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Chan, King-tung. "Multivariate analysis of benthic macroinvertebrate communities of Hong Kong streams /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18037045.
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She, Shu-sheng. "Determinants of macroinvertebrate community structure on stone surfaces in Hong Kong streams /." [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1373149X.
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She, Shu-sheng, and 佘書生. "Determinants of macroinvertebrate community structure on stone surfaces in Hong Kong streams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233879.
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Thursfield, Matthew J. "The effects of acidification on the primary productivity of upland mountain streams." Thesis, Bangor University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261851.
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Lang, Pauline. "Processes driving freshwater plant production and diversity in upland streams." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1864/.
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Upland headwater streams are important sources of freshwater in mountainous temperate to sub-arctic latitude European countries like Scotland. Yet much less is known about the ecology of small, characteristically oligotrophic, mountain streams supporting periphyton and aquatic bryophyte dominated vegetation, and their potential bioindicator capacity of environmental water quality, than lowland rivers impacted by anthropogenic disturbance, in this context. This scarcity of knowledge has significant implications for the success of the recently implemented Water Framework Directive (WFD: 2000/60/EC). The WFD is a major piece of environmental legislation for water policy and sustainable water management in Europe. New contributions are fundamental to environment agencies, such as the Scottish Environment Protection Agency (SEPA), tasked with the responsibility of enforcing WFD statutory requirements and developing effective biomonitoring tools for assessing water quality status in Scotland. A major aim of the WFD is to achieve at least ‘good’ ecological status of inland waterbodies by 2015. Further, in doing so, to ascertain ecological benchmark communities of near-pristine (or minimally-impacted) reference conditions as indicators of high water quality status. The objective is to improve understanding of the environmental processes driving the production and diversity of freshwater plant species-assemblages in upland streams. Such information can be used for assessing perturbations threatening the ecological integrity of rivers impacted by anthropogenic disturbances (human pressure). This enables environment agencies such as SEPA, to respond appropriately by implementing corrective measures and sustainable management strategies. This project monitored a range of near-pristine headwater streams of contrasting underlying geology in the Scottish Highlands. The approach adopted was compatible with current WFD river characterisation and biomonitoring strategies. These were used to investigate the structural and functional response of freshwater plant communities (chiefly diatoms and other algal groups; aquatic bryophyte and vascular submerged macrophyte vegetation) to environmental drivers (e.g. flow, substrate morphology, nutrient inputs, water chemistry, underwater light availability). The work was carried out with the aim of contributing to future development of baseline monitoring tools for assessing upland stream habitat quality in Scotland.
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Cariss, Helen. "Enhancement of invertebrate assemblages in conifer forest streams." Thesis, Manchester Metropolitan University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284877.
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Chan, King-tung, and 陳勁東. "Multivariate analysis of benthic macroinvertebrate communities of HongKong streams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31213911.
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Pretty, James L. "Detritus retention and invertebrate communities in forestry impacted streams." Thesis, Manchester Metropolitan University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323849.
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Ahmad, Amirrudin Bin. "Biological diversity of freshwater fishes in small streams in peninsular Malaysia." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3144.
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Peninsular Malaysia has a diverse flora and fauna, much of which is yet to be documented. The freshwater fishes are one important group that have received little attention. Accordingly, the overarching goal of my study is to investigate the pattern of species richness and analyse the community composition and assemblage structure of fishes in the small streams in Peninsular Malaysia. Small stream habitats appeared to be particularly important repositories of fish biodiversity in this region thus obtaining a reliable census of species occurring in such habitats is critical for conservation and management of biodiversity. Although samplings were far from completed, these habitats support a great variety of species with more than 100 species were recorded from fifty streams sampled in this study. A few are extremely rare with restricted distribution and can thus be considered important in biodiversity conservation of the Peninsular Malaysian ichthyofauna. Human-influenced modification of lowland, headwater stream habitats in Peninsular Malaysia is common and often exemplified by the creation of pools in stretches of rapids and riffles. However, it was not possible to separate pristine and disturbed sites which contained almost identical for species diversity. These findings suggest that local habitat modification does not necessarily cause a decrease in freshwater fish diversity, with only minor negative consequences for other community variables recorded in this study, and therefore raise interesting issues regarding conservation. That said it remains premature to conclude that small stream fishes are insensitive to disturbance and thus their potential utility as bioindicators of disturbance-influenced community changes remain to be confirmed. The maintenance practises being applied to small streams modified for recreational usage were not imposing detectable negative consequences, at least across the sites sampled in this study. The rich diversity of tropical stream environments is the result of both within-habitat (alpha) diversity and between-habitat (beta) diversity. The results showed that there was substantial beta diversity particularly amongst sites that are geographically separated from one another. On the contrary, the lowest beta diversity values were portrayed by contiguous sites. Many fishes exhibited discontinuous patterns of distribution and were considered to be rare while only a handful were widely distributed and abundant. Ordination based on the relative resemblance of fish communities to one another support the existence of two distinct ichthyogeographic divisions in Peninsular Malaysia. It was possible to assign the species recorded to all seven of Rabinowitz's categories of rarity, with at least 10 restricted to a single stream and locally scarce, although not all of these could be described as hyper-endemic. It is recommended that a sizeable augmentation of the existing protected areas is needed to safeguard Malaysia's exceptionally diverse stream-dwelling fauna of which fishes are simply the most well-known inhabitants. Conservation managers should therefore place particular emphasis on small streams since localities in close proximity to one another can exhibit surprisingly high beta diversity, meaning that partial or small-scale habitat protection may prove insufficient.
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Aldridge, Brenda Michelle Te Aroha. "Restoring giant kokopu (Galaxias argenteus) populations in Hamilton's urban streams." The University of Waikato, 2008. http://hdl.handle.net/10289/2516.
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In this study, options for restoring fish populations in Hamilton City (37.47'S, 175.19'E) were explored. Habitat and fish populations in Hamilton urban streams were manipulated using a two-fold experimental design. Firstly, habitat was enhanced in ten urban streams with three continuous treatments in a 60-m reach at each site (20 m with 10 ponga logs, 20 m with 20 hollow clay pipes, and 20 m with no added structure). Secondly, juvenile farm-reared giant kokopu (Galaxias argenteus), were stocked into five of the enhanced stream sections. Giant kokopu are threatened and occur naturally in Hamilton urban streams in sparse populations. The abundance of wild fish was monitored before and after enhancement and fish release from November 2006 to November 2007. Stocked fish were monitored for eight months, from April to November 2007. Over this time electric fishing was conducted three times, trap nets (Gee minnow and fyke nets) were set monthly and spotlighting was conducted monthly at three release sites where water clarity allowed. Anticipated outcomes of this research were; to determine whether giant kokopu abundance in Hamilton urban streams is limited by recruitment or by habitat, and to assist with the development of methods to restore fish populations in Hamilton City urban streams. Logs used as enhancement structures in Hamilton urban streams provided more stable habitat for fish and created more suitable microhabitat than pipe structures. Pipes moved considerably during high flows, and their instability made them less effective at providing habitat. Within the study sites there appeared to be complex interactions with turbidity, stream width and depth, which complicated the effect of the habitat structures. The limited replication and variability among sites contributed to statistically insignificant results using analysis of variance. Retention and recapture rates of stocked juvenile giant kokopu were greatest at Site M11, where the stream was narrow, shallow, clear and had lower numbers and biomass of shortfin eels, compared to other survey sites. Marked and released giant kokopu were retained in the release reaches at four of the five sites, for a minimum of four months, and exhibited substantial growth. Daily growth of juvenile giant kokopu ranged from 0.19 to 0.33 mm day-1 and from 0.03 to 0.11 g day-1, exhibiting substantial growth over winter. Giant kokopu appeared to have a slight bias to the log section of enhanced habitat, but habitat selection appeared to be overwhelmingly controlled by initial habitat selection. The stocking of farm-reared fish into urban streams was largely successful, but the success of the habitat enhancement was variable and further work is required to determine better techniques for habitat enhancement in these urban environments. It is concluded that releasing farm-reared giant kokopu can be used to restore populations especially where recruitment limitations control fish abundance and diversity.
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Decker, Emilia. "Ecoacoustics as a sustainable tool to characterize, investigate and monitor freshwater streams." Thesis, Griffith University, 2021. http://hdl.handle.net/10072/405193.
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Freshwater systems are dramatically transformed by human activities and are in need of effective monitoring to halt the decline of ecosystem health. Ecoacoustics presents a new cost effective way to monitor changes in ecosystems by investigating sounds and their relationships with the environment. However, while ecoacoustics has been explored as a monitoring tool in terrestrial and marine realms, it only gained traction in recent years in freshwater systems.
In this thesis, I investigate ecoacoustics as a monitoring tool for freshwater systems. By investigating spatial-temporal variation in soundscapes of this realm (Chapter 2), examining the main biological drivers of these soundscapes (Chapter 3) and relating acoustic properties to environmental parameters (Chapter 4), I provide comprehensive studies on how freshwater soundscapes change and how ecoacoustics can be used as a monitoring tool.
In the first study (Chapter 2), I characterize soundscapes across multiple freshwater streams, classify these streams according to their soundscape and use acoustic indices to describe spatial-temporal variation of freshwater soundscapes. The results demonstrate that soundscapes in 12 freshwater streams can be highly variable in both space and time. Even among similar streams in the same region, soundscapes differ greatly. Further all 12 streams used in this thesis have a unique soundscape with most differences between soundscapes being observed during the daytime.
For the second study, I manually annotated biological sounds from the 12 freshwater streams analysed in the previous study. Results demonstrate high level of spatial and temporal variation in sound composition between streams with each stream containing a unique sound composition. The sound composition in each stream exhibits a daily cycle with site-specific sequences of sonic activity. Further, sound types are partitioned into temporal, frequency and spatial niches which aligns with the acoustic niche hypothesis.
In my last study I relate acoustic properties of 12 freshwater streams to their environmental parameters. In particular, I explore the relationship between acoustic indices from Chapter 2, annotated biological sounds from Chapter 3 and environmental parameters of each stream. Further I investigate 1) the capacity of acoustic indices to detect biological sounds and 2) biological sounds and acoustic indices as potential monitoring tool for environmental parameters in freshwater streams. Results demonstrate that flow, depth and macrophyte cover are the key drivers of sound composition and that acoustic indices can be used to detect biological sounds and reflect environmental parameters in freshwater streams.
Very few studies have explored soundscapes of freshwater bodies over a broad spatial and temporal scale. Overall, my thesis represents an important first step towards monitoring and analysing freshwater soundscapes. Soundscapes of freshwater streams exhibit spatial-temporal variation and are unique in their sound composition. This suggests that there is a great potential for ecoacoustics to provide a monitoring tool for freshwater systems, especially through easy and efficient use of acoustic indices. However, more research should investigate automated process to extract more acoustic information by using machine learning. My research expands our knowledge of freshwater acoustics and ecoacoustics as a cost effective long-term monitoring tool.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Wilson, Michael. "Organic matter dynamics in willow and eucalypt lined central Victorian streams." Thesis, The Author [Mt. Helen, Vic.] :, 2001. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/69168.
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The spread of exotic willows (Salix spp.) in SE Australia, New Zealand and South Africa has provoked widespread debate in scientific, management and broader communities. In Australia, the extent of spread is unknown, but at least 30000 km of river frontage in Victoria are lined by willows. Management and research literature has identified the poor knowledge of willow impacts on Southern Hemisphere aquatic ecosystems. It has been speculated that the major distinction between deciduous willows and evergreen native vegetation will be the timing and quality of litterfall. This would have flow-on consequences for metabolic processes, stream biota and water quality at reach, stream and catchment scales. These two vegetation types were studied through the preparation of partial organic matter budgets for native and willow lined reaches in a central Victorian catchment. Organic matter inputs from litter, groundwater and gross primary production (GPP), organic matter standing crop . and respiratory output were quantified. Total inputs to willow and native reaches were similar (735 and 764 g ash free dry weight m•' yl, respectively). Inputs were dominated by litterfall (-60%) and there were no significant differences in annual litterfall between sites. GPP contributed -20% of total inputs and estimates suggested there were few significant differences in annual GPP, 24 h community respiration, ratio of GPP to community respiration (PIR) or net daily metabolism (NDM) between sites. Groundwater contributed -20% of total inputs with one third of the dissolved organic matter sourced during short flow paths through riparian sediments. Aggradation at willow sites appeared to increase the riparian flow path. Willow and native sites were heterotrophic and similarly dependent on allochthonous organic matter (P/R=O.2, NDM= -.6, and ratio of net primary production to total inputs -0.1). Willow research and management should also focus on retention capacity, including the recruitment and role of LWD and the structure and function of root systems. Removal of willows potentially facilitates native vegetation establishment but simultaneously decreases retention capacity and metabolic control by the canopy. Establishing native vegetation to fulfil broader biodiversity objectives whilst retaining willows for their potentially positive roles is a management challenge. In principle, establishing native species on the upland-sides of fringing willows and under willow canopies will direct succession toward a preferred outcome without destructive disturbance. Understanding of when benefits of willows outweigh their costs is a notable gap.School of Science & Engineering
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Jackson, Karen. "Influence of Patch-Burn Grazing and Riparian Protection on the Ecological Integrity of Tallgrass Prairie Headwater Streams." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1345.
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Conversion to agriculture, land fragmentation, and removal of native grazers have made tallgrass prairies and the streams that drain them one of the most imperiled systems on earth. Patch-burn grazing (PBG), an increasingly common management practice on remaining prairie parcels, has been shown to benefit cattle and grassland birds. However, potential influences of this practice on streams are unknown. To address this, we sampled stream macroinvertebrates and benthic organic matter two years before and three years during PBG on two watersheds with riparian fencing (fenced), two grazed watersheds without riparian fencing (unfenced), and two ungrazed (control) watersheds. Very fine benthic organic matter increased 51% in unfenced watersheds after implementation of PBG, accompanied by a threefold increase in fine organic sediments in the same watersheds. Contribution of fine inorganic sediments to total substrata increased 28% in unfenced watersheds during PBG, while fine inorganic sediments decreased in both the control (18%) and fenced (16%) watersheds. Increases in the contribution of Chironomidae to total macroinvertebrate abundance (18% before, 49% during PBG) and biomass (10% before, 19% during PBG) were evident in unfenced streams. In contrast, abundance of sensitive EPT taxa decreased an order of magnitude from 7,635 to 687 individuals m-2 in unfenced streams, but did not change in fenced and control streams. Increases in tolerant taxa and fine organic and inorganic sediments, along with reductions in metrics of biotic integrity, suggest PBG adversely impacts prairie streams. However, the absence of negative responses in fenced watersheds indicates that riparian fencing can mitigate these impacts by serving as a buffer to prevent excess sedimentation. In order to properly manage remaining tallgrass prairie parcels, it is important to consider both the aquatic and terrestrial components of these systems, as they are tightly linked. Results from this study provide a basis for management and policy decisions regarding remaining grassland watersheds.
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Custer, Kevin Wayne. "FACTORS CONTROLLING NICKEL BIOAVAILABILITY AND EFFECTS ON BENTHIC INVERTEBRATES IN HARDWATER FRESHWATER STREAMS." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1364295154.
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Brereton, Chris. "The role of mucus and silk as attachment and sorption sites in streams." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313984.
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Yang, Yao. "The ecology of a herbivorous fish (Pseudogastromyzon myersi: balitoridae) and its influence on benthic algal dynamics in four Hong Kong streams." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508646.
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Watson, Troy Norton. "The structuring of aquatic macroinvertebrate communities within cave streams." Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/6513.
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The unusual environmental conditions within caves provided unique opportunities for developing an understanding of ecosystem processes. However, relatively few studies have been conducted on the ecology of New Zealand cave systems. The primary aim of this research was to investigate changes in aquatic invertebrate communities along a longitudinal gradient from the surface into caves and investigate the fundamental drivers of cave communities. This study was carried out in three streams (two in pasture catchments and one in a forested catchment) flowing into caves in the Waitomo region, North Island, New Zealand. In order to address these aims I carried out a longitudinal survey of 12 sites in each stream, an experimental manipulation of food, and an isotopic study of a single stream. The longitudinal survey of the three cave streams revealed light intensity as well as algal and CPOM biomass all decreased significantly from outside the caves into caves. In contrast, water temperature, dissolved oxygen, stream width, depth, and velocity did not vary significantly with distance into caves. Benthic aquatic macroinvertebrate communities within the caves were a depauperate subset of surface communities, appearing to be structured by gradients in resources and colonisation through drift. However, some invertebrate taxa (primarily predators) were rarely found within caves, further suggesting that resource gradients were structuring cave communities. Surprisingly, the densities of some collector-browsers (primarily mayflies) increased within cave streams relative to surface densities. This may be due to a decrease in competition and predation, flexible feeding strategies, and high drift propensity. However, the benthic densities of most taxa within the caves appeared to be related to drift densities. Although surface forest and pastoral stream communities differed in community composition and density 32 meters within the caves invertebrate community diversity and density became similar, although specific taxa within communities varied. This convergence was attributed to similar environmental gradients within the caves. The resource addition experiment (adding leaf packs) indicated that cave streams were resource limited; the addition of leaves produced communities of similar richness and density across the environmental gradient. The isotopic survey suggested cave stream invertebrate communities were reliant upon similar basal resources to surface streams. However, within the cave epilithon appeared to be increasingly important while filamentous algae were absent. Cave
aquatic invertebrates were also found to support terrestrial predators (spiders, harvestmen, and glow-worms), presumably increasing the abundance and diversity of terrestrial cave communities. In conclusion, aquatic cave communities were reliant upon surface derived resources and consequently strongly linked to surface land-use and managerial practices.
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Leung, Sze-lun. "Scale-dependent effects of spatial and temporal variability on benthic macroinvertebrate communities in Hong Kong streams /." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25334542.
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Yu, Songyan. "Spatio-temporal dynamics and hydro-ecology of intermittent streams in eastern Australia." Thesis, Griffith University, 2019. http://hdl.handle.net/10072/389088.
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Intermittent streams that cease to flow for some period of most years are prevalent across global river networks. Their spatial extent is projected to increase in regions experiencing drying trends related to climate change and water extraction for human uses. Intermittent streams sustain biodiversity by hosting a unique combination of aquatic, amphibious, and terrestrial assemblages as a result of their wet and dry phases. Compared to perennial streams, the ecological values of intermittent streams are not well-appreciated or understood, and thus intermittent streams are less commonly incorporated into policy, management, and regulatory decisions. As research on intermittent streams is increasing, there have been strident calls for better recognition and protection of intermittent streams. This thesis aims to develop new methods to address some key issues related to spatio-temporal dynamics and hydro-ecology of intermittent streams, with a focus on eastern Australia.
River channel drying caused by intermittent stream flow is a widely-recognised factor shaping stream ecosystems. There is a strong need to quantify spatio-temporal variations in the hydrology of intermittent streams over broad spatial scales to inform ecological understanding and management. This is challenging because observational stream gauges are sparsely distributed and provide only point estimates of discharge. In this study, I developed models to simulate monthly discharge across river catchments. Due to the common issue of over-estimating low flows in discharge simulations, I also identified appropriate zero flow thresholds to mitigate this uncertainty. I quantified spatial and temporal patterns of flow intermittency for every stream segment within river networks of five major catchments in south-eastern Queensland (SEQ), eastern Australia. Results showed that the temporal dynamics of flow intermittency varied dramatically inter-annually over the period of 1900-2016, with the proportion of intermittent streams ranging in length from 3 % to nearly 100% of river networks, but there was no evidence of an increasing trend towards flow intermittency over this period. This approach to generating spatially explicit and catchment-wide estimates of streamflow intermittency can facilitate improved ecological understanding and management of intermittent streams.
Compared with monthly discharge simulations, daily discharge simulations can provide more detailed representation of the dynamic aspects of hydrological processes and potentially enables more ecologically relevant characterisation of hydrology. However, models of daily stream flow are more complex and often need to take river routing processes into account. I developed models to simulate daily stream flows for contiguous sub-catchments across entire river networks in two hydro-climatically distinctive regions (SEQ vs. the Tamar River
II
catchment). I evaluated the models in terms of their ability to represent different ecologically important components of flow regime and quantified environmental correlates of differences in model accuracy within and between regions. The models showed generally good performance in both regions. However, average- and high flows were better predicted than low flows in SEQ because it is difficult to represent climate and hydrogeological processes influencing the low-flow part of the hydrograph. Spatial variation in flow characteristics revealed the highly dynamic nature of flow permanence in space and time, with intermittent flows affecting between 29% and 80% of the river network over the period of 1911-2017. I discuss the pros and cons of the applications of modelled monthly and daily flows, and conclude that the appropriate choice of modelling time step depends on the primary objectives of the research. The monthly time-step is suitable for quantifying ecologically relevant spatial and temporal variations in streamflow intermittency, but may be insufficient for studies aimed at quantifying ecological responses to short term flow events.
The hydrological variability of intermittent streams poses challenges for resident aquatic biota which require access to permanent surface water-bodies to persist during dry spells and to recolonise suitable habitats when flows resume. However, research to quantify the dynamics and environmental determinants of variation in surface water extent is usually conducted over limited spatial and/or temporal extents. One of the biggest barriers to this kind of research is the difficulty in obtaining observed data of surface water extent across river networks. In this study, I demonstrated a newly-developed field method for rapid surface water assessment, and then developed predictive models relating observed water extent to environmental attributes at 241 surveyed stream segments in SEQ. I used the models to predict daily variations in surface water dynamics throughout entire river networks over the past century, based on available long-term environmental attributes. Descriptors of surface water extent could be accurately modelled, with good internal and external validation performance. Long-term variations in surface water extent were highly dynamic through space and time, although the overall length of river networks with surface water remained relatively stable from year to year. This study provides valuable insights into the potential priority conservation areas for aquatic biota across the study region.
Systematic conservation prioritisation methods are increasingly being applied to freshwater ecosystems to identify candidate areas for ecosystem management and biodiversity protection. However, applications with emphasis on intermittent streams are scarce. The hydrological variability of intermittent streams means that the spatial distribution of dry season aquatic refuges within river networks and the temporal dynamics of hydrological connectivity between them are critical for the persistence of aquatic biodiversity. I developed a new approach to incorporating both surface water persistence and hydrological connectivity into systematic conservation prioritisation in intermittent streams. I also included multiple freshwater fish species distributions as explicit targets for habitat prioritisation, and incorporated estimates of their relative mobility to maximise potentially re-colonisable stream length from refuges. Compared with the situation without mobility, the inclusion of species mobility could significantly reduce the number of aquatic refuges required to meet the set conservation targets. High priority aquatic refuges were widely distributed across the study river networks, encompassing streams in various orders from main stems to headwaters. The research can help enhance both the resistance and resilience of freshwater biodiversity in intermittent stream ecosystems.
The thesis concludes with practical learnings from these modelling studies for intermittent stream research and management, namely, 1) that discharge simulations (monthly or daily) throughout river networks confirmed the prevalence of intermittent streams and revealed the highly dynamic nature of flow intermittency over space and time; 2) that spatial and temporal dynamics of surface water availability within stream reaches can be modelled through the combination of observed surface water extent with long-term environmental attributes; and 3) that systematic prioritisation of aquatic refuges by incorporating both surface water persistence and hydrological connectivity enables to efficiently meet conservation targets for species representation and cost-effective conservation management. The thesis also concludes with future challenges and directions for intermittent stream research.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Högberg, Jan-Olov. "Can GIS be used to identify streams with successful recruitment of freshwater pearlmussels (Margaritifera margaritifera)?" Thesis, Karlstad University, Faculty of Social and Life Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-4696.
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The freshwater pearl mussel (Margaritifera margaritifera) has declined dramatically throughout its range and is faced with recruitment problems in most of the streams where populations still persist. Human activities, such as forestry and agriculture, are thought to be the main reason for these problems. In this study, spatial information on landscape features along 38 streams with known recruitment status were analyzed in an effort to determine if GIS-tools could be used to identify streams with successful recruitment. Differences in the distribution of various landscape features, measured in stream corridors of 50 and 150 m, and differences in several water chemical factors between streams with and without recruitment were investigated. The distribution of landscape features was also compared with host fish (brown trout) density and any statistically significant water chemical factor. Both mussel recruitment and trout density were found to be negatively related to clear-cuts, and mussel recruitment was also negatively related to high water color, which has been shown to be correlated with high nutrient content, one of several adverse effects of clear-cutting close to streams. Recruitment was expected to be negatively affected by roads, but no such relationship could be found. Instead, mussel recruitment was found to be positively related to the number of road crossings per kilometer, but the strength of this relationship was questionable. In addition, even though it was somewhat unclear, high proportions of lakes and ponds were found to be positive for both recruitment and high trout density. The results of the study indicate that GIS-tools can be used to find landscape features that affect recruitment of freshwater pearl mussel and they support the belief that forestry activities are an important cause for the decline of the species in Sweden. In addition, the results indicate that leaving protective zones of forest between streams and clear-cuts can be a possible conservation method for the freshwater pearl mussel.
Flodpärlmusslan (Margaritifera margaritifera) har minskat kraftigt i hela sitt utbredningsområde och i de flesta vattendrag där populationer finns kvar sker ingen rekrytering. Mänskliga aktiviteter, exempelvis skogsbruk och jordbruk, anses vara huvudorsaken för dessa problem. Syftet med den här studien var att undersöka om GIS-verktyg kan användas för att identifiera vattendrag med fungerande rekrytering. För att uppnå det analyserades geografisk information om landskapet längs 38 vattendrag med känd rekryteringsstatus. Skillnader i fördelningen av olika landskapsföreteelser, uppmätt i 50 och 150 meters buffertzoner, och skillnader i flera vattenkemiska faktorer mellan vattendrag med eller utan rekrytering undersöktes. Dessutom undersöktes även om det fanns något förhållande mellan landskapsföreteelser och tätheten av värdfisk (öring) och mellan landskapsföreteelser och signifikanta vattenkemiska faktorer. Både rekrytering av flodpärlmusslor och öringstäthet var negativt relaterad till kalhyggen. Rekrytering var också negativt relaterad till hög vattenfärg, som har visats vara korrelerat med högt näringsinnehåll, en av flera effekter kalhyggen nära vattendrag har. Rekrytering förväntades påverkas negativt av vägar, men inget negativt förhållande hittades. Istället hittades ett positivt förhållande mellan rekrytering och antalet vägkorsningar per kilometer, men styrkan av det förhållandet var ifrågasättbar. Dessutom var, om än något otydligt, andelen sjö och damm positivt för både rekrytering och hög öringtäthet. Studien indikerar att GIS-verktyg kan användas för att hitta landskapsföreteelser som påverkar rekryteringen av flodpärlmusslor och den stödjer bedömningen att skogsbruk är en av de viktigaste anledningarna till artens nedgång i Sverige. Dessutom indikerar resultaten att skyddszoner mellan kalhyggen och vattendrag kan vara en möjlig skyddsåtgärd för flodpärlmusslan.
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Sinton, Amber. "The ecology of freshwater communities of stock water races on the Canterbury Plains." Thesis, University of Canterbury. School of Biological Sciences, 2008. http://hdl.handle.net/10092/2273.
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Agricultural intensification on the Canterbury Plains in New Zealand has lead to the degradation of natural streams and rivers through lowering of water quality and significant reduction of surface flows from the use of ground and surface water resources. However, this same agricultural expansion has led to the development of a network of permanently flowing open water races to supply stock water to farms across the Canterbury Plains. Stock water races form an extensive network, with approximately 6,500 km of races. Initially I surveyed 62 water races and compared habitat characteristics, water quality, benthic invertebrate and fish communities with nearby natural streams. Races are characterised physically by straight, narrow and shallow channels, and small, uniform substrate. Water races are more turbid than natural streams, and can have high summer temperatures. The benthic macroinvertebrate communities of water races contained a range of taxa, including some not found in natural streams, but communities were less diverse than communities in natural streams, and tended to be dominated by a limited set of generalist taxa. A longitudinal study of three water races showed gradients in physical characteristics of races, including a downstream decrease in channel width, water depth, current velocity and substrate size. However, few strong longitudinal changes to community structure were found, as the generalist taxa commonly occurring in water races were able to tolerate conditions throughout the race network. To test if macroinvertebrate communities were limited by the homogeneous habitat of water races, I conducted a substrate manipulation experiment, where large cobbles and small boulders were added to reaches in five water races. Despite an increase in substrate and current heterogeneity, there were few significant changes to the macroinvertebrate communities over the four months of the manipulation. This outcome does not eliminate low habitat heterogeneity as a limiting factor for water race communities. Rather, the benthic invertebrate community throughout the water race network is a product of the homogeneous habitat, which limits the availability of colonists of taxa that would benefit from increased habitat diversity. A survey of the fish assemblages of water races found races had a depauperate fish community. Only two species were commonly found in water races, and the average species richness of races was 1.5. By contrast natural streams had a higher diversity of fish species (mean 4 three species), and contained representatives of a greater number of species that are typical of streams and rivers on the Canterbury Plains. My research has shown that stock water races provide an important source of aquatic biodiversity on the plains, both in addition to natural streams and in their own right. However, the biodiversity value of stock water races could be improved with enhancement of in-stream habitat.
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Begley, Matthew T. "Assessment of the freshwater mussel community of the upper Mahoning River watershed and factors influencing diversity and abundance in small streams." Cleveland State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=csu1421151683.
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Engel, Sarah Rose. "The effectiveness of using volunteers for biological monitoring of streams." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31060.
Full textAbstract:
An increase in public environmental awareness and a decrease in resources within government regulatory agencies have led to a larger interest in volunteer biomonitoring programs. Government agencies are currently using volunteer data for official purposes with increasing frequency, but questions have been raised about the validity of the data collected by volunteers who have only limited training and experience. Therefore, we conducted a detailed study to assess, modify, and validate the Virginia Save-Our-Streams (SOS) program, which is a volunteer organization collecting macroinvertebrate data. Sites were sampled using professional methods concurrently with volunteers who utilized the SOS protocol. The volunteer samples were retained for further laboratory analysis. In addition, numerous sites previously sampled by volunteers were re-sampled using professional methods. The data were statistically analyzed to determine if the results of volunteers and professional aquatic biologists were correlated and if they arrived at the same conclusions about ecological condition. It was determined that the Virginia SOS method, and probably other similar volunteer methods, consistently overrate ecological condition. This means that streams impaired by pollution could go unreported, if they are monitored exclusively by volunteers. The cause of this overestimation was determined to be the overly simplistic SOS metric, which is based solely on the presence or absence of taxa. The SOS protocol for data analysis was made more quantitative by developing a multimetric index that is appropriate for use by volunteers. The SOS sampling protocol was modified slightly to obtain actual counts of the different kinds of macroinvertebrates, which allowed for calculation of metrics. Sorting effort and taxonomic level of identification were not changed so that currently participating volunteers would not be excluded because of the need for expensive equipment or advanced technical training. The modified SOS protocol was evaluated by a different set of concurrent samples taken by volunteers and professionals, but using the same statistical techniques. The modified SOS protocol proved to be feasible for volunteers. The new SOS multimetric index correlated well with a professional multimetric index. The conclusions about ecological condition derived from the volunteer multimetric index agreed very closely with those made by professional aquatic biologists. This study demonstrated that volunteer biomonitoring programs can provide reliable data, but every volunteer program needs to be thoroughly validated by statistical comparisons to the professional methods being used in that area.Master of Science
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Veenstra-Quah, Anneke Alison, and mikewood@deakin edu au. "The impact of stresses imposed on macroinvertebrate communities in two urban streams." Deakin University. School of Biological and Chemical Sciences, 1999. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050815.102219.
Full textAbstract:
The aim of the project was to determine factors which explain the distribution of macroinvertebrates in two Melbourne streams both drastically affected by urbanisation. A detailed description is given of Dandenong Creek, flowing through the south-eastern suburbs, and Darebin Creek, in the northern suburbs, emphasising stream features likely, or known, to influence the drift and benthic fauna.
Faunal sampling was carried out in Dandenong Creek from June 1992 until July 1993, and in Darebin Creek from February 1995 until March 1998. Physicochemical parameters were also recorded. The collected data, together with previously existing data, were analysed using multivariate analyses: non-metric multi-dimensional scaling (NMDS); analysis of similarities (ANOSIM); matching biotic and abiotic variables using BIOENV, and principal component analysis (PCA). Various biotic and diversity indices were calculated in an attempt to identify the major factors responsible for the failure of the fauna to recover from previously more seriously degraded water quality.
The contribution of drift to the colonisation potential in Dandenong Creek appeared to be impacted by retarding basins, underground barrel-draining and channelization. Results also indicated that increased conductivity adversely affected the fauna in the lower reaches of Dandenong Creek. It was concluded that in Darebin Creek, high nutrient levels, as well as other pollutants, had resulted in low macroinvertebrate diversity in both the drift and benthos.
If, as this study suggests, faunal diversity is a valid measure of stream health, the following factors need to be addressed for catchment-wide, stream management: lack of riparian zone vegetation (increasing bank erosion and making the benthic habitat unstable, with greater temperature variability); control of stormwater runoff (flow variability, increased conductivity, nutrient levels, sediment loads, sewage effluent, industrial discharges and heavy metals), and to modify retarding basins to increase stream continuity.
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Hersha, Deborah Kay. "Agricultural Effects on Protists Assemblage Structure in Headwater Streams." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1236463645.
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Nicol, Sandra Diane. "Influence of physical and biological habitat variables on juvenile salmonid and invertebrate drift abundance in southwest British Columbia streams." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/256.
Full textAbstract:
Determining the physical and biological habitat variables that influence the abundance of juvenile salmonids in British Columbia streams will improve management practices. Habitat models are tools that provide insight into organisms’ habitat needs and provide a more efficient mechanism for estimating population abundance than direct measurement. Models have been developed for salmonids in other jurisdictions, but very few have included invertebrate drift (a primary food source for juvenile salmonids) as a predictive variable. This is because temporal and spatial variation of drift abundance are widely assumed to be so high that drift cannot be reliably estimated without unreasonable effort. This thesis investigates the temporal and spatial variability of invertebrate drift and the impact of its inclusion in habitat models for juvenile salmonid abundance in two chapters. The first objective of the first chapter was to evaluate the temporal variability of invertebrate drift by comparing the seasonal and day-to-day variation in drift abundance to spatial variation within and between sites. The second objective was to develop predictive models for invertebrate drift abundance. Aquatic, terrestrial and total invertebrate drift abundances varied primarily between sites and very little between days or months at the same site, indicating that a single day of sampling is sufficient to assess drift abundance for comparison among sites. The abundance of invertebrate drift was related to productivity- and flow-related habitat variables. The objectives of the second chapter were to develop predictive models for juvenile salmonid abundance in southwestern BC using physical and biological habitat variables, to determine whether habitat variables differ between the Coast and Interior regions of BC, to determine the contribution of invertebrate drift to the relative predictive ability of the models, and to determine cost:benefit ratios for the predictive models and their component variables. The final models for predicting abundance of all young-of-year salmonids combined, and rainbow trout (Oncorhynchus mykiss) and coho salmon (O. kisutch) individually, included variables related to stream structure and productivity, and the models for rainbow and coho showed regional differences. Invertebrate drift did not improve model fit.
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Schmitt, Andrea V., and 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.
Full textAbstract:
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.
Full textAbstract:
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
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Törnblom, Johan. "A landscape approach towards ecological integrity of catchments and streams /." UUppsala : Dept. of Forest Products, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200870.pdf.
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Rogers, Megan Bryn. "Woody debris and macroinvertebrate community structure of low-order streams in Colville National Forest, Washington." Connect to this title online, 2003. http://www.dissertations.wsu.edu/Thesis/Fall2003/m%5Frogers%5F121503.pdf.
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Price, David John. "USE OF IN-SITU FISH POPULATIONS FOR BIOMONITORING POLYCHLORINATED BIPHENYL AND METAL POLLUTION IN MODERATELY IMPACTED FRESHWATER STREAMS." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_diss/556.
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Water, sediments, floodplain soils, and fish from Big and Little Bayou creeks were assessed for polychlorinated biphenyls (PCBs) and metals in 1987-2005. The streams were impacted by effluents from the Paducah Gaseous Diffusion Plant (PGDP). PCBs were rarely detected in water samples. Aroclor 1248 detections in sediments and floodplains were sporadic, but 1254 and 1260 were consistent. Seasonal variations were only observed for Aroclor 1248. Detection of PCBs in floodplains indicated recent influx of contaminated sediments. Species-specific PCB residues patterns were studied for Lepomis cyanellus, L. megalotis, L. macrochirus, and Campostoma anomalum. Highest PCB concentrations were found in stoneroller minnows. PCBs decreased over time in sunfish species, but retained a baseline level. No relationships were found between sunfish age and PCB concentrations. At low PCB levels, green sunfish body burden (BB) did not correlate with lipid content. A certain PCB concentration must be exceeded before PCB BB correlates with lipid content. Stream flows differed by season, and fish PCB BB differed by season, but stream flow did not correlate with fish BB. Congener groups corresponded to Aroclor concentrations. Higher chlorinated biphenyls peaked in the spring for sport fish. PCBs remobilized in the spring resulted in higher summer BB for the stoneroller minnows, whereas sunfish eliminated PCBs by summer. This variability was due to the sunfishs ability to regulate PCBs. Metal concentrations did not display the seasonal variability evident in the PCB data. Water metals may have peaked during storm events and decreased rapidly. Water Pb increased with time, but the source could not determined. Zinc in Little Bayou creek likely originated from the PGDP. Except for Cu and Zn, stoneroller minnow metal BB decreased with time. Metal BB were used to determine bioavailable fractions. Less than half of the water column Cd, Cr, Fe, and Pb in impacted areas were bioavailable to stoneroller minnows, whereas 59% of Ag, 73% of Cu, and 64% of Zn were bioavailable. Cumulative criterion units were calculated to determine additive metal impacts, and proved useful in locating sectors with possible ecological impact. In-situ monitors proved valuable in studying PCB and metal behavior under real-world conditions.
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Simon, Matthew Larson. "Sediment and Interstitial Water Toxicity to Freshwater Mussels and the Ecotoxicological Recovery of Remediated Acid Mine Drainage Streams." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34883.
Full textAbstract:
The river drainages originating in the Cumberland region of Virginia, Tennessee and Kentucky are home to some of the last surviving and most diverse assemblages of native freshwater mussels. This region of the country also has historically and continues to be a major source of coal for the United States. Numerous experiments were carried out in an attempt to determine what ecotoxicological effects these activities have had on mussels as well as what has been done to correct some of the most severe cases of environmental pollution due to historical coal mining operations. Analysis of interstitial water (IW), sediment and in situ toxicity testing and chemical analyses showed that the most likely cause for mussel declines was elevated metal concentrations (Al, Cu, Fe, Pb) found in IW. Ecotoxicological assessments of the two streams (Black and Ely Creeks) most impacted by acid mine drainage (AMD) in the state of Virginia were carried out to determine their potential for future degradation of the Powell River watershed into which they drain. The Powell River is a major system still inhabited by native mussels. Sophisticated wetland systems built at Ely Creek have significantly improved the ecological health of Ely Creek, decreasing the pollution into the Powell River. Reclamation and wetland construction at Black Creek have had a positive impact but active coal mining and un-remediated AMD are still negatively affecting this system. After the watershed has been fully reclaimed the discharge from Black Creek will likely be improved.Master of Science
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Yeung, Chee-yu Alex, and 楊智羽. "Population dynamics and secondary production of a dominant molluscan primary consumer, Sulcospira hainanensis (gastropoda : pachychilidae),in Hong Kong streams and their implications for benthic productivity: y Yeung Alex Chee Yu." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B5043455X.
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The lack of any measurements of the secondary production of the prosobranch snail Sulcospira hainanensis (Bröt, 1872) (Pachychilidae), an abundant primary consumer in Hong Kong streams, represents a major gap in our knowledge of the magnitude of benthic productivity in these systems where S. hainanensis constitutes a substantial proportion of community biomass. This study investigated the population dynamics and production of S. hainanensis between February 2011 and February 2012 in 4 Hong Kong streams (2 unshaded and 2 shaded). Annual production by amphibiotic insects was also quantified by emergence traps to evaluate the importance of in-stream production by fully aquatic animals versus that leaving streams in the form of adult aquatic insects. In addition, snail grazing effects on algae and the potential for consequent competitive interactions with benthic insects was compared under different shading conditions and between wet and dry seasons.
Sulcospira hainanensis was ovoviviparous and had balanced sex ratios. Brood size ranged from 52 to 1189, and 3 recruitment episodes were observed in both populations in the one-year study period. Hatchlings reached sexual maturity in 3 – 5 years whereas adults could live for 6 – 12 years. Mean population densities varied from 108.4 to 206.1 individuals m^(-2), while mean biomass was 1003.0 to 4430.2 mg ash-free dry mass (AFDM) m^(-2) and was generally higher in the dry season. Snail production was estimated using the size-frequency, instantaneous-growth (field- and computer-based) and increment-summation (IS) methods, with the IS estimates (1612.8 – 6123.9 mg AFDM m^(-2) 〖year〗^(-1)) considered to most accurately represent production by S. hainanensis. Annual turnover ratios were 1.36 – 2.24 〖year〗^(-1), and production was higher in unshaded streams where growth was more rapid, reflecting higher availability of algal food.
The contribution of S. hainanensis to production by benthic animals as previously estimated in one study site was relatively low (15%) compared with its contribution to total standing biomass (26%). Annual insect emergence varied from 167.5 – 780.2 mg AFDM m-2 year-1, and constituted ~13% of total benthic production in one site, and this preliminary finding suggests that the water-to-land energy flux attributable to emerging insects along tropical Hong Kong streams is rather minor.
The competition effects of S. hainanensis were studied during the dry season of 2012 and the wet season of 2011 by means of snail inclusion-exclusion manipulations. Snails exerted strong effects on algae and insects during the dry season, but did not significantly affect the structure of benthic assemblages. Algae in shaded streams were more severely depleted by snails, though the reduction in snail densities did not lead to increases in insect abundance or biomass. The effects of snails were not detectable during the wet season, when spate-induced disturbances were more frequent and intense. This generally agreed with the harsh-benign hypothesis, which predicts a reduction in the significance of biotic interactions under more disturbed conditions. Therefore, competition between S. hainanensis and insects was important only at base-flow conditions during the dry season.published_or_final_version
Biological Sciences
Master
Master of Philosophy
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Peoples, Brandon Kevin. "Detection probabilities and local population demographics of fishes in urbanized and forested streams of the New River basin, Virginia." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/31553.
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Aquatic biodiversity continues to decline as humans modify the landscape. A population-level approach is necessary to address the mechanisms of impairment in urban stream habitats. When estimating population-level parameters, incomplete detection of individuals must be accounted for to ensure unbiased estimates. In this thesis, I examined differences in the detection probabilities of stream fishes, and used estimates of size/age-specific detection probabilities to reduce bias in estimates of the reproductive success of various fish species in urban and forested stream habitats. In Chapter 1, I examined differences in detection probabilities of stream fishes among electrofishing passes and size/age groups in the middle New River basin, Virginia. I also examined differences in detection probabilities between two physiographic regions: the middle New River basin, and the upper Wabash River basin, Indiana; and evaluated differences between single- and multiple-season estimation methods. I found that for most species, detection probabilities do not differ among electrofishing passes, size/age classes, between the two regions, or between single- and multiple-season estimation methods. I used size/age-specific estimates of detection probabilities to remove bias from relative abundance estimates of steam fish populations in Chapter 2. In Chapter 2, I examined the reproductive success of six lithophilic and speleophilic fishes in urban and forested reaches of 2nd-4th Strahler-order streams in the middle New River basin. I found that binary classification is a poor method of quantifying reproductive success, that the age distributions of many lithophilic and speleophilic species are dominated by adult individuals in urban habitats, and that the population growth rates of speleophils is reduced in urban habitats. These results suggest that although detection probabilities may be equal among various sources of variation, managers should verify this assumption before assuming equal detectability. The results also suggest that reduced reproductive success of speleophilic and lithophilic species in urban stream habitats may be a mechanism of their impairment.Master of Science
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Berggren, Martin. "Bacterial use of allochthonous organic carbon for respiration and growth in boreal freshwater systems." Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-30051.
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Lindner, Jessica Renee. "Testing nutrient limitation of the benthic biofilm in acid mine drainage remediated streams." Ohio University Honors Tutorial College / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1426336213.
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Yang, Yao, and 楊瑤. "The ecology of a herbivorous fish (Pseudogastromyzon myersi: balitoridae) and its influence on benthic algal dynamics in four HongKong streams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508646.
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Caprile, Jose A. "The geochemical influence of trace element concentrations from marine sedimentary bedrock on freshwater streams in the western Transverse Mountain Ranges." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10134003.
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Government agencies assess the biological integrity of streams and the chemistry of groundwater to monitor anthropogenic impacts on freshwater ecosystems. Some of the impacted streams lack obvious stressors that can be linked to the impacts. In the case of elevated nutrients and ionic concentrations found in impacted stream sites within the Malibu Creek Watershed, research from the Las Virgenes Municipal Water District pointed towards the naturally occurring leachate from the Modelo formation, which contests previous studies suggesting an influence from anthropogenic activity. Differentiating between natural sources of trace element concentrations and point/non-point source contamination could aid in resolving water quality issues since monitoring occurs near anthropogenic development. Water, bedrock, and diatoms were sampled from spring, seep, and stream sites underlain by Tertiary sedimentary bedrock throughout the study area. Multivariate analyses revealed an association of groups driven by salinity along with a correlation between geochemistry and diatom assemblages. Mixing models and radar charts identified potential rock types as sources for analyte concentrations. Sites that were underlain by the Modelo formation presented brackish water conditions and high nutrient concentrations, which potentially influenced the diatom species compositions found at the spring/seep sites as a result of weathering.
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Britton, Kevin John. "Application of a Mass Balance Partitioning Model of Ra-226, Pb-210 and Po-210 to Freshwater Lakes and Streams." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38459.
Full textAbstract:
The objectives of this thesis were: (1) to develop a mass balance partitioning model of the natural uranium-238 series comprising radium-226, lead-210 and polonium-210 and (2) to apply the model to estimate the source and fate of these radionuclides in freshwater lakes and streams. Samples were collected from Ottawa River watershed tributaries and measured for lead-210 and polonium-210 content to determine the water concentrations that were input to the model.
The radium-226 partitioning model was developed by reconstructing and analyzing Quantitative Water, Air, Sediment Interaction (QWASI) models of lead for Lake Ontario and Hamilton Harbour and selecting parameters for an updated QWASI model of lead for a Lake Ontario basin. This study gave insight about model basis definition, and partition coefficient and sediment particle constraint. The radium-226 series model was formulated by connecting separate QWASI modules for radium-226, lead-210 and polonium-210 with decay and ingrowth terms. The radium-226 model was applied to studies of Crystal Lake, Wisconsin; Bickford Pond, Massachusetts; and Clinton River, Michigan, using parameters reported in these and other studies. Model error was evident in the applications to Crystal Lake due to underlying lake heterogeneity, to Bickford Pond due to unidentified sources of lead-210 from sediment diffusion or watershed runoff, and to Clinton River from watershed runoff.
The model was applied to seven Laurentian Shield lakes in the Ottawa River watershed using the sample measurements as the basis for water concentration inputs. The application showed that hydrologic flushing rate may be a factor in the proportion of watershed atmospheric deposition and overall Pb-210 input to the water. Laurentian Shield Lakes with the lowest hydrologic flushing rates (<3 a-1) had proportions of Pb-210 losses to sediment greater than 85%. In another application to Judge Sissons Lake, Nunavut, the model indicated that the watershed was the source of about 85% of Pb-210 and 98% of Po-210 input to the water, and that a significant geologic component of Pb-210 input to the lake was likely. The model indicated that most of the Pb-210 in Judge Sissons Lake was lost to outflow, and that most of the Po-210 was lost to sediment.
The model showed that sedimentation is a better proxy measurement for atmospheric deposition of Pb-210 to the Laurentian lakes than originally estimated. The model also showed that watershed contributions to Judge Sissons Lake could explain the observed background concentrations of Pb-210 and Po-210.
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Perez-Reyes, Omar. "Population and Community Dynamics of Freshwater Decapods in Response to Ecological and Anthropogenic Factors in Subtropical Streams in the Caribbean." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4501.
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Streams have been impacted by human activities in a variety of ways. Over time, these ecosystems become dominated by the most resilient species, with significant losses in the natural components that provide valuable ecosystem services to people. In impacted streams, the loss of ecosystem services often is not recognized until the stream has already been dramatically altered. In this study, I provide data on the natural distribution of freshwater decapods and the status of decapod communities in streams with different land use histories.
I reviewed the decapod distribution for the Caribbean to provide an update of the species that inhabit the freshwater systems. I determined the presence of 18 species of decapods in Puerto Rico and concluded that these decapods follow the island-species relationship in the Caribbean. Also, I present data associated with decapod community dynamics in watersheds with different urban development. As, expected the highly urban watershed had lower diversity and density of decapods than the medium and low urban watersheds. The variations in decapod communities among watersheds correlated with the degradation of the physical-chemical environments and clearing of the riparian zones. I compare the food webs among streams with different human impacts. Specific influences of point/nonpoint sources of N could be distinguished in food web components. This shows to an effect of human activities on the stream and watershed. In addition, I determined the effect of abiotic and biotic factors on the growth of A.lanipes (0.27 mm) and X.elongata (0.1 mm) over the 10-year period of study. The results showed that these species transform a wide range of organic materials into their biomass. Finally, I developed a series of education projects which promote the understanding and knowledge of freshwater ecosystems; interactions and the organisms that inhabit these systems. The results showed an increasing interest about freshwater fauna and ecosystems.
I concluded that: a) the distribution of freshwater decapods in the Caribbean islands follows the area-species relationship; b) urbanization represents one of the many distinct land uses that affect habitat structure, energy sources and biotic interactions; and c) it’s necessary to present the results of our research to the general public in ways that are easily understood.
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Astorga, A. (Anna). "Diversity patterns in marine and freshwater environments:the role of environmental and spatial factors across multiple scales." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514292293.
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Abstract
Recognition of the importance of a regional perspective for understanding the structure and dynamics of local assemblages has stimulated the emergence of the field of macroecology. Most attention has been directed to terrestrial ecosystems, while large-scale patterns in biodiversity of aquatic organisms have received less attention. In this thesis I examined patterns of aquatic diversity across several geographic areas and scales, in an effort to understand some of the environmental and spatial factors determining species diversity in aquatic environments. The main objectives of this thesis were: (i) to examine the latitudinal diversity patterns of marine crustaceans and molluscs and their relationship to large scale environmental gradients, (ii) to study macroinvertebrate species richness in headwater streams at two spatial extents, within and across drainage systems, and assess the relative importance of local, landscape and regional variables, and (iii) to study diversity patterns of macroorganisms vs microorganism, comparing distance decay patterns of stream diatoms, macroinvertebrates and bryophytes.
Latitudinal diversity patterns of crustaceans and molluscs were clearly related to larval developmental mode. An increase in species richness towards high latitudes was found for species with direct development, whereas richness of species with planktotrophic development decreased poleward. Sea surface temperature was the most important environmental gradient related to species richness of both phyla and each developmental mode, but with different effects on each mode.
Stream macroinvertebrate species richness at the bioregion extent was negatively related to water humic content. Another factor related to species richness at the bioregion extent was elevation range, a variable linked to stream topographic heterogeneity. Local environmental variables explained most of the variation in species richness at the drainage system extent, however high among-region variability was evident.
Patterns between macro- and microorganism may not be fundamentally different, but the level of environmental control varied, being strongest for diatoms, while some groups of benthic macroinvertebrates exhibited relatively strong dispersal limitation. The relative importance of niche vs. dispersal processes is not simply a function of organism size but other traits (e.g. life-history type, dispersal capacity) may obscure this relationship.
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Ruffing, Claire Marie. "Influence of legacy disturbance on functional connections between geomorphology and organic matter dynamics in mountain streams." Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18710.
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Doctor of PhilosophyDepartment of Geography
Melinda Daniels
Geomorphic properties of streams are linked to ecosystem function through processes related to storage, transport, and other drivers regulating biogeochemical conditions. Disturbances altering the physical template of a stream are associated with cascading impacts on ecosystem function. However, few disturbances are studied at long time scales and so the legacy of such events and the implications for ecosystem structure and function are not well understood. This research investigates the role of historic tie-driving, a channel disturbance legacy, in shaping present-day stream channel conditions in the Rocky Mountain region and the associated implications for organic matter dynamics. Using a combination of geomorphic and riparian surveys, organic matter and vegetation sampling, and modeling, I show that components of mountain stream ecosystems have recovered from tie-driving at varying rates. First, I addressed how tie-driving has altered channel morphology and wood loading. Tie-driven streams are narrower, shallower, less rough, and have less wood than non-driven reference reaches. In a second study, I focused on differences in carbon storage within the stream and riparian area between tie-driven and non-driven streams. Carbon stored on the landscape represents a long-term component of the terrestrial carbon cycle and some, but not all, components have been impacted by tie-driving. Large instream wood, coarse downed wood, and fine downed wood were identified as carbon storage components that were significantly smaller in tie-driven stream-riparian corridors. Finally, I modeled whole stream ecosystem metabolism and tested whether abiotic drivers influenced variations in rates of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP). Results from this work suggest that rates of GPP were significantly different between tie-driven and non-driven streams and were partially explained by variations in light related to canopy structure. However, variations in ER and NEP were not significantly different between tie-driven and non-driven sites. Taken as a whole, this work shows that ecosystems bear the imprint of historic disturbances but individual ecosystem components recover at differing rates. Additionally, integrating stream hydro-geomorphic and ecological dynamics is an effective approach to understanding the impact of channel disturbances in shaping ecosystem function at a variety of spatial and temporal scales.
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Bergfur, Jenny. "Ecological integrity of boreal streams : assessing impacts on community structure and function /." Uppsala : Dept. of Environmental Assessment, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200750.pdf.
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Aluma, Ebenezer Ejiro. "Mercury Bioaccumulation in Southeast Ohio's Acid Mine Impacted Streams Using the Crayfish (Orconectes sanbornii) as an Indicator Species." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1312853952.
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Bunch, Aubrey R. "Abundance of nonprescription pharmaceuticals in central Indiana streams and effects on sediment microbial activity." Muncie, IN : Ball State University, 2009. http://cardinalscholar.bsu.edu/640.
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Roberto, Alescia. "METAL EFFECTS ON FRESHWATER MICROBIAL COMMUNITY COMPOSITION, STRUCTURE, AND FUNCTION IN AN URBAN STREAM." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1543839535987157.
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Bambakidis, Theodore. "Changes in Benthic Algal Community Structure Following an Unpredictable Stream-Wide Desiccation Event." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1245682807.
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梁士倫 and Sze-lun Leung. "Scale-dependent effects of spatial and temporal variability on benthicmacroinvertebrate communities in Hong Kong streams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31243319.
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Kusi, Joseph, Phillip R. Scheuerman, and Kurt J. Maier. "Antimicrobial Properties of Silver Nanoparticles May Interfere with Fecal Indicator Bacteria Detection in Pathogen Impaired Streams." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etsu-works/7834.
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Silver nanoparticles (AgNPs) are expected to enter aquatic systems, but there are limited data on how they might affect microbial communities in pathogen impaired streams. We examined microbial community responses to citrate-AgNP (10.9 ± 0.7 nm) and polyvinylpyrrolidone (PVP)-AgNP (11.0 ± 0.7 nm) based on microbial concentration and enzyme activity in sediment from a pathogen impaired stream. Addition of each nanoparticle to sediment caused at least a 69% decrease in microbial concentration (1,264 ± 93.6 to 127 ± 29.5 CFU/g) and a 62% decrease in β-glucosidase activity (11.7 ± 2.1 to 1.3 ± 0.3 μg/g/h). Each AgNP reduced alkaline phosphatase activity but their effects were not statistically significant. Sediment exposed to 0.108 mg Ag/kg of AgNO3 resulted in a 92% decrease in microbial concentration and a reduced enzyme activity which was not statistically significant. Measured total silver in sediments treated with AgNPs which exhibited significant inhibition effects on the microbial community ranged from 0.19 ± 0.02 to 0.39 ± 0.13 mg Ag/kg. These concentrations tested in this study are much lower than the expected concentrations (2-14 mg Ag/kg) in freshwater sediments. The results of this study demonstrate that AgNPs can alter microbial community activity and population size, which may lead to false negative fecal indicator bacteria detection and enumeration using methods that rely on β-glucosidase activity. We conclude that the presence of AgNPs in impaired streams and recreational waters can influence pathogen detection methods, potentially affecting public health risk estimates.
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Suurkuukka, H. (Heli). "Spatial and temporal variability of freshwater biodiversity in natural and modified forested landscapes." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526207087.
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Abstract Understanding of natural and human induced changes to freshwater biodiversity patterns is critical for efficiently conserving and managing these highly impacted ecosystems. In this doctoral thesis, I study the natural spatial and temporal variability of littoral macroinvertebrate communities, as well as aquatic biodiversity responses (of bryophytes, macroinvertebrates and diatoms) to human impact on forested headwater streams. I also study the temporal variability of natural and human-impacted stream communities. I show that littoral macroinvertebrate communities are most variable between individual samples and to some extent between littorals, and that the diversity patterns of rare and common littoral macroinvertebrates vary at different spatial scales. Temporal (interannual) variability is of minor importance, particularly for the core species of the community. For rare species, however, the temporal component was generally more important than spatial turnover. For headwater streams, I show that most taxonomic groups responded negatively to human impact on the adjacent riparian forest. Nevertheless, pristine riparian forest is not a sufficient surrogate for stream biodiversity as also streams with relatively disturbed riparian forests supported diverse benthic communities. A rapid classification method based on the physical structure of the stream channel and its riparian forest is able to identify the reference-state communities, as well as the most severely altered communities, but a reliable identification of the intermediately-disturbed sites would need more precise information about the key stressors of stream communities. I found that fine sediments originating from forest drainage were the main factor causing reduction of stream biodiversity. I also found that forestry impacted streams varied temporally more than pristine streams, emphasizing the importance of interannual sampling of impacted streams for a reliable status assessmentTiivistelmä Luonnollisen ja ihmisen aiheuttaman biodiversiteettivaihtelun ymmärtäminen hoito- ja suojelutoimissa on tärkeää pienvesien monimuotoisuuden turvaamiseksi. Tarkastelen väitöskirjassani järvien rantavyöhykkeen pohjaeläinten ajallista ja paikallista vaihtelua sekä latvapurojen eliöyhteisöjen (pohjaeläimet, sammalet, piilevät) vasteita ihmisen aiheuttamaan fysikaaliseen muutokseen rantametsässä ja purouomassa. Tarkastelen myös ajallisen vaihtelun eroja luonnontilaisten ja ihmisvaikutteisten latvapurojen eliöyhteisöjen välillä. Osoitan, että järven rantavyöhykkeen pohjaeläinyhteisöt vaihtelevat eniten yksittäisten näytteiden välillä ja pienessä määrin eri rantojen välillä, mutta ajallinen vaihtelu ei heikennä tulosten luotettavuutta muiden kuin harvinaisten lajien osalta yhteen vuoteen rajoittuvassa näytteenotossa. Purotutkimuksissa osoitan, että useiden vesieliöryhmien lajirunsaus muuttuu ihmisen aiheuttaman rantametsän muutoksen seurauksena, mutta luonnontilaista rantametsää ei silti voida pitää yksiselitteisesti myös puron suojelutason mittarina, koska se ei välttämättä turvaa eliöiden lajistollista eheyttä suhteessa alkuperäiseen alueelliseen lajistoon. Rantametsän ja uoman fysikaalisiin rakennepiirteisiin perustuvaa nopeaa luokittelumenetelmää voidaan käyttää eliöyhteisöltään monimuotoisimpien ja metsätalouden voimakkaimmin rasittamien purojen tunnistamisessa. Eliöyhteisöltään lievemmin muutettujen purojen luotettavaan erotteluun luokittelun pitäisi kuitenkin sisältää tarkempaa tietoa metsäojitusten aiheuttamasta liettymisestä, joka on tulosteni perusteella haitallisin metsätaloudesta johtuva puroyhteisöjä rasittava tekijä. Havaitsin myös metsätalouden rasittamien purojen tilanarvioinnin toistettavuuden olevan luonnontilaisia puroja heikompaa, joten metsätalouden rasittamien purojen pidempiaikainen seuraaminen tuntuu välttämättömältä luotettavien tilanarvioiden tuottamiseksi