part of the study were to search for fish barrier in the stream and to evaluate the possibilities for troutspawning and habitats. The whole stretch of the stream were examined and eleven differentsampling sites were used. The results show that Hasslebäckens upper parts have low levelsof nutrients while the lower parts show intermediate to extremely high levels. The indexresults points at low ecological values for Shannon and high ecological values for ASPT. Thisis normal for a stream that flows through an agricultural landscape. The results concerning pH show a lower pH in the upper parts than in the lower parts. This is also normal for a stream in a production forest of spruce in these parts of Sweden. Hasslebäcken also have several fish barrier that prevent various fish species to migrate up along the stream from thesea. The evaluation of trout habitats and spawning area show decent possibilities for successful reproduction and growth.