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Artykuły w czasopismach na temat "In-stream nutrient concentrations"
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Bernal, S., A. Lupon, M. Ribot, F. Sabater i E. Martí. "Riparian and in-stream controls on nutrient concentrations along a headwater forested stream". Biogeosciences Discussions 11, nr 7 (29.07.2014): 11597–634. http://dx.doi.org/10.5194/bgd-11-11597-2014.
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Abstract. Headwater streams have a strong capacity to transform and retain nutrients, and thus, a longitudinal decrease in stream nutrient concentrations would be expected from in-stream nutrient removal alone. Yet, a number of other factors within the catchment, including biogeochemical processing within the riparian zone and export to streams, can contribute to stream nutrient concentration, which may overcome the effect of in-stream biogeochemical processing. To explore this idea, we analyzed the longitudinal patterns of stream and riparian groundwater concentrations for chloride (Cl−), nitrate (NO3−), ammonium (NH4+), and phosphate (PO43−) along a 3.7 km reach at an annual scale. The reach showed a gradual increase in stream and riparian width, riparian tree basal area, and abundance of riparian N2-fixing tree species. Concentrations of Cl− indicated a~strong hydrological connection at the riparian-stream edge. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high biogeochemical processing at the riparian-stream edge and within the stream. A mass balance approach along the reach indicated that, on average, in-stream net nutrient uptake prevailed over release for NH4+ and PO43−, but not for NO3−. On an annual basis, in-stream processes contributed to change stream input fluxes by 11%, 26%, and 29% for NO3−, NH4+, and PO43−, respectively. Yet, longitudinal trends in concentration were not consistent with the prevailing in-stream biogeochem ical processes. During the riparian dormant period, stream concentration decreased along the reach for NO3−, but increased for NH4+ and PO43−. During the riparian vegetative period, NO3− and PO43− increased along the reach while NH4+ showed no clear pattern. These longitudinal trends were partially related to riparian forest features and groundwater inputs, especially for NO3− and PO43−. Our study suggests that even though in-stream biogeochemical processing was substantial, the riparian zone can modulate the longitudinal variation in stream nutrient chemistry in this headwater stream.
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Cortelezzi, Agustina, Carolina Ocón, María V. López van Oosterom, Rosana Cepeda i Alberto Rodrigues Capítulo. "Nutrient enrichment effect on macroinvertebrates in a lowland stream of Argentina". Iheringia. Série Zoologia 105, nr 2 (czerwiec 2015): 228–34. http://dx.doi.org/10.1590/1678-476620151052228234.
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ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized), upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.
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Bernal, S., A. Lupon, M. Ribot, F. Sabater i E. Martí. "Riparian and in-stream controls on nutrient concentrations and fluxes in a headwater forested stream". Biogeosciences 12, nr 6 (24.03.2015): 1941–54. http://dx.doi.org/10.5194/bg-12-1941-2015.
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Abstract. Headwater streams are recipients of water sources draining through terrestrial ecosystems. At the same time, stream biota can transform and retain nutrients dissolved in stream water. Yet studies considering simultaneously these two sources of variation in stream nutrient chemistry are rare. To fill this gap of knowledge, we analyzed stream water and riparian groundwater concentrations and fluxes as well as in-stream net uptake rates for nitrate (NO3−), ammonium (NH4+), and soluble reactive phosphorus (SRP) along a 3.7 km reach on an annual basis. Chloride concentrations (used as conservative tracer) indicated a strong hydrological connection at the riparian–stream interface. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high in-stream biogeochemical processing. In-stream net nutrient uptake (Fsw) was highly variable across contiguous segments and over time, but its temporal variation was not related to the vegetative period of the riparian forest. For NH4+, the occurrence of Fsw > 0 μg N m−1 s−1 (gross uptake > release) was high along the reach, while for NO3−, the occurrence of Fsw < 0 μg N m−1 s−1 (gross uptake < release) increased along the reach. Within segments and dates, Fsw, whether negative or positive, accounted for a median of 6, 18, and 20% of the inputs of NO3−, NH4+, and SRP, respectively. Whole-reach mass balance calculations indicated that in-stream net uptake reduced stream NH4+ flux up to 90%, while the stream acted mostly as a source of NO3− and SRP. During the dormant period, concentrations decreased along the reach for NO3−, but increased for NH4+ and SRP. During the vegetative period, NH4+ decreased, SRP increased, and NO3− showed a U-shaped pattern along the reach. These longitudinal trends resulted from the combination of hydrological mixing with terrestrial inputs and in-stream nutrient processing. Therefore, the assessment of these two sources of variation in stream water chemistry is crucial to understand the contribution of in-stream processes to stream nutrient dynamics at relevant ecological scales.
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Elsdon, Travis S., i Karin E. Limburg. "Nutrients and their duration of enrichment influence periphyton cover and biomass in rural and urban streams". Marine and Freshwater Research 59, nr 6 (2008): 467. http://dx.doi.org/10.1071/mf07085.
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Although it is well known that land use affects nutrient dynamics and algal growth in streams, the responses to different durations of nutrient supply are poorly understood. The associations of benthic (periphyton-dominated) biomass with concentrations of dissolved nitrogen and phosphorus in rural and urban streams in New York were quantified. Biomass was significantly greater (2-fold) in the urban compared with the rural stream, which was associated with differences in dissolved nutrients. Experimental field enrichment of nutrient concentrations and duration of exposure altered benthic periphyton. Increasing nutrients by 60–99% of ambient concentrations increased periphyton percentage cover and biomass. Periphyton abundance also increased with increasing duration of exposure to nutrients (2, 4 and 8 weeks); however, short-term pulses of nutrients (2 weeks) had no significant effect in the rural stream. These results indicate that effective management of nutrient delivery, by reducing time periods of high nutrient load, will minimise impacts to benthic environments.
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Dodds, Walter K., Val H. Smith i Kirk Lohman. "Nitrogen and phosphorus relationships to benthic algal biomass in temperate streams". Canadian Journal of Fisheries and Aquatic Sciences 59, nr 5 (1.05.2002): 865–74. http://dx.doi.org/10.1139/f02-063.
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Knowledge of factors limiting benthic algal (periphyton) biomass is central to understanding energy flow in stream ecosystems and stream eutrophication. We used several data sets to determine how water column nutrients and nonnutrient factors are linked to periphytic biomass and if the ecoregion concept is applicable to nutrientperiphyton relationships. Literature values for seasonal means of biomass of periphyton, nutrient concentrations, and other stream characteristics were collected for almost 300 sampling periods from temperate streams. Data for benthic chlorophyll and nutrient concentrations from a subset of 620 stations in the United States National Stream Water-Quality Monitoring Networks were also analyzed. The greatest portion of variance in models for the mean and maximum biomass of benthic stream algae (about 40%) was explained by concentrations of total N and P. Breakpoint regression and a two-dimensional KolmogorovSmirnov statistical technique established significant breakpoints of about 30 µg total P·L1 and 40 µg total N·L1, above which mean chlorophyll values were substantially higher. Ecoregion effects on nutrientchlorophyll relationships were weak. Ecoregion effects were cross-correlated with anthropogenic effects such as percent urban and cropland area in the watershed and population density. Thus, caution is necessary to separate anthropogenic effects from natural variation at the ecoregion level.
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Matej-Lukowicz, Karolina, Ewa Wojciechowska, Nicole Nawrot i Lidia Anita Dzierzbicka-Głowacka. "Seasonal contributions of nutrients from small urban and agricultural watersheds in northern Poland". PeerJ 8 (6.02.2020): e8381. http://dx.doi.org/10.7717/peerj.8381.
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Diffuse sources of pollution like agricultural or urban runoff are important factors in determining the quality of surface waters, although they are more difficult to monitor than point sources. The objective of our study was to verify assumptions that the inflow from agricultural nutrient sources is higher than from urbanized ones. It has been done by comparing the nutrients and organic matter concentrations and loads for three small streams in northern Poland (Pomerania Region). Two streams flowing through agricultural catchments and an urban stream flowing through the city of Gdansk were analysed. Concentrations of nutrients: N-NO${}_{3}^{-}$ N-NH${}_{4}^{+}$, P-PO${}_{4}^{3-}$, total phosphorus, total nitrogen and COD were measured 1–3 times per month in the period from July 2017 to December 2018 in agricultural watersheds and from October 2016 to March 2018 for an urban stream. Seasonal changes in concentrations were analysed with descriptive statistics tools. Principal Component Analysis (PCA) was used to point out the most significant factors determining variations in nutrients and organic matter concentrations with respect to different seasons. The factors included a number of characteristics regarding the catchment and streams: total catchment area, stream length, watershed form ratio, stream slope, flow rate and land use with respect to paved areas, agricultural areas and green areas (parks, forests, meadows and pastures). Although concentrations of nitrogen compounds were higher in streams flowing through agricultural areas, our study showed that total concentrations of phosphorus were higher in the urban stream, especially in summer. In agricultural areas the summer concentrations of nutrients were not high, which was probably due to dense vegetation. The correlation between P-PO${}_{4}^{3-}$ concentration and size of agricultural area in the catchment was observed in winter when no vegetation field cover exists. Our study shows an urgent need to monitor the nutrient loads carried with urban streams especially if discharged into receivers prone to eutrophication.
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Johnston, N. T., E. A. MacIsaac, P. J. Tschaplinski i K. J. Hall. "Effects of the abundance of spawning sockeye salmon (Oncorhynchus nerka) on nutrients and algal biomass in forested streams". Canadian Journal of Fisheries and Aquatic Sciences 61, nr 3 (1.03.2004): 384–403. http://dx.doi.org/10.1139/f03-172.
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We used natural variation in sockeye salmon (Oncorhynchus nerka) spawner biomass among sites and years in three undisturbed, forested watersheds in interior British Columbia to test the hypotheses that salmon were a major source of particulate organic matter inputs to the streams and that carcass biomass determined stream-water nutrient concentrations and epilithic algal production. Sockeye carcasses were retained at the spawning sites, primarily (7580%) by large woody debris (LWD) or pools formed by LWD. The abundance and distribution of sockeye salmon determined stream-water nutrient concentrations and epilithic chlorophyll a concentrations during late summer and early fall when most primary production occurred in the oligotrophic streams. Periphyton accrual rates were elevated at sites with high salmon biomass. Peak chlorophyll a concentration increased with increasing carcass biomass per unit discharge above a threshold value to reach maxima 10-fold greater than ambient levels. Epilithic algae were dominated by a few common, large diatom taxa. Salmon carcasses were the dominant source of particulate organic carbon in low gradient stream reaches. Nutrient budget modeling indicated that most of the salmon-origin nutrients were exported from the spawning streams or removed to the terrestrial ecosystem; diffuse impacts may extend over a much larger area than simply the sites used for spawning.
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Alarcon, Vladimir J., i Gretchen F. Sassenrath. "Nitrate, Total Ammonia, and Total Suspended Sediments Modeling for the Mobile River Watershed". International Journal of Agricultural and Environmental Information Systems 8, nr 2 (kwiecień 2017): 20–31. http://dx.doi.org/10.4018/ijaeis.2017040102.
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This paper presents details of a water quality model of the Mobile River watershed that estimates total suspended sediments at the outlet of the watershed. The model is capable of simulating Nitrate (NO3), Total Ammonia (TAM), and Total Suspended Sediments (TSS) for extended periods of time at a daily temporal resolution (1970-1995). The Hydrological Simulation Program Fortran is used for modeling the hydrological, nitrogenous constituents, and sediment processes. Based on the nutrient simulation and exploration of the effects of two management practices (filter strips and stream bank stabilization and fencing) on nutrient removal, the resulting sediment model is used to implement the most efficient nutrient management practice and explore its effects on TSS concentrations in the Mobile River. Results show that the implementation of the management practice “stream bank stabilization and fencing” to agricultural lands in sub-watersheds that had intense agricultural activities produced the highest reductions of NO3 concentration (up to 14.06%) and TAM concentrations (8.01%). Based on the nutrient simulation and identification of “stream bank stabilization and fencing” as the most efficient BMP for nutrient concentration reduction, the sediment model was used to explore its effects on TSS concentrations in the Mobile River. Implementing “stream bank stabilization and fencing” produced monthly median TSS concentration reductions ranging from 3.6% to 10.6% in the Mobile River.
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Barrientos-Pérez, Ana Aurora, Maria Mercedes Castillo, Manuel Mendoza-Carranza i Aarón Jarquín-Sánchez. "Developing nutrient criteria for the Grijalva basin, Mexico". Revista Internacional de Contaminación Ambiental 38 (8.11.2022): 493–510. http://dx.doi.org/10.20937/rica.54408.
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Excess nutrient inputs are a major cause of aquatic ecosystem impairment worldwide. Increased total phosphorus (TP) and total nitrogen (TN) concentrations can lead to eutrophication affecting ecosystem functioning and environmental services provided by streams and rivers. Establishing numeric nutrient criteria is a strategy to reduce nutrient inputs into freshwater ecosystems. Our objective was to estimate nutrient concentrations that could be used as guides to establish nutrient criteria for TP and TN in the Grijalva basin, Mexico. We applied the frequency distribution method to water quality monitoring data for subregions (upper, middle, and lower Grijalva) and for the whole basin, considering two stream size categories. Nutrients were also compared among subregions, land uses, and stream sizes. Agriculture and urban areas showed higher nutrient concentrations than other land uses, probably due to the use of fertilizers and inputs of domestic and industrial wastewater. Higher nutrient concentrations were found in the middle Grijalva and in low-order streams. Nutrient concentrations at the 75th percentile for the reference sites were higher than those obtained at the 5th, 16.7th, and 25th percentiles for the general nutrient data, probably due to the high level of human disturbance in the Grijalva basin. Nutrient concentrations at the 25th percentile are probably too high to protect the aquatic ecosystems in the basin, while concentrations at the 5th percentile can be too restrictive for the basin. Based on our results, nutrient concentrations at the 16.7th percentile are proposed as a first approximation for nutrient criteria to protect river systems in the Grijalva basin.
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von Schiller, D., S. Bernal i E. Martí. "Technical Note: A comparison of two empirical approaches to estimate in-stream nutrient net uptake". Biogeosciences Discussions 7, nr 5 (15.10.2010): 7527–42. http://dx.doi.org/10.5194/bgd-7-7527-2010.
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Abstract. To establish the relevance of in-stream processes on nutrient export at catchment scale it is important to accurately estimate whole-reach net nutrient uptake rates that consider both uptake and release processes. Two empirical approaches have been used in the literature to estimate these rates: (a) the mass balance approach, which considers changes in nutrient loads corrected by groundwater inputs between two stream locations separated by a certain distance, and (b) the spiralling approach, which is based on the patterns of longitudinal variation in ambient nutrient concentrations along a reach following the nutrient spiralling concept. In this study, we compared the estimates of in-stream net nutrient uptake rates of nitrogen (N) and the associated uncertainty obtained with these two approaches at different ambient conditions using a data set of monthly samplings in two contrasting stream reaches during two hydrological years. The rates calculated with the mass balance approach tended to be higher than those calculated with the spiralling approach but only at high ambient N concentrations. Uncertainty associated with these estimates also differed between both approaches, especially for ammonium due to the lack of significant longitudinal patterns in concentration. The advantages and disadvantages of each of the approaches are discussed.
Rozprawy doktorskie na temat "In-stream nutrient concentrations"
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Spahr, Rachel Elizabeth. "Influence of Land Cover, Stream Discharge, and Waste Water Effluent on Suspended Sediment and Nutrient Concentrations in Southwest Ohio Streams". Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1561841165531563.
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Schmitt, Andrea V., i n/a. "The Influence of Nutrients on Aquatic Primary Production and Food Webs in Subtropical Streams of South East Queensland, Australia". Griffith University. Australian School of Environmental Studies, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20061010.135700.
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The increasing world population and with it the increased pressure on food production are likely to challenge the availability of quality fresh water resources in the near future. To compound the looming water crisis, caused by an increased demand for water available for agricultural production, the quality of our fresh water resources is also likely to suffer from the consequences of increased population pressure, i.e. urbanization of land and growth of industries, and food production, i.e. agricultural use of land. Moreton Bay, South East Queensland, Australia, is listed under the United Nations Convention on Wetlands and is also a declared Marine Park. The Moreton Bay area, however, is already one of the five fastest growing urban areas in the developed world. Prognoses about future population growth and urban and industrial development in the area, have hence given rise to growing concerns about the future water quality in this international environmentally important area. Therefore the aim of the current study was to investigate the fate of nutrients in freshwater streams in the Moreton Bay area in order to gain a better understanding of nutrient pathways in aquatic systems and assist in refining the National Water Quality Management Strategy to provide better management of our waterways. To achieve this, the effects of land use on water quality were determined at 22 study sites in the Brisbane River Catchment. Within the catchment five main types of land use were identified, including urban, rural residential, cropping, grazing and mixed types of land use. Water quality was sampled during three seasons: the pre-wet (October - November), wet (December - March) and dry (April - August) season. Nitrogen and phosphorus concentrations in ambient stream water varied significantly spatially, i.e. types of land use, and temporally, i.e. seasons. At some sites, during certain times of the year, nutrient concentrations were found to exceed the range recommended by the Australian Water Quality guidelines. Nutrient concentrations were particular high in urban areas, especially during the dry season. It was also found that the 15N signatures in aquatic plants, i.e epipelic algae, correlated strongly with in-stream nitrogen concentrations. The large variability of in-stream nutrient concentrations, and the related changes in nitrogen isotopic signatures in aquatic plants, made it obvious to suggest that changes in land use may significantly impact on water quality in the catchment. Other changes in land use, for example riparian vegetation clearing, are also commonly observed in areas under urban, industry and/or agricultural growth pressure. This is of particular concern, given riparian vegetation is important not only in controlling nutrient and other organic matter input into streams, but also in regulating light levels for in-stream primary production. Previously riparian zones have been shown to be a prime source of carbon and energy for aquatic food webs in some studies, whereas other studies suggested the main driver of food webs is in-stream primary production. The current study used stable isotope analysis track carbon and nitrogen pathways through aquatic systems and determine the primary source of carbon and energy in aquatic food webs. Despite large spatial and temporal variability of 13C, aquatic consumers were closely tracking the carbon isotope signatures of plants and it was suggested that epilithic and epipelic algae are the main contributors to the carbon and energy budget of aquatic consumers.In realizing this importance of algae in aquatic systems, the next step in this study was to examine the relative importance of light and nutrient availability to periphyton and the effects of changes of these variables on plant biomass and primary production. In an in-situ experiment the levels of light and nutrients available to periphyton, were altered. Although nutrients and light may have colimited standing crop of periphyton, other variables were clearly limited by light. Parallel to this experiment on periphyton, the nutrient availability to Vallisneria spp. was experimentally altered to investigate the effects of changes in nutrient availability and nutrient limitation on other aquatic plants. The biomass of this submerged macrophyte increased three-fold in nitrogen and phosphorus sufficient areas over nutrient limited treatments. The physiological response, i.e. changes in concentrations of amino acids, of periphyton to changes in environmental conditions was also investigated on a large scale, i.e. spatial and temporal variability of amino acids, and a local scale, i.e. amino acid changes in artificially altered light and nutrient availability. This response was of particular interest in this study, as it was previously shown that physiological changes in plants impact on the quality of plants as food for consumers. The physiological changes in aquatic plants could thus provide an important link between nutrient input into streams (e.g. from terrestrial sources), impacts on aquatic plants (e.g.. nutrient uptake and physiological responses in plants) and effects on aquatic consumers (e.g. changes in food quality of plants and therefore impacts on biomass, growth and overall health of aquatic consumers).
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Schmitt, Andrea V. "The Influence of Nutrients on Aquatic Primary Production and Food Webs in Subtropical Streams of South East Queensland, Australia". Thesis, Griffith University, 2005. http://hdl.handle.net/10072/367645.
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The increasing world population and with it the increased pressure on food production are likely to challenge the availability of quality fresh water resources in the near future. To compound the looming water crisis, caused by an increased demand for water available for agricultural production, the quality of our fresh water resources is also likely to suffer from the consequences of increased population pressure, i.e. urbanization of land and growth of industries, and food production, i.e. agricultural use of land. Moreton Bay, South East Queensland, Australia, is listed under the United Nations Convention on Wetlands and is also a declared Marine Park. The Moreton Bay area, however, is already one of the five fastest growing urban areas in the developed world. Prognoses about future population growth and urban and industrial development in the area, have hence given rise to growing concerns about the future water quality in this international environmentally important area. Therefore the aim of the current study was to investigate the fate of nutrients in freshwater streams in the Moreton Bay area in order to gain a better understanding of nutrient pathways in aquatic systems and assist in refining the National Water Quality Management Strategy to provide better management of our waterways. To achieve this, the effects of land use on water quality were determined at 22 study sites in the Brisbane River Catchment. Within the catchment five main types of land use were identified, including urban, rural residential, cropping, grazing and mixed types of land use. Water quality was sampled during three seasons: the pre-wet (October - November), wet (December - March) and dry (April - August) season. Nitrogen and phosphorus concentrations in ambient stream water varied significantly spatially, i.e. types of land use, and temporally, i.e. seasons. At some sites, during certain times of the year, nutrient concentrations were found to exceed the range recommended by the Australian Water Quality guidelines. Nutrient concentrations were particular high in urban areas, especially during the dry season. It was also found that the 15N signatures in aquatic plants, i.e epipelic algae, correlated strongly with in-stream nitrogen concentrations. The large variability of in-stream nutrient concentrations, and the related changes in nitrogen isotopic signatures in aquatic plants, made it obvious to suggest that changes in land use may significantly impact on water quality in the catchment. Other changes in land use, for example riparian vegetation clearing, are also commonly observed in areas under urban, industry and/or agricultural growth pressure. This is of particular concern, given riparian vegetation is important not only in controlling nutrient and other organic matter input into streams, but also in regulating light levels for in-stream primary production. Previously riparian zones have been shown to be a prime source of carbon and energy for aquatic food webs in some studies, whereas other studies suggested the main driver of food webs is in-stream primary production. The current study used stable isotope analysis track carbon and nitrogen pathways through aquatic systems and determine the primary source of carbon and energy in aquatic food webs. Despite large spatial and temporal variability of 13C, aquatic consumers were closely tracking the carbon isotope signatures of plants and it was suggested that epilithic and epipelic algae are the main contributors to the carbon and energy budget of aquatic consumers.In realizing this importance of algae in aquatic systems, the next step in this study was to examine the relative importance of light and nutrient availability to periphyton and the effects of changes of these variables on plant biomass and primary production. In an in-situ experiment the levels of light and nutrients available to periphyton, were altered. Although nutrients and light may have colimited standing crop of periphyton, other variables were clearly limited by light. Parallel to this experiment on periphyton, the nutrient availability to Vallisneria spp. was experimentally altered to investigate the effects of changes in nutrient availability and nutrient limitation on other aquatic plants. The biomass of this submerged macrophyte increased three-fold in nitrogen and phosphorus sufficient areas over nutrient limited treatments. The physiological response, i.e. changes in concentrations of amino acids, of periphyton to changes in environmental conditions was also investigated on a large scale, i.e. spatial and temporal variability of amino acids, and a local scale, i.e. amino acid changes in artificially altered light and nutrient availability. This response was of particular interest in this study, as it was previously shown that physiological changes in plants impact on the quality of plants as food for consumers. The physiological changes in aquatic plants could thus provide an important link between nutrient input into streams (e.g. from terrestrial sources), impacts on aquatic plants (e.g.. nutrient uptake and physiological responses in plants) and effects on aquatic consumers (e.g. changes in food quality of plants and therefore impacts on biomass, growth and overall health of aquatic consumers).Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
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Meininger, William Scott. "The influence of contemporary forest management on stream nutrient concentrations in an industrialized forest in the Oregon Cascades". Thesis, 2011. http://hdl.handle.net/1957/27062.
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The increased demand for wood and fiber from a continually shrinking land base has resulted in the use of intensively managed forest plantations. The concentration of timber production on the most suitable sites allows the world's demand for forest products to be met on less land and enable native forests to be conserved. Because much of the water flowing in rivers in the U.S. originates as precipitation in forests, there is a justified concern about the impacts of forest management on water quality.
Nutrient concentrations were measured in eight streams from October 2002 to September 2011 to assess nutrient response to contemporary forest practices at the Hinkle Creek Paired Watershed Study in the Oregon Cascades. This period of time included a two-year pre-treatment calibration between control and treatment watersheds, a fertilization treatment of both basins in October 2004, and a post-treatment period from 2005 to 2011. A treatment schedule comprised of two temporally explicit harvest entries was used to assess the effects of clearcutting at the non-fish-bearing headwater scale and the fish-bearing watershed scale. Stream water samples were analyzed for nitrogen, phosphorus, calcium, sodium, potassium, magnesium, sulfate, chloride, and silicon as well as specific conductance, pH, and alkalinity. Programmable water samplers were used to take water samples during fall
freshets in November 2009 to assess the stream water discharge versus NO₃ + NO₂ concentration relationship.
All treatment watersheds showed a statistically significant increase in NO₃ + NO₂ concentrations after clearcutting (p < 0.001). The slope of the streambed through the disturbance was a stronger predictor of the magnitude of the response than was the magnitude of disturbance. Ammonia and organic nitrogen displayed notable increases after harvest treatment, but these increases were attributed to increases in the control watersheds. Phosphorus showed a response to timber harvest in one headwater stream. The remaining nutrients showed a small decrease in the control and treatment watersheds for the period after harvest. There was some evidence to suggest that the addition of urea nitrogen to both basins may have caused an increase in in-stream biota uptake of these nutrients. The storm response results showed that NO₃ + NO₂ concentrations in stream water increase with discharge during small storms that occur after periods of negligible precipitation.
Concentrations of NO₃ + NO₂ observed during the calibration period were similar to concentrations observed in an old-growth forest in the H.J. Andrews, suggesting that nutrient processing within the Hinkle Creek watershed had returned to levels that existed prior to its initial harvest sixty years ago. This finding helps to assess long-term impacts of shorter rotation timber harvest of regenerated Douglas-fir stands characteristic of industrialized timber harvest in Oregon.Graduation date: 2012
Książki na temat "In-stream nutrient concentrations"
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M, Robertson Dale. Nutrient concentrations and their relations to the biotic integrity of nonwadeable rivers in Wisconsin. Reston, Va: U.S. Dept. of the Interior, U.S. Geological Survey, 2008.
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Concentrations of selected herbicides, two triazine metabolites, and nutrients in storm runoff from nine stream basins in the midwestern United States, 1990-92. Lawrence, Kan: U.S. Dept. of the Interior, U.S. Geological Survey, 1994.
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Vuorinen, Ilppo. Post-Glacial Baltic Sea Ecosystems. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.675.
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Post-glacial aquatic ecosystems in Eurasia and North America, such as the Baltic Sea, evolved in the freshwater, brackish, and marine environments that fringed the melting glaciers. Warming of the climate initiated sea level and land rise and subsequent changes in aquatic ecosystems. Seminal ideas on ancient developing ecosystems were based on findings in Swedish large lakes of species that had arrived there from adjacent glacial freshwater or marine environments and established populations which have survived up to the present day. An ecosystem of the first freshwater stage, the Baltic Ice Lake initially consisted of ice-associated biota. Subsequent aquatic environments, the Yoldia Sea, the Ancylus Lake, the Litorina Sea, and the Mya Sea, are all named after mollusc trace fossils. These often convey information on the geologic period in question and indicate some physical and chemical characteristics of their environment. The ecosystems of various Baltic Sea stages are regulated primarily by temperature and freshwater runoff (which affects directly and indirectly both salinity and nutrient concentrations). Key ecological environmental factors, such as temperature, salinity, and nutrient levels, not only change seasonally but are also subject to long-term changes (due to astronomical factors) and shorter disturbances, for example, a warm period that essentially formed the Yoldia Sea, and more recently the “Little Ice Age” (which terminated the Viking settlement in Iceland).There is no direct way to study the post-Holocene Baltic Sea stages, but findings in geological samples of ecological keystone species (which may form a physical environment for other species to dwell in and/or largely determine the function of an ecosystem) can indicate ancient large-scale ecosystem features and changes. Such changes have included, for example, development of an initially turbid glacial meltwater to clearer water with increasing primary production (enhanced also by warmer temperatures), eventually leading to self-shading and other consequences of anthropogenic eutrophication (nutrient-rich conditions). Furthermore, the development in the last century from oligotrophic (nutrient-poor) to eutrophic conditions also included shifts between the grazing chain (which include large predators, e.g., piscivorous fish, mammals, and birds at the top of the food chain) and the microbial loop (filtering top predators such as jellyfish). Another large-scale change has been a succession from low (freshwater glacier lake) biodiversity to increased (brackish and marine) biodiversity. The present-day Baltic Sea ecosystem is a direct descendant of the more marine Litorina Sea, which marks the beginning of the transition from a primeval ecosystem to one regulated by humans. The recent Baltic Sea is characterized by high concentrations of pollutants and nutrients, a shift from perennial to annual macrophytes (and more rapid nutrient cycling), and an increasing rate of invasion by non-native species. Thus, an increasing pace of anthropogenic ecological change has been a prominent trend in the Baltic Sea ecosystem since the Ancylus Lake.Future development is in the first place dependent on regional factors, such as salinity, which is regulated by sea and land level changes and the climate, and runoff, which controls both salinity and the leaching of nutrients to the sea. However, uncertainties abound, for example the future development of the Gulf Stream and its associated westerly winds, which support the sub-boreal ecosystems, both terrestrial and aquatic, in the Baltic Sea area. Thus, extensive sophisticated, cross-disciplinary modeling is needed to foresee whether the Baltic Sea will develop toward a freshwater or marine ecosystem, set in a sub-boreal, boreal, or arctic climate.
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E, Spahr Norman, Geological Survey (U.S.) i National Water-Quality Assessment Program (U.S.), red. Development and application of regression models for estimating nutrient concentrations in streams of the conterminous United States, 1992-2001. Reston, Va: U.S. Geological Survey, 2009.
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Development and application of regression models for estimating nutrient concentrations in streams of the conterminous United States, 1992-2001. Reston, Va: U.S. Geological Survey, 2009.
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Development and application of regression models for estimating nutrient concentrations in streams of the conterminous United States, 1992-2001. Reston, Va: U.S. Geological Survey, 2009.
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A, Scribner Elisabeth, i Geological Survey (U.S.), red. Concentrations of selected herbicides, two triazine metabolites, and nutrients in storm runoff from nine stream basins in the midwestern United States, 1990-92. Lawrence, Kan: U.S. Geological Survey, 1994.
Znajdź pełny tekst źródłaCzęści książek na temat "In-stream nutrient concentrations"
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"Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity". W Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity, redaktorzy Kenneth I. Ashley i John G. Stockner. American Fisheries Society, 2003. http://dx.doi.org/10.47886/9781888569445.ch18.
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<em>Abstract</em>. The depressed status of many Pacific Northwest (PNW) salmonid stocks has focused considerable attention on the role of marine-derived nutrients (MDN) in maintaining the productivity of salmonid ecosystems and created a strong interest in stream and lake enrichment as an important salmon restoration technique. This paper reviews some of the technical and more applied aspects of stream, river, and lake enrichment as currently practiced in British Columbia and elsewhere in the world. The first step when considering potential stream and lake enrichment is to determine the ambient nutrient concentrations, stock of biogenic biomass, and trophic status of the candidate ecosystem by conducting nutrient bioassays, synoptic surveys, low-level nutrient analyses, and qualitative assessments of the ecosystems. Phosphorus is considered limiting when concentrations in composite stream or epilimnetic lake samples during the growing season are less than 1µg/L SRP and less than 2–3 µg/L TDP. Nitrogen is considered limiting in streams when dissolved inorganic nitrogen (DIN) concentrations during the growing season are less than 20 µg/L and in lakes when spring epilimnetic concentrations are less than 30 µg/L. At minimum, a 1–2 year pre-treatment study is required to determine the nutrient status and requirements of the ecosystem. Water users and regulatory agencies must be notified in advance of plans to add nutrients to rivers, lakes, or streams, and provincial, state, and/or federal permitting processes and guidelines should be followed. All nutrient enrichment programs must consider seven key variables: (1) desired concentration of nutrients, (2) type of nutrients, (3) seasonal timing of application, (4) frequency of nutrient addition, (5) location of application sites, (6) DIN:TDP (total dissolved phosphorus) ratio of nutrients to be added, and (7) application technique. Enrichment programs should attempt to mimic the anadromous salmon ‘nutrient pump’ where applicable and implement a nutrient prescription that assures the production of edible phytoplankton/periphyton and avoids the occurrence of nuisance algae. In addition, sufficient funds should be secured to monitor the ecosystem responses.
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Alarcon, Vladimir J., i Gretchen F. Sassenrath. "Nitrate, Total Ammonia, and Total Suspended Sediments Modeling for the Mobile River Watershed". W Environmental and Agricultural Informatics, 1469–81. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9621-9.ch066.
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This paper presents details of a water quality model of the Mobile River watershed that estimates total suspended sediments at the outlet of the watershed. The model is capable of simulating Nitrate (NO3), Total Ammonia (TAM), and Total Suspended Sediments (TSS) for extended periods of time at a daily temporal resolution (1970-1995). The Hydrological Simulation Program Fortran is used for modeling the hydrological, nitrogenous constituents, and sediment processes. Based on the nutrient simulation and exploration of the effects of two management practices (filter strips and stream bank stabilization and fencing) on nutrient removal, the resulting sediment model is used to implement the most efficient nutrient management practice and explore its effects on TSS concentrations in the Mobile River. Results show that the implementation of the management practice “stream bank stabilization and fencing” to agricultural lands in sub-watersheds that had intense agricultural activities produced the highest reductions of NO3 concentration (up to 14.06%) and TAM concentrations (8.01%). Based on the nutrient simulation and identification of “stream bank stabilization and fencing” as the most efficient BMP for nutrient concentration reduction, the sediment model was used to explore its effects on TSS concentrations in the Mobile River. Implementing “stream bank stabilization and fencing” produced monthly median TSS concentration reductions ranging from 3.6% to 10.6% in the Mobile River.
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"Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity". W Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity, redaktorzy Carol J. Volk, Peter M. Kijfney i Robert L. Edmonds. American Fisheries Society, 2003. http://dx.doi.org/10.47886/9781888569445.ch15.
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<em>Abstract.</em>—One result of clear-cut logging in the Pacific Northwest is that many watersheds are now dominated by riparian stands of red alder <em>Alnus rubra </em>(Bong). This species colonizes disturbed areas quickly and can limit the establishment of coniferous forest species. In the Northwest, inputs of nutrients from decaying salmon carcasses have been reduced with declining salmon runs, and nitrogen-rich red alder litter may provide a critical source of nutrients to streams. We hypothesized that high-nutrient inputs from red alder forests would translate into more productive and nutrient-rich stream ecosystems, compared with streams bordered by coniferous species. Leaf litter inputs and chemistry, surface water chemistry, and seston and periphyton nutrient dynamics were measured in six streams in the Hoh River Watershed on the western Olympic Peninsula, Washington, during 1999–2000; three streams were dominated by riparian red alder and three in old-growth coniferous forest. Litter inputs to a red alder-dominated stream were three times greater than litter into an old-growth stream. Although total carbon concentration was similar, nitrogen concentration of red alder litter was approximately three times greater than coniferous litter. Alder litter concentrations of other limiting elements, such as Ca, Cu, Mg, K, P, and Zn, were also significantly higher than conifer needles. Phosphorus and Mg concentrations of suspended particulate matter were significantly higher in streams dominated by red alder. Periphyton biomass was significantly higher in streams dominated by alder and had increased levels of magnesium. These data suggest that red alder forests may provide important subsidies of limiting elements that fuel food webs in Pacific Northwest streams. This might be especially important in stressed systems, such as those that have experienced drastic resource removal through forest harvesting or reduced salmon runs.
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"Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity". W Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity, redaktorzy Darcie L. Quamme i Patrick A. Slaney. American Fisheries Society, 2003. http://dx.doi.org/10.47886/9781888569445.ch12.
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<em>Abstract.</em>—The relationship between added soluble nutrient concentration and the abundance and taxonomic composition of stream insects was determined in an experiment using streamside troughs. Target phosphorus (P) concentrations were 0, 0.5, 2.5, 5, 10, and 50 µg/L at a N:P ratio of 1:1 (wt.:wt.). All treatments were replicated three times except 50 µg/ L, which was unreplicated. Peak algal biomass (PB) increased with nutrient concentration linearly to 7.4 mg/m<sup>2</sup> at 2.5 mg P/L and reached an asymptote at 9.2 mg/m2 (2.7× the controls) at 10 µg P/L. Adult baetid mayflies increased 2- and 4-fold when caught in drift nets and emergent insect traps, respectively, at a phosphorus concentration of 10 µg/L compared with controls. Numbers of benthic baetids, nemourid, and perlodid stoneflies and hydroptilid and polycentripodid trichopterans increased 1.6, 2.3, 2.9, 2.8, and 1.2-fold, respectively, at 10 µg P/L compared with controls. Adult and nymphal baetids and benthic nemourids, perlodids, and hydroptilids initially increased rapidly at nutrient concentrations of 0–2.5 µg P/L and reached asymptotes at concentrations of 2.5–10 µg P/L. Exclusion of insects from a single unfertilized trough suggested that grazing limited peak biomass of periphyton to low levels. Increased abundances of aquatic insects resulted from greater periphyton availability at relatively low dissolved-nutrient additions ranging from 0.5 to 10 µg P/L.
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"Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity". W Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity, redaktorzy Thomas C. O’Keefe i Rick T. Edwards. American Fisheries Society, 2003. http://dx.doi.org/10.47886/9781888569445.ch8.
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<em>Abstract.</em>—Evidence for the importance of marine-derived nutrient (MDN) inputs from spawning salmon to terrestrial and freshwater ecosystems is rapidly accumulating, but the mechanisms by which MDN inputs are transferred and stored within spawning streams and their catchments are poorly understood. Presumed marine isotope signals have been found in riparian vegetation, suggesting that marine nutrients may impact terrestrial plant communities. Studies have suggested that MDN increases stream productivity both immediately after spawning and during the following spring. The peak of many spawning runs occurs at the end of the summer growing season, suggesting that overwinter storage of MDN must be occurring. A potential location for lateral nutrient transfers and overwinter MDN storage is the hyporheic zone within stream channels or in adjacent riparian floodplains. Within Lynx Creek, a sockeyespawning stream in the Wood River Lake drainage in southwestern Alaska, extensive floodplain hyporheic zones occur along spawning reaches. Surface water moves into the floodplain hyporheic zone and flows downstream 70–80 m before returning to the stream. Ambient nutrient concentrations within the surface and hyporheic zone indicate that marine-derived nitrogen and phosphorus entered hyporheic flow paths, where they were rapidly removed from the water during the spawning run. Some marine-derived ammonium was remobilized as nitrate and continued to move, but marine-derived phosphorus was stored for at least the duration of the spawning run. Hyporheic sediments are not scoured by winter floods and contain active heterotrophic biological communities that are capable of storing and transforming various forms of MDN. Thus, it seems likely that hyporheic storage and re-release of marinederived nutrients is an important mechanism by which salmon-derived nutrients are retained over winter within stream ecosystems and subsequently made available to primary producers the following growing season.
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"Island in the Stream: Oceanography and Fisheries of the Charleston Bump". W Island in the Stream: Oceanography and Fisheries of the Charleston Bump, redaktorzy John J. Govoni i Jonathan A. Hare. American Fisheries Society, 2001. http://dx.doi.org/10.47886/9781888569230.ch7.
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<em> Abstract.</em>—The region of the outer continental shelf and upper slope, encompassed roughly by 32 and 33°N and 78 and 79°W, is unique within the southeastern Atlantic coast of the United States because of the frequent presence of large (amplitudes of 50-100 km), cyclonic eddies. These eddies develop continuously north of the deflection of the Gulf Stream at the Charleston Bump and decay downstream. The cyclonic circulation of these eddies brings nutrient-rich water from deep and off the shelf edge to near surface and results in enhanced primary production. Succession of Zooplankton assemblages, driven by enhanced primary production, might serve fish production by providing an exceptional, and more continuous food supply for larval fishes spawned in or entrained into eddies. In addition, larval fishes that risk entrainment into the Gulf Stream and consequent loss from local populations, can be retained on, or near, the shelf when embedded within these eddies. The residence of an eddy within the region ranges from a week to a month or two, while the larval period of most fishes ranges from weeks to months. The large-scale eddies in the region develop most frequently in winter when the Gulf Stream is in its strongly deflected mode, coincident with the spawning of a suite of commercially important fishes. Although the region of the Charleston Gyre has the potential to act as an important spawning and nursery habitat, published evidence of usage of the habitat afforded by large scale eddies in this region is weak. High concentrations of larval fishes occasionally occur in the region, but there is no indication of high concentrations of fish eggs. With its high primary and secondary production, succession of Zooplankton assemblages, and retention mechanism, the region of the Gyre may constitute an important spawning and nursery habitat for fishes, but more research aimed at assessing this potential is necessary.
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"Landscape Influences on Stream Habitats and Biological Assemblages". W Landscape Influences on Stream Habitats and Biological Assemblages, redaktorzy Philip R. Kaufmann, Robert M. Hughes i Robert M. Hughes. American Fisheries Society, 2006. http://dx.doi.org/10.47886/9781888569766.ch21.
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<em>Abstract.</em>—Physical habitat degradation has been implicated as a major contributor to the historic decline of salmonids in Pacific Northwest streams. Native aquatic vertebrate assemblages in the Oregon and Washington Coast Range consist primarily of coldwater salmonids, cottids, and amphibians. This region has a dynamic natural disturbance regime, in which mass failures, debris torrents, fire, and tree-fall are driven by weather but are subject to human alteration. The major land uses in the region are logging, dairy farming, and roads, but there is disagreement concerning the effects of those activities on habitat and fish assemblages. To evaluate those effects, we examined associations among physical and chemical habitat, land use, geomorphology, and aquatic vertebrate assemblage data from a regional survey. In general, those data showed that most variation in aquatic vertebrate assemblage composition and habitat characteristics is predetermined by drainage area, channel slope, and basin lithology. To reveal anthropogenic influences, we first modeled the dominant geomorphic influences on aquatic biotic assemblages and physical habitat in the region. Once those geomorphic controls were factored out, associations with human activities were clarified. Streambed instability and excess fines were associated with riparian disturbance and road density, as was a vertebrate assemblage index of biotic integrity (IBI). Low stream IBI values, reflecting lower abundances of salmonids and other sediment-intolerant and coldwater fish and amphibian taxa, were associated with excess streambed fines, bed instability, higher water temperature, higher dissolved nutrient concentrations, and lack of deep pools and cover complexity. Anthropogenic effects were more pronounced in streams draining erodible sedimentary bedrock than in those draining more resistant volcanic terrain. Our findings suggest that the condition of fish and amphibian assemblages in Coast Range streams would be improved by reducing watershed activities that exacerbate erosion and mass-wasting of sediment; protecting and restoring multilayered structure and large, old trees in riparian zones; and managing landscapes so that large wood is delivered along with sediment in both natural and anthropogenic mass-wasting events. These three measures are likely to increase relative bed stability and decrease excess fines by decreasing sediment inputs and increasing energy-dissipating roughness from inchannel large wood and deep residual pools. Reducing sediment supply and transport to sustainable rates should also ensure adequate future supplies of sediment. In addition, these measures would provide more shade, bankside cover, pool volume, colder water, and more complex habitat structure.
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"The Ecology and Management of Wood in World Rivers". W The Ecology and Management of Wood in World Rivers, redaktor ROBERT E. BILBY. American Fisheries Society, 2003. http://dx.doi.org/10.47886/9781888569568.ch7.
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<em>Abstract.</em>—Wood degradation in freshwater aquatic ecosystems differs from degradation in the terrestrial environment. Oxygen concentration in the interior of wet pieces of wood is not high enough to support fungi, the primary decomposing agents of wood in terrestrial environments. The primary decomposing agents of wood in streams and rivers are bacteria and actinomycetes limited to a thin layer on the surface of the piece. As a result, microbial decomposition of wood proceeds much more slowly in water, and changes in wood properties occur only on the surface. Fragmentation is an important degradation process in streams. Flowing water or abrasion from sediment removes wood softened by microbial action, and several types of invertebrates ingest or construct burrows in the softened, outer layer. Removing the outer layer exposes new surfaces to bacterial colonization. Pieces of wood more than 1,000 years old have been identified in rivers by using dendrochronological and radioisotope techniques, although most wood degrades within 100 years after it enters a stream. Nutrient content of wood is low relative to other types of organic matter. Wood abundance in streams is often an order of magnitude greater than that of other types of organic matter, however. Thus, wood does contain a significant proportion of the nutrients associated with organic matter. Wood also affects the nutrient dynamics of streams by controlling the rate of transport of materials downstream. Wood primarily affects nutrients being transported in a particulate form. Removing wood from a 200-m section of a headwater stream in New Hampshire resulted in a sevenfold increase in the transport of sediment and particulate organic matter the next year. The increase was the combined result of mobilizing stored particulate material and increasing the efficiency with which material in the channel was routed downstream. The effect of wood on material transport influences nutrient availability in many Pacific Northwest streams by retaining salmon carcasses, which contribute significant amounts of N and P to the systems where these fish spawn and die.
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"Challenges for Diadromous Fishes in a Dynamic Global Environment". W Challenges for Diadromous Fishes in a Dynamic Global Environment, redaktorzy Keith H. Nislow i Boyd E. Kynard. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781934874080.ch30.
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<em>Abstract</em>.-The sea lamprey <em>Petromyzon marinus </em>is a widely distributed anadromous species spawning in coastal rivers and streams throughout the north Atlantic basin. In this paper, we review aspects of sea lamprey migration and ecology that relate to the transport of nutrients and materials to and from freshwater ecosystems and provide an example of a long-term study of a native wild population. Several aspects of lamprey life history (rapid growth in marine phase, many adults spawn in upper reaches of small oligotrophic rivers, all adults die after spawning) suggest that anadromous sea lampreys contribute marine-derived nutrients and materials (MDNM) to freshwater ecosystems. We used long-term (20 years) data on spawner abundance, along with literature-derived concentration values, to estimate the import of nutrients and materials to a spawning reach of the Fort River, a tributary of the Connecticut River in western Massachusetts, USA. Sea lamprey imported as much as 0.26 g of P per square meter of stream, as much as of 20% of the total annual P loading to a similar system where a full P budget has been developed. While the MDNM contribution of sea lamprey may be substantial, other aspects of their life history and habitat use may limit the overall magnitude and direction of lamprey influence on freshwater ecosystems. Spawning requirement for rocky substrate within a narrow size range may limit import at the watershed scale. In addition, marine survival rates of less than ~1% will result in a net export of nutrients and materials via out-migrating juveniles (transformers). While there is currently no information on survival rates in wild anadromous populations, the tight link between adult survival and prey/host fish populations observed in landlocked Great Lakes systems suggests that the ecological role of sea lamprey may be strongly related to the abundance of coastal marine fishes. Further research on adult survival, juvenile dispersal and distribution, and the paths of nutrient and material uptake in spawning streams are necessary to more fully evaluate the role of anadromous sea lamprey in the transport of MDNM.
Streszczenia konferencji na temat "In-stream nutrient concentrations"
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Klara Reder, Ilona Bärlund, Anja Voß, Ellen Kynast, Richard Williams, Olli Malve i Martina Flörke. "European Scenario Studies on Future In-Stream Nutrient Concentrations". W 21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings, May 27-June 1, 2012, Bari, Italy. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2012. http://dx.doi.org/10.13031/2013.41445.
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Mithani, Aijaz Hussain, Eadie Azhar Rosland, M. Aiman Jamaludin, W. Rokiah W Ismail, Maxwell Tommie Lajawi i Irzie Hani A Salam. "Reservoir Souring in Mature Offshore Field Malaysia: Root Cause, Mitigation, and Management of H2S". W Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/32141-ms.
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Abstract The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to close in (few already closed). Hence, the shut-in wells have to be brought on stream and an assessment of souring potential in the field has to be completed. This paper will share our experience in H2S mapping at reservoir-well-facilities modelling, history matching and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field. A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In first phase we performed the analysis on the historical development of H2S throughout the field and developed the concept for possible souring causes. In second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existence knowledge gap. In third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing etc. It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of Sulphur isotope as H2S concentration increases, d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulphate while formation water rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150ppm could be a technically feasible options to mitigate such higher concentration of H2S within allowable facilities limits of H2S.
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Mithani, Aijaz Hussain, Eadie Azhar Rosland, M. Aiman Jamaludin, W. Rokiah W Ismail, Maxwell Tommie Lajawi i Irzie Hani A Salam. "Reservoir Souring in Mature Offshore Field Malaysia: Root Cause, Mitigation, and Management of H2S". W Offshore Technology Conference. OTC, 2022. http://dx.doi.org/10.4043/32141-ms.
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Abstract The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to close in (few already closed). Hence, the shut-in wells have to be brought on stream and an assessment of souring potential in the field has to be completed. This paper will share our experience in H2S mapping at reservoir-well-facilities modelling, history matching and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field. A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In first phase we performed the analysis on the historical development of H2S throughout the field and developed the concept for possible souring causes. In second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existence knowledge gap. In third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing etc. It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of Sulphur isotope as H2S concentration increases, d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulphate while formation water rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150ppm could be a technically feasible options to mitigate such higher concentration of H2S within allowable facilities limits of H2S.
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Mithani, Aijaz Hussain, Eadie Azhar Rosland, M. Aiman Jamaludin, W. Rokiah W Ismail, Maxwell Tommie Lajawi i Irzie Hani A Salam. "Reservoir Souring Simulation and Modelling Study for Field with Long History of Water Injection: History Matching, Prediction". W SPE Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210778-ms.
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Abstract The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to shut in (a few already shut). Hence, to bring these wells on stream an assessment of souring potential in the field is required. This paper is the results of our experience in H2S mapping at reservoir-well-facilities modelling, history matching, and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field. A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In the first phase, we performed the analysis of the historical development of H2S throughout the field and developed the concept for possible souring causes. In the second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existing knowledge gap. In the third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing, etc. It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of a Sulphur isotope as H2S concentration increases, and d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulfate while formation water was rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200 ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150 ppm could be a technically feasible option to mitigate such high concentration of H2S within allowable facilities limits.
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Mengistu Geza i John E McCray. "Modeling the Effect of Population Growth on Stream Nutrient Concentration in Turkey Creek Watershed using the WARMF Model". W Eleventh Individual and Small Community Sewage Systems Conference Proceedings, 20-24 October 2007, Warwick, Rhode Island. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2007. http://dx.doi.org/10.13031/2013.23982.
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Drost, Kevin, Tracie Jackson, Sourabh V. Apte i Roy Haggerty. "RANS Predictions of Turbulent Scalar Transport in Dead Zones of Natural Streams". W ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72380.
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Natural stream systems contain a variety of flow geometries which contain flow separation, turbulent shear layers, and recirculation zones. This work focuses on stream dead zones. Characterized by slower flow and recirculation, dead zones are naturally occurring cutouts in stream banks. These dead zones play an important role in stream nutrient retention and solute transport studies. Previous experimental work has focused on idealized dead zone geometries studied in laboratory flumes. This work studies the capabilities of computational fluid dynamics (CFD) to investigate the scaling relationships between flow parameters of an idealized geometry and the passive scalar exchange rate. The stream geometry can be split into two main regions, the main stream flow and the dead zone. For the base case simulation, the depth-based Reynolds number is 16,000 and the dead zone is 0.5 depths in the flow direction and 7.5 depths in the transverse direction. Dead zone lengths and the main stream velocity were varied. These flow geometries are simulated using RANS turbulence model and the standard k–ω closure. Scalar transport in dead zones is typically modeled as a continuously stirred tank with an exchange coefficient for the interface across the shear layer. This first order model produces an exponential decay of scalar in the dead zone. A two region model is also developed and applied to the RANS results. Various time scales are found to characterize the exchange process. The volumetric time scale varies linearly with the aspect ratio. The simulations showed significant spatial variation in concentration leading to many different time scales. An optimized two region model was found to model these different time scales extremely well.
Raporty organizacyjne na temat "In-stream nutrient concentrations"
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Desiderati, Christopher. Carli Creek Regional Water Quality Project: Assessing Water Quality Improvement at an Urban Stormwater Constructed Wetland. Portland State University, 2022. http://dx.doi.org/10.15760/mem.78.
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Stormwater management is an ongoing challenge in the United States and the world at-large. As state and municipal agencies grapple with conflicting interests like encouraging land development, complying with permits to control stormwater discharges, “urban stream syndrome” effects, and charges to steward natural resources for the long-term, some agencies may turn to constructed wetlands (CWs) as aesthetically pleasing and functional natural analogs for attenuating pollution delivered by stormwater runoff to rivers and streams. Constructed wetlands retain pollutants via common physical, physicochemical, and biological principles such as settling, adsorption, or plant and algae uptake. The efficacy of constructed wetlands for pollutant attenuation varies depending on many factors such as flow rate, pollutant loading, maintenance practices, and design features. In 2018, the culmination of efforts by Clackamas Water Environment Services and others led to the opening of the Carli Creek Water Quality Project, a 15-acre constructed wetland adjacent to Carli Creek, a small, 3500-ft tributary of the Clackamas River in Clackamas County, OR. The combined creek and constructed wetland drain an industrialized, 438-acre, impervious catchment. The wetland consists of a linear series of a detention pond and three bioretention treatment cells, contributing a combined 1.8 acres of treatment area (a 1:243 ratio with the catchment) and 3.3 acre-feet of total runoff storage. In this study, raw pollutant concentrations in runoff were evaluated against International Stormwater BMP database benchmarks and Oregon Water Quality Criteria. Concentration and mass-based reductions were calculated for 10 specific pollutants and compared to daily precipitation totals from a nearby precipitation station. Mass-based reductions were generally higher for all pollutants, largely due to runoff volume reduction on the treatment terrace. Concentration-based reductions were highly variable, and suggested export of certain pollutants (e.g., ammonia), even when reporting on a mass-basis. Mass load reductions on the terrace for total dissolved solids, nitrate+nitrite, dissolved lead, and dissolved copper were 43.3 ± 10%, 41.9 ± 10%, 36.6 ± 13%, and 43.2 ± 16%, respectively. E. coli saw log-reductions ranging from -1.3 — 3.0 on the terrace, and -1.0 — 1.8 in the creek. Oregon Water Quality Criteria were consistently met at the two in-stream sites on Carli Creek for E. coli with one exception, and for dissolved cadmium, lead, zinc, and copper (with one exception for copper). However, dissolved total solids at the downstream Carli Creek site was above the Willamette River guidance value 100 mg/L roughly 71% of the time. The precipitation record during the study was useful for explaining certain pollutant reductions, as several mechanisms are driven by physical processes, however it was not definitive. The historic rain/snow/ice event in mid-February 2021 appeared to impact mass-based reductions for all metals. Qualitatively, precipitation seemed to have the largest effect on nutrient dynamics, specifically ammonia-nitrogen. Determining exact mechanisms of pollutant removals was outside the scope of this study. An improved flow record, more targeted storm sampling, or more comprehensive nutrient profiles could aid in answering important questions on dominant mechanisms of this new constructed wetland. This study is useful in establishing a framework and baseline for understanding this one-of-a-kind regional stormwater treatment project and pursuing further questions in the future.