Upland Streams Research Articles

Two-year assessment of the effects of controlled sediment flushing on stream habitats and biota at reach scale

Controlled sediment flushing operations (CSFOs) allow to recover reservoirs storage loss while rebalancing the sediment flux interrupted by dams but, at the same time, may cause unacceptable ecological impact. In this study, we investigated the responses of the food web of an upland stream to a CSFO, focusing on the effects of fine sediment deposition detected in three different mesohabitats, i.e., a pool, a riffle, and a step-pool. The field campaign lasted two years and included repeated measurements of fine sediment deposits, and sampling of periphyton, benthic macroinvertebrates and fishes. A moderate and patchy deposition occurred due to the CSFO with short and medium-term ecological impact on the lower trophic levels of the food web, which may affect the whole ecosystem functioning. The monitoring of all available mesohabitats in the investigated stream allowed to detect variations in the ecological response to CSFO, providing a more adequate assessment of the impact. As expected, sedimentation was larger in the pool but, in contrast to our hypotheses, the impact was lower and the recovery was longer for the benthic organisms inhabiting the riffle. In the case of fishes, no lethal impact of both brown trout and bullhead was recorded in the short term but the occurrence of longer lasting effects could not be excluded. To date, this is one of the few studies dealing with a detailed integrative assessment of the downstream impact of sediment management from reservoir on both abiotic and biotic components of stream ecosystem.

Continuous Wavelet Transform Analysis of Climate Variability, Resiliency, and Restoration Strategies in Mesohaline Tidal Creeks

This research article employs the continuous wavelet transform analysis to identify the climatological effects among various water quality parameters to identify the successfulness of upland stream restoration on the receiving mesohaline tidal creeks. Estuaries and their corresponding tidal creeks have been impacted by human anthropogenic influences for decades, allowing a variety of restoration practices to be implemented in upland streams. In the face of climate variability and continuous human development pressures, this research performs statistical analysis and a wavelet coherence on, before, and after stream restoration for water quality changes in Chesapeake Bay’s tidal tributaries in the Lower Western Shore to identify if the restoration strategies have been effective in the mesohaline tidal creeks. Statistical analysis showed that currently, the receiving tidal basins are not seeing the required positive improvements in water quality after years of upland stream restoration. Compounding this is the fact climate variability cannot be ignored. Results indicate that the North Atlantic Oscillation (NAO) has significant wavelet coherence with bottom dissolved oxygen, precipitation, and nutrients. This suggests that current restoration efforts may not be able to keep up with climate variability, and other techniques (restoration or policies) may need to be implemented.

An Examination of Stream Water Quality Data from Monitoring of Forest Harvesting in the Eastern Highlands of Victoria

A large data set measuring surface stream turbidity, dissolved oxygen levels, and water temperature was developed by sampling 32 rivers and streams with forested catchments at weekly intervals for between two and three years. This was in response to allegations of possible water quality impairment by forest harvesting (“logging”). Additionally, nine rivers or streams external to the forests were sampled to form a “reference set”; concern was expressed that the water quality of these may be impaired by upstream forest harvesting. An unlogged forested control catchment was selected from the data set and used as a comparator to help reduce seasonal variation. Division of the data into “logged forested catchments” and “unlogged forested catchments” allowed for us to test the null hypothesis. The null hypothesis was that there was no difference between the means of the logged and unlogged sets by a “Student’s t test of difference between means”. The null hypothesis was supported for the three parameters. There was no discernible deterioration in water quality associated with the presence of logging in the stream catchments. It was concluded that logging in this environment was not a determinant of water quality, and that the presence or absence of logging in these catchments did not affect the measured water quality. Spearman rank correlation analysis was unable to detect any statistically significant correlations between the water quality parameters, suggesting they are substantially independent measures of water quality. The monitoring showed that the small upland streams had generally good-to-excellent water quality. The water quality in these was generally better than the “reference set”—this probably reflected agriculture and cultivation in the proximity of their sampling points.

Effects of natural flood management woody dams on benthic macroinvertebrates and benthic metabolism in upland streams: Importance of wood‐induced geomorphic changes

AbstractNatural Flood Management (NFM) aims to reduce flood hazard by working with nature and is gaining prominence worldwide. One particular NFM technique involves the use of channel‐spanning woody dams that maintain a clearance height above baseflow. These dams function by increasing channel roughness during high flows and by forcing excessive water onto the floodplain. Whether these dams provide additional benefits to nature remains unclear. While there are many existing studies on natural in‐stream wood structures, very few have documented the impact of NFM woody dams in particular. This study adopted a multidisciplinary approach and a Before–After Control–Impact (BACI) research design to assess whether NFM woody dams installed in a small upland catchment had driven changes in benthic macroinvertebrate assemblages and benthic metabolic activities through the geomorphic changes that they had created. Statistical results indicate that macroinvertebrate density, richness, and diversity did not show any difference between stream reaches with and without NFM woody dams. The metrics were generally not related to grain‐size parameters and volumes of sediments eroded or deposited. However, individual genera such as Baetis and Rhithrogena became more dominant in the control reach towards the end of the study period, likely due to the higher flow velocities and coarser sediments there resulting from the lack of flow resistance in the absence of NFM woody dams. Rates of benthic respiration (but not rates of photosynthesis) were consistently significantly higher in woody dam reaches than in control reaches, likely due to the presence of patches of finer sediments in the former.

Environmental correlates with fish assemblage change and biotic homogenization across 40 years in an Ozark, Gravel‐Bed river basin

AbstractFish assemblages in freshwater ecosystems are becoming more homogenous from multiple abiotic, environmental, and physicochemical variables at different scales. Historical fish collections (1976–1977) by Billy Michael Johnson and Dr. Johnson K. Beadles were compared to contemporary fish collections (2018–2019) in tributaries of the Eleven Point River basin in Arkansas to examine patterns of fish assemblage change. Fish assemblage change variables were compared to pasture land use/land cover (LULC) at multiple scales and in‐stream habitat variables to understand relationships and discover potential correlates suggesting biotic homogenization. Fish assemblages in the Eleven Point River basin of Arkansas have experienced significant spatiotemporal changes, and LULC change and habitat alterations may have influenced this process. Increased tolerant species and decreased intolerant species at sites contributed to biotic homogenization, particularly in pool habitats. Surprisingly, expansion of some intolerant fishes was also observed that tend to occupy riffles. Sites with high percentages of pasture LULC at finer spatial scales typically had more homogenised fish assemblages. We hypothesized gravel aggradation from local pasture land use has degraded pools and increased riffle habitat, resulting in homogenised fish assemblages in the Eleven Point River basin over the study period. Few studies link LULC, in‐stream habitat, and biotic homogenization when examining fish assemblage change over time, and these dynamics can be particularly complex in upland streams experiencing gravel aggradation. Similar research in other upland, gravel‐bed river systems would provide a broad understanding of the presented environmental associations.

'One River, Two Systems': Hong Kong's River Management.

Hong Kong (HK), one of the world's most densely populated metropolises, is home to over 200 rivers and streams extending about 2500 km in length. During the 1970s-1990s, most of these rivers were converted into artificial canals, to which the local society pays little attention. Since the 2010s, the HK government has initiated river revitalization to enhance the social-environmental roles of rivers. This study employed a mixed research method, including literature and policy analysis, expert interviews, field visits, and a public survey, to identify key challenges in HK's Integrated River Basin Management (IRBM). The findings highlighted the lack of IRBM's institutional arrangements in HK, characterized by a fragmented 'one river, two systems' approach without both coordination and collaboration. The Water Supplies Department (WSD) impounds upland streams as reservoirs for securing the local water supply, while the Drainage Service Department (DSD) manages heavily channelized, culverted downstream serving as storm drains with diminished ecological functionality. One significant barrier to the implementation of IRBM in HK was the limited public participation, although our survey revealed a high level of public willingness to participate in river management. Presently, river revitalization efforts have achieved limited success, with ecological measures appearing mostly "cosmetic" and the conservation of freshwater biodiversity neglected. This further underscored the pressing need for the embracement of IRBM in HK to safeguard basin-wide freshwater ecosystems. Our survey also indicated low public awareness of river revitalization initiatives and widespread dissatisfaction with their outcomes. In conclusion, we proposed the development of IRBM in HK by instituting river basin coordination, prioritizing river ecosystem restoration in revitalization projects, and involving the public through tailored strategies.

Water characterization of Igarapés used in fish farming in Manaus and Iranduba, Amazonas, Brazil

The objective was to study the impacts of the implementation of fish farming projects (fish breeding), the quality of water effluents from these enterprises, in upland streams on properties in the municipalities of Manaus and Iranduba. We chose to monitor some physical-chemical attributes such as turbidity, dissolved oxygen, chlorophyll-a, ammonia, nitrite, nitrate and phosphorus because they are able to establish a relationship between fish farming and the loss of environmental quality of water. For this study, 16 sample units were analyzed, with two collection points each, upstream and downstream in the fish farming enterprises in uplands of continuous land (continuous flow), in two different periods in the year 2016 and 2017. The main variables studied in the analysis stage of an aquatic ecosystem, including fishing grounds, they can be: water temperature, pH, turbidity, concentration of nutrients (nitrite, nitrate and ammonia, total phosphorus), dissolved oxygen, chlorophyll. There was no significant difference in temperature, dissolved oxygen, ammonia and nitrate. There was a significant difference for the depth, turbidity and nitrite parameters. There was a significant difference for phosphorus and pH and no difference was observed for chlorophyll-a. The analyzed parameters were sufficient to demonstrate that the fish farming activity in Igarapé alters turbidity, nitrite and phosphorus and pH. Based on these parameters, better control of water quality in fish farming in Igarapé is suggested as water flow and better quality of the feed offered to fish.

Using baited remote underwater videos to survey freshwater turtles

AbstractNew and innovative techniques utilizing underwater cameras have the potential to track changes in turtle populations whilst being less invasive and time intensive than traditional trapping surveys. In this study, we trialled the use of Baited Remote Underwater Videos (BRUVs) in five upland streams to test if BRUVs could be used for abundance, size and sex estimates of freshwater turtles. We also compared BRUVs to cathedral traps and identified key considerations for future use of this method, such as whether the time of day influenced results. Our study successfully detected 83 turtles from 52 h of footage and identified all species known to occur in the study area. The deployment time did not significantly influence relative abundance. BRUVs also produced statistically similar catch per unit effort estimates to cathedral trapping techniques. No small turtles (i.e. juveniles) were detected, and difficulties with visibility, sex accuracy and carapace measurements are discussed for future BRUV use. Our study shows that BRUVs are a useful, time effective, non‐invasive technique to collect relative abundance and species richness estimates for freshwater turtles.

Loss of functionally important and regionally endemic species from streams forced into intermittency by global warming.

Climate change is altering hydrological cycles globally, and in Mediterranean (med-) climate regions it is causing the drying of river flow regimes, including the loss of perennial flows. Water regime exerts a strong influence over stream assemblages, which have developed over geological timeframes with the extant flow regime. Consequently, sudden drying in formerly perennial streams is expected to have large, negative impacts on stream fauna. We compared contemporary (2016/17) macroinvertebrate assemblages of formerly perennial streams that became intermittently flowing (since the early 2000s) to assemblages recorded in the same streams by a study conducted pre-drying (1981/82) in the med-climate region of southwestern Australia (the Wungong Brook catchment, SWA), using a multiple before-after, control-impact design. Assemblage composition in the stream reaches that remained perennial changed very little between the studies. In contrast, recent intermittency had a profound effect on species composition in streams impacted by drying, including the extirpation of nearly all Gondwanan relictual insect species. New species arriving at intermittent streams tended to be widespread, resilient species including desert-adapted taxa. Intermittent streams also had distinct species assemblages, due in part to differences in their hydroperiods, allowing the establishment of distinct winter and summer assemblages in streams with longer-lived pools. The remaining perennial stream is the only refuge for ancient Gondwanan relict species and the only place in the Wungong Brook catchment where many of these species still persist. The fauna of SWA upland streams is becoming homogenised with that of the wider Western Australian landscape, as drought-tolerant, widespread species replace local endemics. Flow regime drying caused large, in situ alterations to stream assemblage composition and demonstrates the threat posed to relictual stream faunas in regions where climates are drying.

Late Glacial and Holocene evolution of the estuarine section of the Nida River

Based on the results of detailed geological-geomorphological studies, old maps from the past 200 years, and historical data, the paper is the first to present the structure of the valley floor in the estuary of the Nida River, an upland tributary of the Vistula, and discuss changes in the development and course of their channels. The aim of the study was to grasp the importance of local factors, both natural (palaeogeographical, lithological and tectonic) and anthropogenic, in the morphogenesis of this section, where a relatively small upland stream crossed in the medieval and modern periods by important overland and water routes of the Polish-Lithuanian Commonwealth flows into the Vistula River, which is ten times larger. The discussed section is not deltaic in character. The branching of the Nida into several simultaneously functioning outlet arms may have been caused by the blocking of outflow from the valley during floods and the drainage of the flood waters at the valley mouth in several directions, via channels both permanent and periodic. Changes in the numbers and locations of the Nida estuaries in recent centuries have both natural and anthropogenic causes. The interaction between the main stream and its many-times smaller tributary in the studied section has resulted in a complex mosaic of forms and cut-and-fills of both streams, but with the Vistula playing the dominant role. The cut-and-fills of the Vistula “enclose” the Nida alluvium inside its valley on the Winiary-Nowy Korczyn line, while the cut-and-fills of the Nida only occur in a very narrow strip under the edge of the terrace. The Nida followed abandoned channels of the Vistula on Holocene cut-and-fill IIA, flowing parallel to the Vistula for 9 km. The floor of the Nida Valley lacks Holocene mineral-organic and mineral sediments, characteristic of other upland tributaries from loess areas. The regulation of the Vistula in the mid-19th century and the Nida in the first half of the 20th century fixed the courses of the rivers, completely changing the sedi­mentation regime in the estuarine section of the Nida, where backflow and associated sedimentation of fine-grained deposits occurred.

Ecological assemblages of Hydrachnidia as bioindicators of water quality in the upland streams of Garhwal Himalayas

Ecological assemblages of Hydrachnidia as bioindicators of water quality in the upland streams of Garhwal Himalayas

High summer temperatures are associated with poorer performance of underyearling Atlantic salmon (Salmo salar) in upland streams.

Future warming scenarios are predicted to result in an increased frequency of high, and potentially stressful, temperatures in aquatic ecosystems. Here we examined whether the performance of wild underyearling Atlantic salmon (Salmo salar) in Scottish streams stocked with identical egg densities was influenced by thermal stress. Biomass and density declined with degree hours exceeding 23°C, indicating apparent mortality or emigration as a possible result of exposure to high temperatures. These results strengthen the need for further action such as riparian tree planting to reduce stream summer temperatures.

Plastic recycling plant as a point source of microplastics to sediment and macroinvertebrates in a remote stream.

The online version contains supplementary material available at 10.1186/s43591-022-00045-z.

Hydromorphological preferences of freshwater pearl mussel (Margaritifera margaritifera) in upland streams of the Bavarian Forest – A case study

The freshwater pearl mussel is a highly specialized freshwater bivalve. In four pearl mussel streams located in the Bavarian Forest, hydromorphological microhabitat conditions were investigated in mussel colonized and adjacent non-colonized river stretches to describe hydromorphologic preferences of freshwater pearl mussel. For that purpose, tachymetry, flow velocity and substratum composition were investigated. Hydraulic-numerical models were calculated to predict flow velocities, maximal shear stress and substratum stability under different discharge scenarios. Results indicate that pearl mussels prefer river stretches with certain minimal currents during low flow but at the same time stable substrata even during bankfull discharge. Implications for habitat restoration and release of juvenile mussels from breeding programs are discussed.

Geomorphic effects of natural flood management woody dams in upland streams

AbstractOne popular Natural Flood Management (NFM) technique involves the construction of channel‐spanning woody dams in low‐order streams that maintain a clearance height above base flows. While extensive research has examined the geomorphic effects of natural wood accumulations, little has been documented of NFM woody dams, which are structurally distinct from natural accumulations and may produce different patterns of erosion and deposition. This consideration is crucial because changes in physical habitat characteristics have implications for flood management objectives as well as ecosystem structure and functioning. This study adopted a Before‐After Control‐Impact (BACI) design to assess the geomorphic effects of NFM woody dams in the upper River Cover catchment, United Kingdom. One baseline survey prior to and three monitoring surveys up to 2 years following dam construction were conducted. Structure‐from‐Motion (SfM) photogrammetry was employed to capture topographic change, supplemented by bathymetric surveys. Results highlight that where the dams remained secure in place, they promoted in‐stream habitat diversity by creating underflow pools. Sediment storage was observed only where the dams had clearance heights <0.3 m from the stream bed. Additionally, the dams commonly led to bank erosion, likely enhanced by inherent bank instability in the study catchment as observed along the control reaches. However, volumes of sediments eroded and deposited were not statistically different between the control and woody dam reaches. Longer monitoring is required to determine whether these effects on channel morphology and habitat diversity will persist, amplify, or diminish over time, and to better understand the longevity of NFM woody dams.

The body condition of invasive crayfish Faxonius limosus (Raf., 1817) (Decapoda: Cambaridae) is better in small rivers than in dam reservoirs in Central Europe.

The impact of dam reservoirs on river ecosystems is one of the current major issues in hydrobiology. In addition to the impact on native biodiversity, impoundments may facilitate biological invasions. A successful invasion is presumably related to the individual life history and resource allocation strategy in expanding populations. We tested whether reservoirs affect the body condition of invasive Faxonius limosus in upland streams. We found positive allometry of growth in females but more frequent isometric growth in males, and the form factor a3.0 was significantly higher in males than in females within populations. Fulton's condition factor (K) was calculated for standard carapace lengths of 20mm (juvenile) and 40mm (adult). Both mean KCL 20 and KCL 40 were higher in males than in females. Positive allometry of growth in females resulted in a larger mean KCL 40 than KCL 20. The majority of the mean K obtained in reservoirs was similar or lower than the respective condition in streams. The condition of adult females was higher in streams in comparison to reservoirs. The obtained results are in contrast to the hypothesis that reservoirs positively affect individual body conditions and show that these man-made lakes do not provide more favourable habitat conditions for F. limosus than those in the natural aquatic environments of an upland landscape. An advantageous effect of the presence of reservoirs on invasion spread may be possible in more ecologically harsh landscapes, especially in colder climatic zones. Our study is the first to investigate the relationship of the body condition of F. limosus in two contrasting habitats.

Genomics Reveals Exceptional Phylogenetic Diversity Within a Narrow-Range Flightless Insect

AbstractRange-restricted upland taxa are prone to population bottlenecks and thus typically have low genetic diversity, making them particularly vulnerable to environmental change. In this study, we used a combination of genotyping-by-sequencing (10,419 SNPs) and mitochondrial COI sequencing to test for population genetic structure within the narrow-range flightless sub-alpine stonefly Zelandoperla maungatuaensis Foster. This species is restricted to only a handful of upland streams along a 4 km stretch of the isolated Maungatua range in southeast New Zealand. We identified striking genetic structure across the narrow range of Z. maungatuaensis, with three deeply divergent allopatric lineages detected. These distinct lineages likely diverged in the early-mid Pleistocene, apparently persisting in separate microrefugia throughout subsequent glacial cycles. Our results illustrate how secondary flight loss can facilitate insect diversification across fine spatial scales, and demonstrate that intraspecific phylogenetic diversity cannot necessarily be predicted from range-size alone. Additional demographic analyses are required to better understand the conservation status of these divergent Z. maungatuaensis lineages, and to assess their potential susceptibility to climate change and other anthropogenic impacts.

Personality, density and habitat drive the dispersal of invasive crayfish

There is increasing evidence that personality traits may drive dispersal patterns of animals, including invasive species. We investigated, using the widespread signal crayfish Pacifastacus leniusculus as a model invasive species, whether effects of personality traits on dispersal were independent of, or affected by, other factors including population density, habitat, crayfish size, sex and limb loss, along an invasion gradient. Behavioural traits (boldness, activity, exploration, willingness to climb) of 310 individually marked signal crayfish were measured at fully-established, newly-established and invasion front sites of two upland streams. After a period at liberty, recaptured crayfish were reassessed for behavioural traits (newly-established, invasion front). Dispersal distance and direction of crayfish movement, local population density, fine-scale habitat characteristics and crayfish size, sex and limb loss were also measured. Individual crayfish exhibited consistency in behavioural traits over time which formed a behavioural syndrome. Dispersal was both positively and negatively affected by personality traits, positively by local population density and negatively by refuge availability. No effect of size, sex and limb loss was recorded. Personality played a role in promoting dispersal but population density and local habitat complexity were also important determinants. Predicting biological invasion in animals is likely to require better integration of these processes.

Hydromorphological Inventory and Evaluation of the Upland Stream: Case Study of a Small Ungauged Catchment in Western Carpathians, Poland

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.

Habitat restoration weakens negative environmental effects on telomere dynamics.

Habitat quality can have far-reaching effects on organismal fitness, an issue of concern given the current scale of habitat degradation. Many temperate upland streams have reduced nutrient levels due to human activity. Nutrient restoration confers benefits in terms of invertebrate food availability and subsequent fish growth rates. Here we test whether these mitigation measures also affect the rate of cellular ageing of the fish, measured in terms of the telomeres that cap the ends of eukaryotic chromosomes. We equally distributed Atlantic salmon eggs from the same 30 focal families into 10 human-impacted oligotrophic streams in northern Scotland. Nutrient levels in five of the streams were restored by simulating the deposition of a small number of adult Atlantic salmon Salmo salar carcasses at the end of the spawning period, while five reference streams were left as controls. Telomere lengths and expression of the telomerase reverse transcriptase (TERT) gene that may act to lengthen telomeres were then measured in the young fish when 15months old. While TERT expression was unrelated to any of the measured variables, telomere lengths were shorter in salmon living at higher densities and in areas with a lower availability of the preferred substrate (cobbles and boulders). However, the adverse effects of these habitat features were much reduced in the streams receiving nutrients. These results suggest that adverse environmental pressures are weakened when nutrients are restored, presumably because the resulting increase in food supply reduces levels of both competition and stress.