Journal articles on the topic 'Index of Stream Condition'
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Yirigui, Lee, and Nejadhashemi. "Multi-Scale Assessment of Relationships between Fragmentation of Riparian Forests and Biological Conditions in Streams." Sustainability 11, no. 18 (September 16, 2019): 5060. http://dx.doi.org/10.3390/su11185060.
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Due to anthropogenic activities within watersheds and riparian areas, stream water quality and ecological communities have been significantly affected by degradation of watershed and stream environments. One critical indicator of anthropogenic activities within watersheds and riparian areas is forest fragmentation, which has been directly linked to poor water quality and ecosystem health in streams. However, the true nature of the relationship between forest fragmentation and stream ecosystem health has not been fully elucidated due to its complex underlying mechanism. The purpose of this study was to examine the relationships of riparian fragmented forest with biological indicators including diatoms, macroinvertebrates, and fish. In addition, we investigated variations in these relationships over multiple riparian scales. Fragmentation metrics, including the number of forest patches (NP), proportion of riparian forest (PLAND), largest riparian forest patch ratio (LPI), and spatial proximity of riparian forest patches (DIVISION), were used to quantify the degree of fragmentation of riparian forests, and the trophic diatom index (TDI), benthic macroinvertebrates index (BMI), and fish assessment index (FAI) were used to represent the biological condition of diatoms, macroinvertebrates, and fish in streams. PLAND and LPI showed positive relationships with TDI, BMI, and FAI, whereas NP and DIVISION were negatively associated with biological indicators at multiple scales. Biological conditions in streams were clearly better when riparian forests were less fragmented. The relationships of NP and PLAND with biological indicators were stronger at a larger riparian scale, whereas relationships of LPI and DIVISION with biological indicators were weaker at a large scale. These results suggest that a much larger spatial range of riparian forests should be considered in forest management and restoration to enhance the biological condition of streams.
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Maloney, Kelly Oliver, Daren Milo Carlisle, Claire Buchanan, Jennifer Lynn Rapp, Samuel Hess Austin, Matthew Joseph Cashman, and John André Young. "Linking Altered Flow Regimes to Biological Condition: an Example Using Benthic Macroinvertebrates in Small Streams of the Chesapeake Bay Watershed." Environmental Management 67, no. 6 (March 12, 2021): 1171–85. http://dx.doi.org/10.1007/s00267-021-01450-5.
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AbstractRegionally scaled assessments of hydrologic alteration for small streams and its effects on freshwater taxa are often inhibited by a low number of stream gages. To overcome this limitation, we paired modeled estimates of hydrologic alteration to a benthic macroinvertebrate index of biotic integrity data for 4522 stream reaches across the Chesapeake Bay watershed. Using separate random-forest models, we predicted flow status (inflated, diminished, or indeterminant) for 12 published hydrologic metrics (HMs) that characterize the main components of flow regimes. We used these models to predict each HM status for each stream reach in the watershed, and linked predictions to macroinvertebrate condition samples collected from streams with drainage areas less than 200 km2. Flow alteration was calculated as the number of HMs with inflated or diminished status and ranged from 0 (no HM inflated or diminished) to 12 (all 12 HMs inflated or diminished). When focused solely on the stream condition and flow-alteration relationship, degraded macroinvertebrate condition was, depending on the number of HMs used, 3.8–4.7 times more likely in a flow-altered site; this likelihood was over twofold higher in the urban-focused dataset (8.7–10.8), and was never significant in the agriculture-focused dataset. Logistic regression analysis using the entire dataset showed for every unit increase in flow-alteration intensity, the odds of a degraded condition increased 3.7%. Our results provide an indication of whether altered streamflow is a possible driver of degraded biological conditions, information that could help managers prioritize management actions and lead to more effective restoration efforts.
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Kakore, Blandina Genes, Md Mamun, Sang-Jae Lee, and Kwang-Guk An. "Land-Use Pattern as a Key Factor Determining the Water Quality, Fish Guilds, and Ecological Health in Lotic Ecosystems of the Asian Monsoon Region." Water 14, no. 17 (September 5, 2022): 2765. http://dx.doi.org/10.3390/w14172765.
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Land-use patterns influence water quality in lotic ecosystems worldwide; consequently, deteriorating water quality affects fish communities and composition and the ecological health of water bodies. This study aimed to evaluate how land use, stream order, and elevation regulate water quality and ecological health in 64 streams based on the following four land cover types: namely, forest, agriculture, urban upstream, and urban downstream regions. Spatial analysis revealed that urban downstream areas had higher nutrient concentrations [total phosphorus (TP) as follows: 117 µg/L; total nitrogen (TN): 5.57 mg/L] and organic pollutants [chemical oxygen demand (COD): 7.71] than other regions. Empirical analysis indicated that TP (R2 = 0.46) had a high relation with chlorophyll-a (Chl-a) compared to TN (R2 = 0.23) and TN:TP (R2 = 0.20). Elevation, stream order, and monsoon season significantly impact nutrients, organic matter, suspended particles, ionic content, and algal chlorophyll concentrations. The index of biotic integrity (IBI) was significantly positively correlated with elevation (R2 = 0.387), indicating that forest streams (high elevation) had better water quality and ecological health than lower-elevation streams. The proportion of insectivore species shows a significant negative relationship with biological oxygen demand (BOD) (R2 = 0.123) and TP (R2 = 0.155). The multi-metric index of biotic integrity (IBI) model suggested that the ecological health of forest streams was in fair condition. In contrast, agricultural streams were in poor condition, and urban upstream and downstream were in very poor conditions. The outcomes of this study indicated that land-use patterns and elevation largely regulate the water quality and ecological health of the streams.
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Collier, Kevin J., and Anthony R. Olsen. "Monitoring network-design influence on assessment of ecological condition in wadeable streams." Marine and Freshwater Research 64, no. 2 (2013): 146. http://dx.doi.org/10.1071/mf12267.
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We investigated outcomes of three monitoring networks for assessing ecological character and condition of wadeable streams, Waikato region, New Zealand. Site selection was based on professional judgment, stratification within categories of watershed characteristics, or on using an unequal-probability survey design. The professional-judgment network, stratified network and all site analyses included more ≥4th-order streams than for the probability-network survey-design estimates Professional-judgment and stratified network sites and survey-design analyses incorporated higher-quality catchments with coarser substrates. Cumulative frequency distributions indicated that the stratified and/or judgmental networks yielded fewer taxa than did the probability network, and that the stratified network provided lower estimates of the macroinvertebrate community index (MCI). Compared with the probability-network survey-design analysis, the stratified network site analysis underestimated percentage stream length classed as ‘Excellent’ by the quantitative MCI, and the professional-judgment site and survey-design analyses overestimated the percentage classed ‘Fair’ by the average score per metric. We conclude that deriving reliable estimates of wadeable stream character and condition requires (1) clearly defining and quantifying the target population for which inferences will be drawn, (2) accounting for probability of site selection and (3) optimising spatial representation across dominant stressor gradients.
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Yirigui, Yirigui, Sang-Woo Lee, A. Pouyan Nejadhashemi, Matthew R. Herman, and Jong-Won Lee. "Relationships between Riparian Forest Fragmentation and Biological Indicators of Streams." Sustainability 11, no. 10 (May 20, 2019): 2870. http://dx.doi.org/10.3390/su11102870.
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Anthropogenic activities, such as land use and land cover modifications in riparian areas, can alter the degree of fragmentation of riparian vegetation, lead to the degradation of stream habitats, and affect biological communities in the streams. The characteristics of the riparian forests can modify the condition of stream environments and the transporting mechanisms of materials, sediments, nutrients, and pollutants loaded from the watersheds. This study aimed to examine the relationships between forest fragmentation and three biological indicators of trophic diatom, benthic macroinvertebrate, and the fish assessment in the Nakdong River, Korea. Eighty-nine biological assessment sampling sites in the National Aquatic Ecological Monitoring Program of South Korea were identified. For each sampling site, riparian forest data within a 500 m radius were extracted from national LULC using GIS to compute fragmentation metrics using FRAGSTATS software. Four fragmentation metrics—number of forest patches, percentage of riparian forest cover (PLAND), largest riparian forest patch index (LPI), and riparian forest division index (DIVISION)—were correlated with the biological indicators. Also, due to severe spatial autocorrelation among observations, the fragmentation metrics and stream environmental variables were regressed to biological indicators using regression tree analysis. Our results indicate that the biological indicators were significantly associated with most forest fragmentation metrics. We found positive correlations of PLAND and LPI with biological indicators, whereas DIVISION was negatively correlated with biological indicators. Both correlation and regression tree analyses revealed that the biological conditions of streams were likely to be better if riparian forests are less fragmented. Particularly, stronger relationships were revealed between macroinvertebrates and fish with the fragmentation metrics of riparian forests than with benthic diatoms. However, these relationships varied with elevation, stream size, and slope conditions. The results of this study reinforced the importance of including riparian forests in the planning, restoration, and management of stream environments. These results also suggested that planners and managers may need to consider different strategies for different stream environments and topographic characteristics in managing riparian forests.
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Donatich, Sara, Barbara Doll, Jonathan Page, and Natalie Nelson. "Can the Stream Quantification Tool (SQT) Protocol Predict the Biotic Condition of Streams in the Southeast Piedmont (USA)?" Water 12, no. 5 (May 22, 2020): 1485. http://dx.doi.org/10.3390/w12051485.
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In some states, the Stream Quantification Tool (SQT) has been adopted to quantify functional change of stream mitigation efforts. However, the ability of the SQT protocol to predict biological function and uphold the premise of the Stream Functions Pyramid (Pyramid) remains untested. Macroinvertebrate community metrics in 34 headwater streams in Piedmont, North Carolina (NC, USA) were related to NC SQT protocol (version 3.0) factors and other variables relevant to ecological function. Three statistical models, including stepwise, lasso, and ridge regression were used to predict the NC Biotic Index (NCBI) and Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness using two datasets: 21 SQT variables and the SQT variables plus 13 additional watershed, hydraulic, geomorphic, and physicochemical variables. Cross-validation revealed that stepwise and ridge outperformed lasso, and that the SQT variables can reasonably predict biology metrics (R2 0.53–0.64). Additional variables improved prediction (R2 0.70–0.88), suggesting that the SQT protocol is lacking metrics important to macroinvertebrates. Results moderately support the Pyramid: highly predictive ridge models included metrics from all levels, while highly predictive stepwise models included metrics from higher levels, and not watershed hydrology. Reach-scale metrics were more important than watershed hydrology, providing encouragement for projects limited by watershed condition.
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Myers, Thomas J., and Sherman Swanson. "AQUATIC HABITAT CONDITION INDEX, STREAM TYPE, AND LWESTOCK BANK DAMAGE IN NORTHERN NEVADA." Journal of the American Water Resources Association 27, no. 4 (August 1991): 667–77. http://dx.doi.org/10.1111/j.1752-1688.1991.tb01468.x.
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Urdánigo, Juan, Karla Pérez, Elian Intriago, Gabriela Arriaga, Solange Zambrano, and Oscar Prieto. "Bioindicators of water quality with different riparian cover in the Guapara micro watershed, Ecuador." Revista de la Facultad de Agronomía, Universidad del Zulia 39, no. 4 (November 24, 2022): e223952. http://dx.doi.org/10.47280/revfacagron(luz).v39.n4.07.
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Agricultural activities produce changes in the margins of the stream banks, causing disturbances in water quality, and in the assemblage of aquatic insect communities. The objective of this research is to evaluate the changes in the structure and composition of the aquatic macroinvertebrate community, and physicochemical variables in relation to the land use of the Guapara river, Cotopaxi province, Ecuador. Samplings were conducted during the rainy season (December to February 2018-2019) in three streams with different riparian cover: agricultural, native forest, and forest plantations, where samples of aquatic insects and physicochemical parameters were collected in situ. A total of 461 aquatic insects corresponding to 7 orders and 25 families were collected. In general, the highest abundance in order and family was presented by Ephemeroptera with 34 %, and Leptophlebiidae with 21 % respectively. According to the Ephemeroptera, Plecoptera Trichoptera (EPT) index, the highest ecological condition was found in streams with native forest cover, and forest plantations respectively, and decreased in the stream with agricultural cover; while BMWP-Cr indicated water contamination in the three streams. Hydrobiosidae (Trichoptera) were associated with high turbidity values; while Gerridae (Hemiptera) were associated with high dissolved oxygen concentrations; in addition, Ptilodactylidae (Coleoptera) preferred the Q1-CA, and Q3-CF conditions, while Leptophlebiidae (Ephemeroptera) were associated with the stream of native forest. A negative influence of agricultural activity on the physicochemical parameters of the water and on the structure of the aquatic insect community assemblage was evidenced.
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Wu, J. Y., J. R. Thompson, R. K. Kolka, K. J. Franz, and T. W. Stewart. "Using the Storm Water Management Model to predict urban headwater stream hydrological response to climate and land cover change." Hydrology and Earth System Sciences 17, no. 12 (December 3, 2013): 4743–58. http://dx.doi.org/10.5194/hess-17-4743-2013.
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Abstract. Streams are natural features in urban landscapes that can provide ecosystem services for urban residents. However, urban streams are under increasing pressure caused by multiple anthropogenic impacts, including increases in human population and associated impervious surface area, and accelerated climate change. The ability to anticipate these changes and better understand their effects on streams is important for developing and implementing strategies to mitigate potentially negative effects. In this study, stream flow was monitored during April–November (2011 and 2012), and the data were used to apply the Storm Water Management Model (SWMM) for five urban watersheds in central Iowa, USA, representing a gradient of percent impervious surface (IS, ranging from 5.3 to 37.1%). A set of three scenarios was designed to quantify hydrological responses to independent and combined effects of climate change (18% increase in precipitation), and land cover change (absolute increases between 5.2 and 17.1%, based on separate projections of impervious surfaces for the five watersheds) for the year 2040 compared to a current condition simulation. An additional set of three scenarios examined stream response to different distributions of land cover change within a single watershed. Hydrological responses were quantified using three indices: unit-area peak discharge, flashiness (R-B Index; Richards–Baker Index), and runoff ratio. Stream hydrology was strongly affected by watershed percent IS. For the current condition simulation, values for all three indices were five to seven times greater in the most developed watershed compared to the least developed watershed. The climate change scenario caused a 20.8% increase in unit-area peak discharge on average across the five watersheds compared to the current condition simulation. The land cover change scenario resulted in large increases for all three indices: 49.5% for unit-area peak discharge, 39.3% for R-B Index, and 73.9% for runoff ratio, on average, for the five watersheds. The combined climate and land cover change scenario resulted in slight increases on average for R-B Index (43.7%) and runoff ratio (74.5%) compared to the land cover change scenario, and a substantial increase, on average, in unit area peak discharge (80.1%). The scenarios for different distributions of land cover change within one watershed resulted in changes for all three indices, with an 18.4% increase in unit-area peak discharge for the midstream scenario, and 17.5% (downstream) and 18.1% (midstream) increases in R-B Index, indicating sensitivity to the location of potential additions of IS within a watershed. Given the likelihood of increased precipitation in the future, land use planning and policy tools that limit expansion of impervious surfaces (e.g. by substituting pervious surfaces) or mitigate against their impacts (e.g. by installing bioswales) could be used to minimize negative effects on streams.
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Henriques-Oliveira, Ana Lucia, Jorge Luiz Nessimian, and Darcílio Fernandes Baptista. "Diversity and composition of Trichoptera (Insecta) larvae assemblages in streams with different environmental conditions at Serra da Bocaina, Southeastern Brazil." Acta Limnologica Brasiliensia 27, no. 4 (December 2015): 394–410. http://dx.doi.org/10.1590/s2179-975x3215.
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Abstract: Aim The goal of this study is to examine the composition and richness of caddisfly assemblages in streams at the Serra da Bocaina Mountains, Southeastern Brazil, and to identify the main environmental variables, affecting caddisfly assemblages at the streams with different conditions of land use. Methods The sampling was conducted in 19 streams during September and October 2007. All sites were characterized physiographically by application of environmental assessment protocol to Atlantic Forest streams and by some physical and chemical parameters. Of the 19 streams sampled, six were classified as reference, six streams as intermediate (moderate anthropic impact) and seven streams as poor (strong anthropic impact). In each site, a multi-habitat sampling was taken with a kick sampler net. The sample was composed by 20 units, each one corresponded to 1 m2 of collected substrate, corresponding 20 m2 of sampling area. The material was placed in a plastic container (500 µm of mesh), washed, homogenized and sub-sampled. For each stream, 6 subsamples were randomly sorted. Results Were collected 2,113 caddisfly larvae, belonging to 12 families and 28 genera. Hydropsychidae and Leptoceridae were the most abundant families, and Smicridea was the most abundant genus. Sorensen’s index results showed that the streams studied were grouped according to environmental integrity. The Indicator Species Analysis showed only characteristic taxa to reference streams. Canonical Correspondence Analysis showed that caddisfly assemblage was strongly influenced by nitrate concentration, pH and condition of riparian vegetation. Multiple regression analysis indicated significant correlations to five genera with some environmental parameters, besides total abundance of Trichoptera. Conclusions Ours results showed that degree of environmental impact, mainly the nitrate concentration, pH, and condition of cover vegetation acted as a major factor in determining the Trichoptera assemblages present in the stream of the Serra da Bocaina, separating streams along an environmental gradient.
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Edegbene, Augustine Ovie, Frank Chukwuzuoke Akamagwuna, Oghenekaro Nelson Odume, Francis Ofurum Arimoro, Tega Treasure Edegbene Ovie, Ehi Constantine Akumabor, Efe Ogidiaka, Edike Adewumi Kaine, and Kehi Harry Nwaka. "A Macroinvertebrate-Based Multimetric Index for Assessing Ecological Condition of Forested Stream Sites Draining Nigerian Urbanizing Landscapes." Sustainability 14, no. 18 (September 8, 2022): 11289. http://dx.doi.org/10.3390/su141811289.
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Urban pollution is increasing at an alarming rate within the catchments of forested riverine systems in sub-Saharan Africa, Nigeria inclusive. Assessing the impact of pollution in riverine systems in the Niger Delta region is still within the use of physico-chemical variables and biota-based assemblage. In covering this important gap in freshwater biomonitoring, we developed a macroinvertebrate-based multimetric index (MMI) that would be useful in monitoring, assessing, and managing forested riverine sites affected by urban pollution. We collected macroinvertebrates and physico-chemical samples monthly at 20 sites in 11 streams. Physico-chemical variables were analysed using standard methods while a kick sampling procedure was employed in collecting macroinvertebrates. The physico-chemical variables were used to classify the sites into three disturbance categories: least-impacted sites (LIS), moderately impacted sites (MIS), and heavily impacted sites (HIS). Fifty-nine candidate macroinvertebrate metrics were selected and screened for developing our MMI. We employed sensitivity, seasonality, repeatability and redundancy tests, and metric scoring in screening and arriving at the final metrics for the MMI development. Five metrics were finally selected for the MMI development: Trichoptera abundance, %Chironomidae+Oligochaeta, Coleoptera richness, Simpson diversity, and Shannon–Wiener index. Correlation in the selected metrics with physico-chemical variables showed that Simpson diversity was negatively correlated with pH in the MIS and Coleoptera richness was positively correlated with dissolved oxygen (DO) and water depth in the LIS. Nitrate, biochemical oxygen demand (BOD), conductivity, and water temperature were negatively correlated with %Chironomidae+Oligochaeta in the HIS. This MMI can aid river and stream managers in assessing the ecological conditions of rivers and streams in the Niger Delta region of Nigeria.
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Ladson, Anthony R., Lindsay J. White, Jane A. Doolan, Brian L. Finlayson, Barry T. Hart, P. Sam Lake, and John W. Tilleard. "Development and testing of an Index of Stream Condition for waterway management in Australia." Freshwater Biology 41, no. 2 (March 1999): 453–68. http://dx.doi.org/10.1046/j.1365-2427.1999.00442.x.
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Borek, Łukasz, and Tomasz Kowalik. "Hydromorphological Inventory and Evaluation of the Upland Stream: Case Study of a Small Ungauged Catchment in Western Carpathians, Poland." Land 11, no. 1 (January 17, 2022): 141. http://dx.doi.org/10.3390/land11010141.
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The hydromorphological conditions of watercourses depend on numerous natural and anthropogenic factors such as buffer zones or human infrastructure near their banks. We hypothesised that, even in a small stream, there can be substantial differences in the hydromorphological forms associated with naturalness and human impact. The paper aims at the field inventory and evaluation of the hydromorphological conditions of a small upland stream in the conditions of contemporary human activity, against the background of meteorological and hydrological conditions. The study concerned a left-bank tributary of the Stradomka River located in the Wiśnicz Foothills (Western Carpathians). The analyses were conducted with the use of the Polish method, the Hydromorphological Index for Rivers (HIR), which conforms to the EU Water Framework Directive (WFD). The hydromorphological condition and quality of habitats were evaluated based on the Hydromorphological Diversity Score (HDS) and Habitat Modification Score (HMS). The study shows that the largest changes in stream hydomorphology and habitat conditions took place in the downstream, urbanised stream catchment area with an intensive development of construction and technical infrastructure. The hydromorphological condition of the examined stream sections was evaluated as good or poor. The best hydromorphological conditions were found in the section located in the semi-natural area, and the worst in the urbanised area. As our research shows, the strong influence of human activity, including weather extremes, and the risks and hydrological hazards of the hydromorphological conditions of the small, ungauged catchment, highlight the necessity to search for other research methods to support the decision-making cycle in the transformation of riverbeds and catchments.
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Wu, J. Y., J. R. Thompson, R. K. Kolka, K. J. Franz, and T. W. Stewart. "Using the Storm Water Management Model to predict urban headwater stream hydrological response to climate and land cover change." Hydrology and Earth System Sciences Discussions 10, no. 6 (June 4, 2013): 7091–126. http://dx.doi.org/10.5194/hessd-10-7091-2013.
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Abstract. Streams are natural features in urban landscapes that can provide ecosystem services for urban residents. However, urban streams are under increasing pressure caused by multiple anthropogenic impacts, including increases in human population and associated impervious surface area, and accelerated climate change. The ability to anticipate these changes and better understand their effects on streams is important for developing and implementing strategies to mitigate potentially negative effects. In this study, stream flow was monitored during April–November (2011 and 2012), and the data were used to apply the Storm Water Management Model (SWMM) for five urban watersheds in central Iowa, USA representing a gradient of percent impervious surface (IS, ranging from 5.3 to 37.1%). A set of three scenarios was designed to quantify hydrological responses to independent and combined effects of climate change (18% increase in precipitation), and land cover change (absolute increases between 5.2 and 17.1%, based on separate projections of impervious surfaces for the five watersheds) for the year 2040 compared to a current condition simulation. An additional set of three scenarios examined stream response to different distributions of land cover change within a single watershed. Hydrological responses were quantified using three indices: unit-area peak discharge, flashiness (R-B Index), and runoff ratio. Stream hydrology was strongly affected by watershed percent IS. For the current condition simulation, values for all three indices were five to seven times greater in the most developed watershed compared to the least developed watershed. The climate change scenario caused a 20.8% increase in unit-area peak discharge on average across the five watersheds compared to the current condition simulation. The land cover change scenario resulted in large increases for all three indices: 49.5% for unit-area peak discharge, 39.3% for R-B Index, and 73.9% for runoff ratio, on average, for the five watersheds. The combined climate and land cover change scenario resulted in even greater increases for all three indices: 80.1% for unit-area peak discharge, 43.7% for R-B Index, and 74.5% for runoff ratio, on average, for the five watersheds. The scenarios for different distributions of land cover change within one watershed resulted in changes for all three indices, with an 18.4% increase in unit-area peak discharge for the midstream scenario, and 17.5% (downstream) and 18.1% (midstream) increases in R-B Index, indicating sensitivity to the location of potential additions of IS within a watershed. Given the likelihood of increased precipitation in the future, land use planning and policy tools that limit expansion of impervious surfaces (e.g. by substituting pervious surfaces) or mitigate against their impacts (e.g. by installing bioswales) could be used to minimize negative effects on streams.
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Springe, Gunta, Laura Grinberga, and Agrita Briede. "Role of hydrological and hydromorphological factors in ecological quality of medium-sized lowland streams." Hydrology Research 41, no. 3-4 (April 1, 2010): 330–37. http://dx.doi.org/10.2166/nh.2010.119.
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The development of biological communities is an important research issue regarding biological quality elements. However, it is still uncertain how different organism groups and their metrics are affected by different environmental factors. A study of high-quality sites of medium-sized lowland streams typical for Latvia (ecoregion Baltic province) was carried out with an emphasis on hydrological and hydromorphological characteristics. The investigations were carried out within the STAR project using the project designated standard methods. We found that the level of saprobity according to benthic macroinvertebrates was mainly linked with substrate type and stream depth. The trophic diatom index for diatoms on a soft substratum had a negative correlation with altitude and a positive correlation with distance from the source and also stream depth. There were no significant correlations between macrophyte trophic indices and environmental factors associated with stream hydrological conditions. The European fish index was influenced mainly by stream width and distance from the source, which agrees with the results of other researchers. In general, a direct or indirect role of hydrological and hydromorphological factors was evident in the forming of communities characterizing stream ecological quality.
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Kounthongbang, Aloun, Oulaytham Lasasimma, Pany Souliyamath, Keiichiro Iguchi, and Sayaka Ito. "Life history characteristics of the fluvial shrimp Macrobrachium yui (Holthuis, 1950) (Decapoda, Palaemonidae) spawning in the cave streams in northern Laos." Crustaceana 88, no. 2 (2015): 164–83. http://dx.doi.org/10.1163/15685403-00003404.
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This study aims to understand the reproductive and larval characteristics and the migratory patterns of the shrimpMacrobrachium yui(Holthuis, 1950). We conducted monthly samplings of the adult, juvenile and larval shrimp at fixed points in the Xuang River system in northern Laos. We determined the seasonal changes in size frequency distribution, difference in size among sampling sites, occurrence of drifting larvae, and physiological condition of the shrimp. The size distributions ofM. yuidiffered significantly throughout the year among sections of the river system: small-sized juveniles occurred in the Xuang River, various size classes in the Pho Stream, and larger adults in the Bokengsakang cave stream. The gonadosomatic index of females is the highest in the Bokengsakang cave stream and the gonadosomatic index of males is the highest in the Pho Stream. Drifting larvae that had already completed morphological development for settlement on the substrate occurred only in the Bokengsakang cave stream, although the hatched larvae have a free-swimming larval period. The overall results indicate thatM. yuifemales spawn in the Bokengsakang cave stream after mating with males during or before migration to the cave stream, and the hatched larvae remain in the cave stream until settling on the bottom. The life history migration ofM. yuiis attributed to the early stages of the life cycle, depending strongly on the cave stream.
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Golski, Janusz, Jan Mazurkiewicz, Wojciech Andrzejewski, Antoni Przybył, and Jerzy Kozak. "Survival and growth rates of juvenile salmonids reared in lowland streams." Archives of Polish Fisheries 24, no. 4 (December 1, 2016): 187–200. http://dx.doi.org/10.1515/aopf-2016-0016.
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Abstract The aim of this study was to assess the efficiency of propagating juvenile trout, Salmo trutta L. in small lowland streams and to evaluate the impact of the environmental conditions in the streams on the juvenile fish. Brown trout (Salmo trutta fario) and sea trout (Salmo trutta trutta) early fry fed under controlled conditions were used to stock third-order lowland streams. During summer, fall, and spring catches, fry were counted, measured, and weighed. The following parameters were calculated using the data collected: fry stocking density (ind. m-2); survival; specific mortality rate (SMR); length range; mean specimen length; body weight; mean body weight; specific growth rate (SGR); body condition (Fulton’s index). The ichthyological studies were accompanied by simultaneous analyses of environmental conditions that were performed monthly, and benthic macroinvertebrates were sampled in spring and fall. No differences were observed in the biological parameters analyzed between sea trout and brown trout. Variability in environmental parameters such as temperature, oxygenation, conductivity, and stream width and depth were associated with differentiation in the biological parameters of the fry. The results clearly indicate that the considerable potential of small lowland streams for the propagation of salmonid juvenile stages is currently underexploited.
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Yoshida, Claudia Eiko, and Ana Paula Pozzo Rios Rolla. "Ecological attributes of the benthic community and indices of water quality in urban, rural and preserved environments." Acta Limnologica Brasiliensia 24, no. 3 (November 22, 2012): 235–43. http://dx.doi.org/10.1590/s2179-975x2012005000041.
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INTRODUCTION: Reference streams are pristine streams, untouched or unaltered by man, it being possible to use their environmental characteristics as quality threshold values. Besides the organic impacts measured via water quality biological monitoring programs, it has become necessary to evaluate the relationship between alterations in the landscape of streams and surrounding areas and changes in the structure of the macroinvertebrate community; AIM: The objective of the present study was to correlate the changes in the landscape with the ecological attributes of the community and indices of water quality, and to recommend reference condition values for the integrity of streams in the region of Jundiai (SP); METHODS: The benthic fauna were sampled in three urban streams, three rural streams and three preserved streams during July 2010, using a Surber-type sampler. The characteristics of the landscape were evaluated by means of Diversity of Habitat; the community, analyzed for several biodiversity indices, and; the water quality assessed using the indices River-BCI, BMWP-CETEC (CETEC - Science and Technology Center), ASPT and SOMI (SOMI - Serra dos Órgãos Multimetric Index (Serra dos Órgãos is a mountain range national park in the state of Rio de Janeiro)); RESULTS: The structure and the composition of the communities varied according to the stream and this was reflected in the values of the biological and environmental quality indices. The best conditions were found in preserved streams, intermediate streams and rural streams while the worst conditions were found in the urban streams. The significant Pearson correlations (r > 0.73 and P < 0.05) between the diversity of habitat index and the ecological and water quality index attributes in the streams of Jundiai demonstrated that diversity of habitat may be a good predictor of the environmental characteristics evaluated.
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Borowska-Pakuła, Joanna, and Katarzyna Mięsiak-Wójcik. "Assessing discharge periodicity in mountain catchments using classified environmental conditions (Tatra Mountains, Poland)." Journal of Mountain Science 19, no. 1 (December 27, 2021): 16–32. http://dx.doi.org/10.1007/s11629-021-6736-0.
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AbstractThe periodicity of a river expressed in cycles of various lengths (monthly, seasonal, multiannual) is a result of climatic factors and overlapping environmental conditions within its catchment. In uncontrolled or poorly surveyed catchments, it is very difficult to determine the duration of a stream’s hydrological activity. This is especially relevant for catchments with complicated water circulation in karstic rocks. The present study concerns the small catchment of the Strążyski Potok river located in the area of the Tatra National Park, in the Western Tatras. The observation period covered the 2015 hydrological year, which differed hydrologically from average conditions. This study aims to develop a simple method to explain the processes shaping the mountain stream discharge periodicity. The research employed periodic field observations linked with climatic and non-climatic factors. Environmental conditions were assessed as four classes reflecting their influence on appearance or disappearance of mountain stream water. Class boundaries were the values of quartiles. The degree of correspondence between environmental factors and stream field observations was described via the Index DC (Degree Correspondence Index) approach. Complete correspondence (Index DC =0) was found in 23% catchments, a weak relationship between conditions favouring discharge and actual condition (Index DC= -1, +1) was noted within 11 catchments, while in 9 catchments, no such relationship was found (Index DC = -2, +2). The obtained results indicate a correspondence or lack thereof between the environmental potential of the catchment and its discharge periodicity. The discrepancies between the assessment of the influence of climatic and non-climatic factors and the data collected during field observations provide a basis for more detailed studies. Continuation of these studies based on the proposed classifications will allow for a more complete explanation of water disappearance in river channels and the determination of their short- and long-term discharge periodicity.
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Maneechan, Witwisitpong, and Taeng On Prommi. "Diversity and Distribution of Aquatic Insects in Streams of the Mae Klong Watershed, Western Thailand." Psyche: A Journal of Entomology 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/912451.
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The distribution and diversity of aquatic insects and water quality variables were studied among three streams of the Mae Klong Watershed. In each stream, two sites were sampled. Aquatic insects and water quality variables were randomly sampled seven times in February, May, September, and December 2010 and in January, April, and May 2011. Overall, 11,153 individuals belonging to 64 families and nine orders were examined. Among the aquatic insects collected from the three streams, the order Trichoptera was most diverse in number of individuals, followed by Ephemeroptera, Hemiptera, Odonata, Coleoptera, Diptera, Plecoptera, Megaloptera, and Lepidoptera. The highest Shannon index of diversity of 2.934 and 3.2 was recorded in Huai Kayeng stream and the lowest was in Huai Pakkok stream (2.68 and 2.62). The high diversity of insect fauna in streams is an indication of larger microhabitat diversity and better water quality conditions prevailing in the streams. The evenness value was recorded as high in most sites. The high species diversity and evenness in almost all sites indicated good water quality.
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Kim, Jung-Jae, Usman Atique, and Kwang-Guk An. "Long-Term Ecological Health Assessment of a Restored Urban Stream Based on Chemical Water Quality, Physical Habitat Conditions and Biological Integrity." Water 11, no. 1 (January 10, 2019): 114. http://dx.doi.org/10.3390/w11010114.
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We studied the chemical water quality, physical habitat and biotic integrity of an urban stream subjected to restoration measures in South Korea. We used the water pollution index (WPI), qualitative habitat evaluation index (QHEI) and index of biotic integrity (IBI) on the water quality, physical habitat and fish assemblage data respectively, during 2007–2016 in Gap Stream to evaluate the ecological health before and after restoration measures. The results revealed annual mean total phosphorus (TP) dramatically decreased by 13-fold for 10 years and the values of biological oxygen demand (BOD) and chemical oxygen demand (COD) also decreased by >50% over the time, indicating decrease in nutrient enrichment and organic matter pollution after restoration measures. In the meantime, biological health analyses using IBI indicated no major transformation in fish assemblages under restoration impact. However, the proportion of sensitive species increased, and tolerant species decreased after restoration. Gap stream is home to 50 distinct fish species. QHEI proposed that the physical habitat health was in ‘good’ condition during the study period. WPI showed the chemical water quality status remained ‘poor’ during and before restoration but improved to ‘fair-good’ condition in the ensuing years after restoration. The IBI results, however, indicated ‘very poor-poor’ biotic integrity irrespective of restoration measures. CHL-a and TP showed strong (r < 0.7) to moderately strong (r = 0.5–0.7) correlation with significantly important water quality factors. Spatially significant pattern change in TN and TP was obvious as measured levels were significantly higher (p < 0.01) in downstream than upstream. Principal component analysis successfully indicated the placement of water quality factors and indices used as in three distinct stream compartments. The higher pollutant levels in the downstream mainly linked to the nutrient-rich effluents from emerging from the wastewater treatment plants (WWTPs) and industrial complexes operative in the stream catchment. Overall, restoration measures indicated minor impact on fish assemblages and physical habitat due to slow and steady improvement, however, water quality improved due to a decline of nutrients and chemicals downstream. This indicated a positive tendency of improvements in physical habitat and richness of fish assemblages in Gap Stream.
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Merza, Taghreed Reyadh, and Mohammed Abbas Al-Jumaili. "A Review of Studying the Relationship of Traffic Stream Characteristics and Noise Intensity with Flexible Pavement Surface Condition." IOP Conference Series: Earth and Environmental Science 961, no. 1 (January 1, 2022): 012086. http://dx.doi.org/10.1088/1755-1315/961/1/012086.
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Abstract In general, roads are a very important infrastructure to facilitate people’s access to their social and economic activities, so knowing the things that affect the efficiency of these roads is very important and how to maintain them. One of the aims of this research is to shed light on previous studies that showed the relationship between traffic characteristics and noise intensity on the condition of the breakable Pavement. The results of previous studies show that flexible Pavement has 19 potential failures and how to address them. There is a relationship between the characteristics of traffic flow and failures that occur in flexible paving. It is also possible to calculate the road condition by knowing the types of faults on the road using several roads or by using specific formulas to calculate the road condition index. There are relationships between the road condition index, the vehicles’ speed, and the models that link Noise to speed. And that most of the relationships that were used to calculate the elastic pavement condition index and its relationship to the movement characteristics are statistical relationships using ANOVA, recreation, and R2
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Guimarães, Felipe Vieira, Luisa Maria Sarmento-Soares, Ronaldo Fernando Martins-Pinheiro, and Luiz Fernando Duboc. "ASSESSMENT OF STREAM ENVIRONMENTAL CONDITION USING FISHBASED METRICS IN A PROTECTED AREA AND ITS DISTURBED BUFFER ZONE, NORTHEASTERN ATLANTIC RAINFOREST." Oecologia Australis 26, no. 03 (September 15, 2022): 461–75. http://dx.doi.org/10.4257/oeco.2022.2603.05.
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The susceptibility of streams to anthropogenic interference raises the need for continuous assessment of their environmental condition. From early studies to recent approaches, metrics derived from fish assemblages have proven to be fundamental tools in evaluating the ecological condition of watercourses. We assessed the environmental degradation of streams inside and surrounding the Córrego Grande Biological Reserve, state of Espírito Santo, Brazil, to develop and apply a biotic index for this region based on fish metrics. We performed samplings in 19 stream sites along 2012, 2018 and 2019, and collected 24 species belonging to five orders, 11 families, and 21 genera. The sites were classified as least-disturbed (N = 9, all within the protected area), intermediate (N = 8), and most-disturbed (N = 2). Ordination analyses distinctly separated the sites according to their disturbance classes, revealing that the percentage of native vegetation cover in 100 m buffers and type of riparian vegetation played an important role in the environmental quality of these sites. From the initial 38 metrics, three were able to distinguish between disturbance classes: percentage of Siluriformes and Characiformes species, percentage of nektonic species, and percentage of omnivorous individuals. Our results show that these metrics are significant factors to be considered in monitoring the environmental degradation of Atlantic Forest streams.
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Cardoso, Vinicius de Carvalho, and Katharina Eichbaum Esteves. "Life-History traits of Hollandichthys multifascitus (Eigenmann & Norris, 1900) (Characiformes: Characidae) in coastal Atlantic Forest blackwater streams from Southeastern Brazil." Papéis Avulsos de Zoologia 62 (March 10, 2022): e202262016. http://dx.doi.org/10.11606/1807-0205/2022.62.016.
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Ecological and life history traits have been used to understand the basic ecology of fishes. This study aimed to examine the existence of plasticity in life history traits of populations of Hollandichthys multifasciatus in ten blackwater streams. This is an inseminating Characidae, endemic to the Atlantic coastal drainages of Brazil. Different aspects of the life-history of the species, such as mean length, sex ratio, absolute and relative fecundity, gonadosomatic index, condition factor, length-weight relationship and the growth parameter (b) of 185 specimens were studied during the period of low precipitation (June-September). Fish samples were obtained along a 100 m stretch of each stream, and some habitat variables recorded. ANOVA and Kruskal-Wallis tests indicated a similarity in most of the analyzed traits, with exception of the mean length of immatures, Gonadosomatic Index of mature males and condition factor of immatures and mature adults. Also, slope tests of the length-weight relationship were significantly different for immatures. The observed differences were attributed to heterogeneity in food availability and/or other site-specific factors, which may influence growth and/or breeding aspects among the studied localities. The approach used herein may improve understanding of trait plasticity under natural conditions, helping to understand fish-community responses to anthropogenic changes.
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Nyanti, Lee, Nur Ezaimah Idris, Hafida Bolhen, Jongkar Grinang, Teck Yee Ling, Siong-Fong Sim, Chen-Lin Soo, Tonny Ganyai, and Karen Lee Suan Ping. "Fish Assemblages, Growth Pattern and Environmental Factors in Upper Baleh River, Kapit, Sarawak." Borneo Journal of Resource Science and Technology 9, no. 1 (June 26, 2019): 14–25. http://dx.doi.org/10.33736/bjrst.1581.2019.
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A survey of the freshwater fish composition in the upper Baleh River, Sarawak was conducted in 2015. A total of 1,538 specimens, comprising 45 species from nine families were collected using electrofishing devices and cast nets. The family Cyprinidae was the most dominant (62.9%) as well as diverse (42.2%) family, followed by the Balitoridae (31.0%; 31.1%) in the river. The three most dominant species were Tor tambra (18.1%), Lobocheilos ovalis (12.9%), and Parhomaloptera microstoma (11.3%). Shannon’s diversity index, Margalef’s richness index, and Pielou’s evenness index were 2.9, 6.0, and 0.8, respectively, an indication of moderate species diversity. Canonical Correspondence Analysis demonstrate that elevation, stream order and sedimentation were the most significant factors related to fish assemblages in the river, particularly for members of the families Cyprinidae and Balitoridae. The coefficient ‘n’ value in length-weight relationship for T. tambra, L. ovalis, and P. microstoma were determined as 2.92, 2.72, and 3.15, respectively. T. tambra and L. ovalis exhibited a negative allometric growth pattern which could be due to food competition whereas P. microstoma exhibited a positive allometric growth pattern as mountainous forest stream habitat offers favourable environmental conditions. The Fulton’s condition factor of each species indicates that T. tambra and L. ovalis were in poor condition, whereas P. microstoma was in extremely poor condition. It is hypothesized that environmental degradation caused by logging activities have affected the health of the most dominant fish species in the upper Baleh River. Further study should be conducted to determine the underlying factors that are affecting the fish diversity.
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Bourque, C. P. A., and J. H. Pomeroy. "Effects of forest harvesting on summer stream temperatures in New Brunswick, Canada: an inter-catchment, multiple-year comparison." Hydrology and Earth System Sciences 5, no. 4 (December 31, 2001): 599–614. http://dx.doi.org/10.5194/hess-5-599-2001.
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Abstract. This paper presents a pre- and post-harvest comparison of stream temperatures collected in five neighbouring streams (sub-catchments) over a period of five years (1994-1998). The aim of the study was to determine whether land cover changes from clear cutting in areas outside forest buffer zones (applied to streams >0.5 m wide) might contribute to an increase in summer mean stream temperatures in buffered streams downslope by infusion of warmed surface and sub-surface water into the streams. Specific relationships were observed in all five forest streams investigated. To assist in the analysis, several spatially-relevant variables, such as land cover change, mid-summer potential solar radiation, flow accumulation, stream location and slope of the land were determined, in part, from existing aerial photographs, GIS-archived forest inventory data and a digital terrain model of the study area. Spatial calculations of insolation levels for July 15th were used as an index of mid-summer solar heating across sub-catchments. Analysis indicated that prior to the 1995 harvest, differences in stream temperature could be attributed to (i) topographic position and catchment-to-sun orientation, (ii) the level of cutting that occurred in the upper catchment prior to the start of the study, and (iii) the average slope within harvested areas. Compared to the pre-harvest mean stream temperatures in 1994, mean temperatures in the three streams downslope from the 1995 harvest areas increased by 0.3 to 0.7°C (representing a 4-8% increase; p-value of normalised temperatures <<0.05). The greatest temperature change occurred in the stream that had the greatest proportion of its upper catchment harvested (16.8%), which also had the highest calculated potential solar loading ( ~2749 MJ per stream cell). From the analysis it was determined that the thinning applied to the forest buffer of that stream, with a basal area removal of ~28%, was insufficient to cause significant change in the observed stream temperature. Similar effects were observed following a second harvest in 1997. In general, increases in mean stream temperature coincided with forest harvesting activities outside forest buffers, where conditions promoting stream warming were greatest. In this study, no clear relationship existed between forest buffer strip width (ranging from 30-60 m) and the level of stream warming observed at the monitoring stations. Keywords: terrain attributes, solar radiation, land cover, forest buffers, New Brunswick regulations, spatial modelling, DEM, forest covertypes
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Betis, Hermine, André St-Hilaire, Claude Fortin, and Sophie Duchesne. "Development of a water quality index for watercourses downstream of harvested peatlands." Water Quality Research Journal 55, no. 2 (March 9, 2020): 119–31. http://dx.doi.org/10.2166/wqrj.2020.007.
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Abstract This study aimed to adapt the Water Quality Index of the Canadian Council of Ministers of the Environment (CCME WQI) for its application to water quality assessment of drainage water and watercourses downstream of peat harvesting operations. It integrates different parameters that potentially reflect the overall water quality condition of a stream. Thus, it is calculated using multivariate water quality data and accounts for their conformity with respect to water quality guidelines. Adaptation of the index proceeded to identify, through a literature review, the physico-chemical parameters that may change due to peat harvesting. The CCME WQI was used to compare water quality of receiving watercourses to that of streams located within a 200 km radius from the study sites in three regions of Quebec. The availability of water quality data guided the selection of parameters among those identified. They are ammonia, conductivity, pH and suspended sediment concentrations. Results indicated a significant difference between WQI values of water from harvested peatlands and those of streams in two of the three regions studied. Results have also shown that it is the pH guideline that is not respected in most cases for harvested peatlands. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).
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Rose, P. M., M. J. Kennard, F. Sheldon, D. B. Moffatt, and G. L. Butler. "A data-driven method for selecting candidate reference sites for stream bioassessment programs using generalised dissimilarity models." Marine and Freshwater Research 67, no. 4 (2016): 440. http://dx.doi.org/10.1071/mf14254.
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Key issues with defining reference condition for stream bioassessment are (1) equivocal definitions of ‘minimally disturbed’ pressure criteria and wide-ranging approaches to site selection, (2) highly modified regions where near-pristine areas do not exist, leading to management decisions based on inconsistent and unquantified benchmarks and (3) costly field campaigns associated with ‘extensive spatial survey’ approaches. We used generalised dissimilarity modelling (GDM) to classify stream segments into ecotypes, and transparently and efficiently define candidate reference conditions for the Ecosystem Health Monitoring Program (EHMP) assessment area in south-eastern Queensland, a highly modified region with a complex biogeographic history. We modelled fish presence–absence data from 396 sites with GIS-based natural and anthropogenic predictors. Stream segments were classified into ecotypes using the GDM-transformed natural variables so that (1) reference-site selection adequately covered the β-diversity of the study area and (2) we could evaluate the validity of incorporating sites from neighbouring catchments outside of the EHMP assessment area. Relationships between selected anthropogenic variables (the river disturbance index and %stream connectivity) and fish assemblages were used to define pressure criteria and map candidate reference conditions. We conclude by describing a new framework that can be used to select indicator-specific reference sites by GDM and a stratified, probabilistic sampling design.
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Hannum, Mashita Fauzia, I. Putu Santikayasa, and Muh Taufik. "The Use of Dam Environmental Vulnerability Index (DEVI) for Assessing Vulnerability of Bengawan Solo Watershed, Indonesia." Agromet 34, no. 2 (December 9, 2020): 110–20. http://dx.doi.org/10.29244/j.agromet.34.2.110-120.
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Bengawan Solo is the longest river in Java, but current conditions show that its watershed is in a critical condition. Deforestation was very intensive in the last three decades that contributed to degradation of the watershed. Other factor contributing to the degradation is dam construction. However, our knowledge on the impact of dam construction on the environment and its vulnerability is poorly understood. Here, we assessed vulnerability of the watershed based on physical properties such as existing dams, morpho-dynamic activities, and deforested area. The study aims to identify the vulnerability of the Bengawan Solo watershed based on dam environmental vulnerability index (DEVI) approach, and to analyse the dominant variable contributing to DEVI. For calculating DEVI, several data were needed including land cover, rainfall, stream water stage, soil type, stream network, and dams. The results showed that Bengawan Solo watershed had moderate to high vulnerability (60%). Moderate level was identified for Madiun and Wonogiri sub-watershed, while high level was in Cepu and Babat sub-watershed. Our findings revealed that morpho-dynamic activities as represented by sediment rate and stream water stage had contributed to the high DEVI value as in Cepu and Babat sub-watershed. Further, influence of dams in this research was not dominant implying that any improvement to the DEVI approach remains research challenges. The improvement of the approach is expected to better identify the impact of dam construction on environment, situated in other regions than Amazon, where it was firstly developed.
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Pastorino, Paolo, Marco Bertoli, Manuel Kušće, Piero Giulio Giulianini, Vasco Menconi, Marino Prearo, and Elisabetta Pizzul. "Liver Lipid Accumulation in European Bullhead (Cottus cobio) from a High-Mountain Lake: An Adaptive Strategy to Survive the Adverse Winter Season." Diversity 12, no. 12 (November 24, 2020): 442. http://dx.doi.org/10.3390/d12120442.
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The hypothesis that liver lipid accumulation in fish is an adaptive strategy to survive the winter in the high-altitude environment was assessed in this study. During summer 2019, specimens of Cottus gobio were sampled in 15 watercourses of Friuli Venezia-Giulia Region (Italy) to verify if hepatic steatosis is or not normally present in the species. To do this, hepatic vacuolization was assessed by histology using a semiquantitative score. Furthermore, C. gobio were also captured during the ice-free season at Dimon Lake (1872 m a.s.l.) and But Stream (520 m a.s.l.) to compare the trend in lipid accumulation: water temperature, hepatosomatic index (HSI), gonadosomatic index (GSI), Fulton’s condition factor (K), and lipid area percentage (lipid %) were measured monthly. Findings revealed that liver steatosis is rather common in C. gobio. However, the trend in lipid accumulation of this species differed between Dimon Lake and But Stream. Based on the HSI and the GSI, the reproductive cycles differed in fish from the two environments (April–May in But Stream; May–June in Dimon Lake). While K values remained unchanged in the But Stream specimens, significant changes were recorded for Dimon specimens. The increase in lipid % from July to August in the Dimon Lake specimens coincided with greater food availability. With the rapid drop in lake water temperature in October, the lipid % decreased due to slower metabolic rate and lipid utilization from liver stores. There was a slight decrease in lipid % in the But Stream specimens, indicating that lipids were not being accumulated. Introduced years ago, the Dimon Lake bullhead population has since adapted to the winter conditions at high elevation.
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Becker, Fernando Gertum, Silene de Carvalho, and Sandra Maria Hartz. "Life-history of the South American darter, Characidium pterostictum (Crenuchidae): evidence for small scale spatial variation in a piedmont stream." Neotropical Ichthyology 6, no. 4 (December 2008): 591–98. http://dx.doi.org/10.1590/s1679-62252008000400007.
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The present study compares the reproduction, condition and size of the small characiform fish, Characidium pterostictum, sampled at close sites differing in severity of flash flood effects. Data were obtained from seasonal samples in two sites situated 8 km apart in the same stream. In the upstream site, habitat is more severely affected by flash floods than in the downstream site, and this difference was hypothesized to produce differences in life history and individual reproduction trade-off patterns, as predicted by life-history theory. The results provided evidence for small-scale spatial variation in life-history and trade-off patterns within the studied population. At the most severely disturbed site, C. pterostictum displayed a trade-off pattern that favored reproductive life-span (e.g., larger size, higher and seasonally stable condition, larger mean size of mature females) over instantaneous reproductive output (lower gonadosomatic index), while the opposite pattern was observed in the less disturbed site. Because of the differences in disturbance effects between each sampling site, these results suggest that within-stream variability in the severity of hydrological disturbance can influence life-history patterns at small spatial scales. An implication of the results is that fish occupying areas that are hydrologically more variable within a stream are not necessarily at an energetic or reproductive disadvantage, but may be simply under environmental conditions that favor distinct patterns of energy allocation (or trade-offs) and population persistence, as predicted by life-history theory. Therefore, plasticity in life-history is expected to be common in stream fish populations that are widespread in a stream system with spatially variable or patchy habitat characteristics.
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Ian, Borg, and Micallef Brian. "Constructing a Financial Condition Index for a Small-Open Economy: The Case of Malta." Research in Applied Economics 10, no. 3 (September 10, 2018): 89. http://dx.doi.org/10.5296/rae.v10i3.13755.
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This paper develops a Financial Conditions Index (FCI) for Malta for the period 1996-2017. This index provides a summary measure of financial conditions by combining several financial variables, both domestic and foreign, that influence economic activity. The indicators in the FCI are grouped in four categories: interest rates, bank balance sheet, asset prices and external variables. The weights are derived using Principal Component Analysis (PCA) and cross-checked using simulations from STREAM, the Central Bank of Malta’s macro-econometric model. Financial conditions in Malta were relatively benign in the mid-to-late 90s, followed by a period of tightening in the early 2000s. Financial conditions improved again during the pre-crisis period but deteriorated during the financial crisis and remained tight until 2013. In recent years these have recovered and became broadly neutral by 2017. The proposed FCIs correlate the most with one to three quarters ahead real GDP growth, suggesting potential predictive capacity for short-term forecasting.
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Bareen, Firdaus-e., and S. H. Iqbal. "The autumn communities of freshwater hyphomycetes in the tributaries of the River Neelum." Canadian Journal of Botany 75, no. 7 (July 1, 1997): 1046–60. http://dx.doi.org/10.1139/b97-116.
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Freshwater hyphomycete communities of autumn, based on data generated by three techniques used simultaneously, were richer than those detected by these techniques used singly. The fungal communities in the acidic streams were poorer (28–32 species) than in the circumneutral streams (39–64 species). No significant correlation was found between number of fungal species and pH of the stream water. Combining the data from this study with those of studies by other authors using the same techniques, linear correlation and regression analyses revealed the significant negative correlation between species composition of communities in a stream and its pH. The number of fungal species in assemblages detected by different techniques used singly (e.g., filtration of stream water or examination of foam concentrate) or communities based on data generated by these techniques used simultaneously versus pH values formed a unimodal curve with a maximum at a pH between 6 and 7, mostly at 6.7. The conidial dynamics were influenced by the riparian vegetation. Conidium production from submerged deciduous and conifer litter was determined under laboratory conditions. Generally conidium production per disc was higher for Anguillospora longissima (Sacc. & Syd) Ingold, Flagellospora cumula Ingold, Lunulospora curvula Ingold, and Tetracladium marchalianum de Wildeman in deciduous leaves than conifer leaves. Heliscus lugdunensis Sacc. & Therry, Alatospora acuminata Ingold, and Articulospora tetracladia Ingold produced more conidia per disc in conifer than in deciduous leaves. Percentage similarity between spora produced by submerged substrate and stream spora was higher for deciduous substratum than for coniferous substratum in five circumneutral streams with a riparian vegetation dominated by deciduous trees. This index was higher for coniferous substratum in three acidic streams in which coniferous and deciduous trees were evenly distributed. The fungal communities in the Nosehri, Pathika, and Jabbar Camp streams showed higher values of species diversity than in other streams. Key words: freshwater, hyphomycetes, species diversity.
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Medeiros, A. S., C. E. Luszczek, J. Shirley, and R. Quinlan. "Benthic Biomonitoring in Arctic Tundra Streams: A Community-Based Approach in Iqaluit, Nunavut, Canada." ARCTIC 64, no. 1 (March 9, 2011): 59. http://dx.doi.org/10.14430/arctic4080.
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<p><span style="font-family: 'Times New Roman';">Recent residential, commercial, and industrial development in the catchments of several Arctic streams has heightened the need to assess these freshwater systems accurately. It was imperative to develop methods that would be both effective at judging ecological condition of tundra streams and suitable for use by local groups. An investigation of two streams influenced by urbanization in Iqaluit, Nunavut, was carried out between July and August each year in 2007 – 09. Simple summary metrics (e.g., Shannon Index) and multivariate analysis (DCA, RD A) both demonstrated biological impairment in the benthic community at site locations downstream of urbanized portions of a local stream. This impairment was characterized by a loss of diversity and a dramatic shift of the benthic community to one dominated by chironomids from the subfamily Orthocladiinae. Elevated levels of total nitrogen (TN) and total phosphorus (TP) and several metals (Zn, Sr, Rb, Al, Co, Fe) were also found to be significantly related to benthic assemblages within these disturbed areas. This investigation also addressed taxonomic sufficiency, indicating that while family-level taxonomic identifications were sensitive enough to differentiate between pristine and impacted stream sites, a more precise taxonomic identification of the dominant benthos taxa (Insecta: Diptera: Chironomidae) to sub-family/tribe level identified a significant shift towards pollution-tolerant taxa. This higher taxonomic resolution will allow for the adaptation of protocols and the use of simple summary metrics to be effective for a community-based biomonitoring program in Arctic tundra streams. </span></p>
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Stevens, Cameron E., Trevor Council, and Michael G. Sullivan. "Influences of Human Stressors on Fish-Based Metrics for Assessing River Condition in Central Alberta." Water Quality Research Journal 45, no. 1 (February 1, 2010): 35–46. http://dx.doi.org/10.2166/wqrj.2010.005.
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Abstract Economic developments in Alberta have resulted in widespread changes in land use that may deteriorate river conditions for fish. Fish assemblages were characterized with index of biological integrity metrics for the heavily-developed watershed of the Battle River, Alberta. Metric relationships with human stressors were quantified using regression and information theory methods. Although the fauna comprised 14 native species, 50% of the catch was white sucker (Catostomus commersoni Lacepede, 1803). Five statistically unrelated metrics were identified as being responsive to stressors: two trophic guilds, one habitat guild, one reproductive guild, and one measure of community structure. Regression showed that the cumulative effect of human developments, indexed as road density in the basin, was negatively linked to the relative abundance of lithophils and positively linked to the relative abundance of omnivores. Agriculture also threatened the integrity of fish assemblages. Stream sections with higher cattle densities in their basins had fewer lithophils and benthic invertivores; whereas stream sections with higher nutrient concentrations contained fewer species, as well as fewer top carnivores, but more true omnivores. Understanding effects of human footprints that are expanding in western Canada will be critical to the successful management of aquatic resources.
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Palm, Daniel, Eva Brännäs, and Kjell Nilsson. "Predicting site-specific overwintering of juvenile brown trout (Salmo trutta) using a habitat suitability index." Canadian Journal of Fisheries and Aquatic Sciences 66, no. 4 (April 2009): 540–46. http://dx.doi.org/10.1139/f09-016.
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Brown trout ( Salmo trutta ) site-specific overwintering was studied in an ice-covered stream in northern Sweden. We monitored 238 individually tagged juvenile trout (body length 120–204 mm) from late summer until late winter using portable passive integrated transponder tag equipment and related it to a habitat suitability index. Minimum habitat suitability index explained a large portion (66.8%) of the variation in the proportion of individuals that remained and overwintered at specific sites from late summer until late winter. Our study design detected three scales of overwinter movements: (i) individuals that remained within their tagging site (site-scale movements); (ii) individuals that moved to other reaches (reach-scale movements), which were probably the most common; and (iii) individuals that left the study stream (stream-scale movements). There were no differences in size at tagging among individuals that adopted different scales of movements. We suggest that habitat suitability index can be used as a tool to predict site specific residency and, thus, habitat conditions in stream reaches during winter.
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Samani, Aliakbar Nazari, Qiuwen Chen, Shahram Khalighi, Robert James Wasson, and Mohammad Reza Rahdari. "Assessment of land use impact on hydraulic threshold conditions for gully head cut initiation." Hydrology and Earth System Sciences 20, no. 7 (July 28, 2016): 3005–12. http://dx.doi.org/10.5194/hess-20-3005-2016.
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Abstract. A gully as an accelerated erosion process is responsible for land degradation under various environmental conditions and has been known as a threshold phenomenon. Although the effects of gullying processes have been well documented, few soil erosion models have taken into account the threshold condition necessary for gully development. This research was devoted to determining the effects of land use change on hydraulic threshold condition and stream power of water flow through an in situ experimental flume (15 m × 0.4 m). Results indicated that head cut initiation and detachment rates showed a better correlation to stream power indices than shear stress (τcr). The threshold unit stream power value (ωu) for head cut initiation in rangeland, abandoned land, and dry farming land was 0.0276, 0.0149, and 4.5 × 10−5 m s−1, respectively. Moreover, the micro-relief condition of soil surface and surface vegetation affected the flow regime of discharge and velocity. It is seen that the composite hydraulic criteria of Froude number (Fr) and discharge (Q) can clearly discriminate the land uses' threshold. In fact, the remarkable decrease of τcr in dry farming was related to the effect of tillage practice on soil susceptibility and aggregate strength. The findings indicated that using the unit steam power index instead of critical shear stress could increase the models' precision for prediction of head cut development. Compared to the Ephemeral Gully Erosion Model (EGEM) equation for critical shear stress, it is important to point out that for modelling of gully erosion, using single soil attributes can lead to an inaccurate estimation for τcr. In addition, based on the findings of this research, the use of threshold values of τcr = 35 dyne cm−2 and ωu = 0.4 cm s−1 in physically based soil erosion models is susceptible to high uncertainty when assessing gully erosion.
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Soo, Chen, Hairul Mahsol, Leonardo Jainih, Arman Fikri, Cheng Chen, and Nur Kamal. "Fish Biodiversity and Water Quality of Tropical Forest Streams Adjacent to the Western Boundary of Kinabalu Park, Sabah." Journal of Tropical Life Science 12, no. 2 (May 17, 2022): 261–68. http://dx.doi.org/10.11594/jtls.12.02.12.
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Modification and degradation of habitats outside the boundaries of a national parkmay result in the park's integrity being compromised. Thus, the present study aims todocument variation in freshwater fish and water quality of tropical forest streams adjacent to the western boundary of Kinabalu Park, Sabah. Concurrently, fish samplesand environmental parameters were collected at six stations covering a total streamline length of 10 km. The three most abundant species were Tor tambra (34.4%), Barbodes sealei (19.5%), and Lobocheilos ovalis (12.4%). Tor tambra exhibited a negative allometric growth pattern (coefficient < 3) and was in poor to fair condition (0.8< Fulton’s condition factor < 1.2). The highest fish abundance was found in downstream stations with species addition. Metrics of diversity, such as Shannon's diversityindex and the Margalef index of species richness, decreased as elevation increasedfrom 100 to 600 metres above sea level. The water quality of the forest streams isgood, classified as Class I and/or Class II by Malaysia's National Water Quality Standards, except for ammoniacal nitrogen at station 6, which was classified as Class III.Higher turbidity, orthophosphate, and ammoniacal-nitrogen values were found nearthe Podos village. In conclusion, the altitudinal gradient of fish biodiversity was observed in the forest streams near Kinabalu Park. Regular water quality monitoring ofthe downstream river is necessary, as indicated by the potential domestic impacts onthe river.Keywords: Biodiversity, Elevation, Freshwater fish, Forest stream, Kinabalu Park
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Villares Junior, GA, and R. Goitein. "Differences in the feeding of Rhamdia quelen (Siluriformes, Heptapteridae) in four distinct lotic systems." Brazilian Journal of Biology 75, no. 3 (August 25, 2015): 650–54. http://dx.doi.org/10.1590/1519-6984.20313.
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AbstractThe aim of this study was to compare the food composition of Rhamdia quelen in four distinct order rivers. It was performed at a low part at the basin of the Sorocaba river in systems classified as first (Anastácio stream), second (Nego stream), fifth (Tatuí river) and sixth (Sorocaba river) orders. Collections were performed every month between January and December of 2011. The stomach contents were examined by using the alimentary index (IAi) and compared by the non-parametric method non-metric multidimensional scale ranking (NMDS) with the Spearman rank correlation. A diet difference was observed for individuals of the smaller systems (Anastácio and Nego streams) and the larger ones (Tatui and Sorocaba rivers), represented respectively by allochthonous and autochthonous organisms compounding their diets. Marginal vegetation and its interaction with the water conditions may respond to these composition differences.
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Lachhab, Ahmed, Matthew Beren, and Brian Zuidervliet. "Middle Creek Water Assessment Using Water Quality Index (WQI)." Journal of the Pennsylvania Academy of Science 88, no. 1 (March 1, 2014): 4–12. http://dx.doi.org/10.5325/jpennacadscie.88.1.0004.
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ABSTRACT Water quality Index (WQI) provides a single value to express overall quality of water which is calculated based on a number of measurable parameters. WQI was calculated based on 10 parameters that were determined during the period between June and July of 2012 and July of 2013 in an effort to assess the water quality of Middle Creek (MC) (Snyder, CO. PA). The Middle Creek (MC) is a 2nd order tributary stream flowing into Penn's Creek before joining the Susquehanna River. In this study, eleven sites were selected along MC between the head waters and its confluence with Penn's Creek. Physical properties were measured in the field, and grab-samples were tested for P, NO2−, NO3−, NH3, biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS). The Composite WQI for all sites along MC was calculated to be 89.71, indicating that MC is in good condition regarding water quality and is capable of buffering nutrient and chemical runoff. Results have shown that certain parameters, such as temperature (T°), COD or BOD, can be used as proxies for predicting the WQI. Due to good correlation with WQI values, T°, COD or BOD can be used to assess water quality within a short period of time. In this study, T° and COD were found to give the best forecasting parameters, followed by BOD. The relationships found between WQI and these three parameters, allow for a simple test to provide an adequate assessment of the water quality of a given stream system.
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Poulton, Barry C., and Jing Tao. "Evaluation of EPT macroinvertebrate metrics in small streams located within the non-connected stormwater management region of Kansas City, Missouri, USA." Transactions of the Missouri Academy of Science 47, no. 2019 (January 1, 2019): 21–34. http://dx.doi.org/10.30956/mas-29r1.
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Abstract During 2012-2014, we evaluated macroinvertebrate communities in streams draining the non-connected stormwater management region (Municipal Separate Storm Sewer System, or MS4) within the Kansas City metropolitan area utilizing the Missouri bioassessment protocols. Trends in aquatic life impairment status based on Missouri's Macroinvertebrate Stream Condition Index (MSCI), as well as richness and abundance of EPT indicator metrics (Ephemeroptera, Plecoptera, Trichoptera), were compared between rural control sites and both transitional and urban stream sites representing varying stages of land use conversion. As compared to non-urban control sites, EPT taxa richness was significantly lower at MS4 urban sites during all three years (p = 0.007 – 0.013) and MS4 transitional sites during one of three years (p=0.48). EPT abundance (%) was significantly lower at MS4 urban sites during all years (p = 0.008 – 0.013) and MS4 transitional sites during one of three years (p=0.34). Mean EPT abundances ranged between 0.6% - 10.3% at urban MS4 sites, and always exceeded 18% at control sites. Both EPT richness and abundance were lower at the MS4 control site but means for EPT and other core metrics at this site were most often similar to non-urban control sites based on analysis of variance (ANOVA). MS4 transitional sites with active development in their watersheds were partially-supporting in their impairment status, and EPT metrics had lower means and generally more variability than control sites. Temporal trends indicate non-urban control and MS4 control sites consistently meet fully-supporting impairment status based on overall MSCI scores, but no study sites currently meet regional expectations (as defined by state reference streams) for either of the EPT metrics. Results indicate that Missouri and Kansas biocriteria for both EPT metrics are not consistently being met at any stream sites in the Kansas City metro area, including fully-supporting control sites and MS4 streams that receive stormwater runoff in watersheds with urban development that is well-established or currently transitioning to urban or suburban land uses.
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Scheerer, Nichole E., Anupreet K. Tumber, and Jeffery A. Jones. "Attentional demands modulate sensorimotor learning induced by persistent exposure to changes in auditory feedback." Journal of Neurophysiology 115, no. 2 (February 1, 2016): 826–32. http://dx.doi.org/10.1152/jn.00799.2015.
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Hearing one's own voice is important for regulating ongoing speech and for mapping speech sounds onto articulator movements. However, it is currently unknown whether attention mediates changes in the relationship between motor commands and their acoustic output, which are necessary as growth and aging inevitably cause changes to the vocal tract. In this study, participants produced vocalizations while they heard their vocal pitch persistently shifted downward one semitone in both single- and dual-task conditions. During the single-task condition, participants vocalized while passively viewing a visual stream. During the dual-task condition, participants vocalized while also monitoring a visual stream for target letters, forcing participants to divide their attention. Participants' vocal pitch was measured across each vocalization, to index the extent to which their ongoing vocalization was modified as a result of the deviant auditory feedback. Smaller compensatory responses were recorded during the dual-task condition, suggesting that divided attention interfered with the use of auditory feedback for the regulation of ongoing vocalizations. Participants' vocal pitch was also measured at the beginning of each vocalization, before auditory feedback was available, to assess the extent to which the deviant auditory feedback was used to modify subsequent speech motor commands. Smaller changes in vocal pitch at vocalization onset were recorded during the dual-task condition, suggesting that divided attention diminished sensorimotor learning. Together, the results of this study suggest that attention is required for the speech motor control system to make optimal use of auditory feedback for the regulation and planning of speech motor commands.
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Olichwer, Tomasz, Robert Tarka, and Sebastian Buczyński. "Impact of North Atlantic Oscillation on water resources in South Western Poland." Acque Sotterranee - Italian Journal of Groundwater 10, no. 4 (December 23, 2021): 15–24. http://dx.doi.org/10.7343/as-2021-530.
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The paper presents the influence of the North Atlantic Oscillation (NAO) on the water resources, especially considering groundwater discharge (baseflow) in south-western Poland. The impact of long-term changes of meteorological conditions on the water resources of this area in the 1966-2015 was determined on the basis of changes in the baseflow and total stream flow. Statistical analysis of meteorological and hydrological data showed that the runoff from the Sudeten mountain range and its foreground depends on the circulating climate factors (like the NAO). The annual NAO index best describes the variability of the average annual (12-month) total stream flow and groundwater discharge calculated from February to January and March to February, while the winter NAO index best describes the variability of the average annual (12-month) total stream flow and groundwater discharge calculated from March to February and April to March. The winter NAO index also best describes the variability of the average six-month (6-month) stream flow and groundwater discharge calculated from April to September. In the above-mentioned cases, the values of the Pearson correlation coefficient are at a high level and reach the value of -0.65.
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Park, Se-Rin, Suyeon Kim, and Sang-Woo Lee. "Evaluating the Relationships between Riparian Land Cover Characteristics and Biological Integrity of Streams Using Random Forest Algorithms." International Journal of Environmental Research and Public Health 18, no. 6 (March 19, 2021): 3182. http://dx.doi.org/10.3390/ijerph18063182.
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The relationships between land cover characteristics in riparian areas and the biological integrity of rivers and streams are critical in riparian area management decision-making. This study aims to evaluate such relationships using the Trophic Diatom Index (TDI), Benthic Macroinvertebrate Index (BMI), Fish Assessment Index (FAI), and random forest regression, which can capture nonlinear and complex relationships with limited training datasets. Our results indicate that the proportions of land cover types in riparian areas, including urban, agricultural, and forested areas, have greater impacts on the biological communities in streams than those offered by land cover spatial patterns. The proportion of forests in riparian areas has the greatest influence on the biological integrity of streams. Partial dependence plots indicate that the biological integrity of streams gradually improves until the proportion of riparian forest areas reach about 60%; it rapidly decreases until riparian urban areas reach 25%, and declines significantly when the riparian agricultural area ranges from 20% to 40%. Overall, this study highlights the importance of riparian forests in the planning, restoration, and management of streams, and suggests that partial dependence plots may serve to provide insightful quantitative criteria for defining specific objectives that managers and decision-makers can use to improve stream conditions.
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Özçiçek, Esin, and Kenan Köprücü. "COMPARISON OF CONDITION, GONADOSOMATIC INDEX AND SOME NUTRITIONAL VALUES OF DIFFERENT AGE AND SIZED SALMO TRUTTA CAUGHT FROM MUNZUR STREAM (TUNCELİ) BEFORE, DURING AND AFTER BREEDING PERIOD." NWSA Academic Journals 17, no. 4 (October 29, 2022): 225–31. http://dx.doi.org/10.12739/nwsa.2022.17.4.5a0182.
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Bogdanović, Gordana, Dženita Ljuca, Edin Ostrvica, Adnan Babović, Enida Nevačinović, and Hidajet Rahimić. "Doppler measurements of feto-placental blood stream in pregnant smokers." Journal of Health Sciences 1, no. 3 (December 15, 2011): 159–65. http://dx.doi.org/10.17532/jhsci.2011.131.
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Introduction: Doppler analysis of the feto-placental and fetal circulation give dynamic information on the condition of the bloodstream during pregnancy, and early detection of fetal hypoxia. The objectives of the study were: testing whether there is influence of smoking on feto-placental circulation; determining whether there is a link to a number of smoked cigarettes during the day; assessing the benefits of Doppler ultrasonographic screening in detection of fetal hypoxia in pregnant women who smoke during pregnancy.Methods: 300 pregnancies were included in the prospective research. With regard to a number of smoked cigarettes the pregnant women were divided into three groups: I. the first group (moderate smokers) consisted of 100 pregnant women who smoked up to 15 cigarettes a day during pregnancy; II. the second group (heavy smokers) 100 pregnant women who smoked more than 15 cigarettes a day during pregnancy and III. the third group (control group) 100 pregnant women who did not smoke during pregnancy. All pregnant women underwent Doppler measurements of blood circulation (determination of resistance index – RI) in the umbilical artery, fetal aorta and middle cerebral artery.Results: The intensity of smoking has influence to circulation because RI in the umbilical artery and fetal aorta is increased and RI is decreased in the middle cerebral artery in pregnant women heavy smokers in comparison to pregnant women moderate smokers.Conclusion: Doppler sonography of the blood vessels could have an important role in detection of hypoxia and monitoring of the condition of the fetus of pregnant women who smoked during pregnancy.
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Leonard, Jill BK, and Stephen D. McCormick. "Metabolic enzyme activity during smolting in stream- and hatchery-reared Atlantic salmon (Salmo salar)." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 8 (August 1, 2001): 1585–93. http://dx.doi.org/10.1139/f01-105.
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To evaluate the metabolic differences between Atlantic salmon (Salmo salar) parr and smolts and the effect of rearing environment, we examined metabolic enzyme activity in white muscle, liver, and heart in stream- and hatchery-reared juveniles. Spring increases in gill Na+,K+-ATPase (3.5-fold) and cardiosomatic index (3769%) and decreases in condition factor (~17%) occurred in smolts, but not in parr. White muscle phosphofructokinase (PFK) increased during spring and was 3.6-fold higher in smolts than in parr by late spring. There were seasonal increases in liver citrate synthase (CS) (~42%), liver β-hydroxyacyl-coenzyme A dehydrogenase (HOAD) (~60%), and heart CS (~23%) and decreases in liver lactate dehydrogenase (LDH) (~28%) in parr and smolts. Activity of liver HOAD was greater in stream-reared smolts (~18%) than in parr or hatchery smolts. Heart PFK activity increased during spring in wild-reared parr and smolts, while it decreased in hatchery-reared smolts. White muscle LDH and PFK increased earlier in spring in hatchery- than in stream-reared smolts. Our results suggest that increased heart size and high white muscle PFK occur during smolting and may be adaptive for downstream and ocean migration. Hatchery- and stream-reared Atlantic salmon differ in the timing of metabolic changes during smolting, which may impact their long-term survival.
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Van Derveer, William D., Royal J. Nadeau, and Georgia L. Case. "A SCREENING-LEVEL EVALUATION OF IMPACTS TO A MONTANA LOTIC MACROINVERTEBRATE COMMUNITY FROM A FUEL OIL SPILL." International Oil Spill Conference Proceedings 1995, no. 1 (February 1, 1995): 391–97. http://dx.doi.org/10.7901/2169-3358-1995-1-391.
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ABSTRACT A pipeline rupture during the winter of 1993 released an undetermined amount of refined fuel into a small stream on the Flathead Indian Reservation in Montana. A screening-level bioassessment was performed in conjunction with supporting sediment and water analytical chemistry, to provide a preliminary evaluation of the effects of the spill and subsequent remedial response actions on the benthic community. A variety of community-level metrics were compared to the habitat scores to evaluate the biological condition of each station sampled relative to the reference, thereby isolating effects related to contaminant release from those due to background habitat conditions. A comparison of taxa richness and Ephemeroptera: Plecoptera: Tricoptera (EPT) Index values from March 1993 to March 1994 indicated partial recovery at the rupture point after intensive soil cleanup and remediation activities. Approximately one year following the spill, the rupture point exhibited 60 and 75 percent recovery respectively in taxa richness and EPT Index. At farther downstream stations, ≤15 and <10 percent recovery in taxa richness and EPT Index respectively were observed.
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Greenwood-Smith, S. L. "The use of rapid environmental assessment techniques to monitor the health of Australian rivers." Water Science and Technology 45, no. 11 (June 1, 2002): 155–60. http://dx.doi.org/10.2166/wst.2002.0390.
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River managers require tools to assess the ecological condition of waterways and prioritise management strategies. As benchmarking the condition of an entire waterway with detailed surveys is often not practical, Rapid Environmental Assessment Techniques have been developed to provide an indication of the state of a river's health, both rapidly and at a low cost. In this investigation, three such techniques, developed recently in Australia, are applied to the same creek in order to compare the outcomes and the levels and types of resources required for their application. The output from the three indices ranges from descriptive to statistically analysed data, making them difficult to compare directly. Overall, the three indices all report that the sample creek had relatively poor health. The results from the Victorian Index of Stream Condition and New South Wales' Pressure, Biota, Habitat Stream Assessment appear to correlate well. An important finding of the investigation is the variation in the resources required to apply each assessment technique. Generally, the resource demands increase with the requirement for a higher level of scientific rigour. The methods are either relatively inexpensive and rapid to undertake or more resource intensive, yet thorough in the data collected. A two step process incorporating the techniques in a cost-effective manner is recommended.
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Oliveira, S. V., and R. M. V. Cortes. "A biologically relevant habitat condition index for streams in northern Portugal." Aquatic Conservation: Marine and Freshwater Ecosystems 15, no. 2 (2005): 189–210. http://dx.doi.org/10.1002/aqc.671.
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