scholarly journals Dispersal of invasive species by drifting

2011 ◽  
Vol 57 (6) ◽  
pp. 818-827 ◽  
Author(s):  
M.C. Van Riel ◽  
G. Van Der Velde ◽  
A. Bij De Vaate
Keyword(s):  
Invasive Species ◽  
Water Column ◽  
Aquatic Organisms ◽  
Aquatic Macroinvertebrates ◽  
Winter Period ◽  
River Rhine ◽  
Summer Period ◽  
Diel Patterns ◽  
Dispersal Mechanism ◽  
Dispersal Vectors

Abstract Drifting can be an effective way for aquatic organisms to disperse and colonise new areas. Increasing connectivity between European large rivers facilitates invasion by drifting aquatic macroinvertebrates. The present study shows that high abundances of invasive species drift in the headstream of the river Rhine. Dikerogammarus villosus and Chelicorophium curvispinum represented up to 90% of the total of drifting macroinvertebrates. Drift activity shows seasonal and diel patterns. Most species started drifting in spring and were most abundant in the water column during the summer period. Drift activity was very low during the winter period. Diel patterns were apparent; most species, including D. villosus, drifted during the night. Drifting macroinvertebrates colonised stony substrate directly from the water column. D. villosus generally colonised the substrate at night, while higher numbers of C. curvispinum colonised the substrate during the day. It is very likely that drifting functions as a dispersal mechanism for crustacean invaders. Once waterways are connected, these species are no longer necessarily dependent on dispersal vectors other than drift for extending their distribution range.

Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance

2010 ◽  
Vol 45 (4) ◽  
pp. 451-461 ◽  
Author(s):  
Nandana Perera ◽  
Bahram Gharabaghi ◽  
Peter Noehammer ◽  
Bruce Kilgour
Keyword(s):  
Mass Balance ◽  
Management Practices ◽  
Chloride Concentration ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Road Salt ◽  
Winter Period ◽  
Chloride Mass Balance ◽  
Creek Watershed ◽  
Chloride Concentrations

Abstract Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.

scholarly journals An Efficient Prediction Model for Water Discharge in Schoharie Creek, NY

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Katerina G. Tsakiri ◽  
Antonios E. Marsellos ◽  
Igor G. Zurbenko
Keyword(s):  
New York ◽  
Time Series ◽  
Water Discharge ◽  
Winter Period ◽  
Statistical Methodology ◽  
Summer Period ◽  
Short Term ◽  
Efficient Prediction ◽  
Climatic Time Series

Flooding normally occurs during periods of excessive precipitation or thawing in the winter period (ice jam). Flooding is typically accompanied by an increase in river discharge. This paper presents a statistical model for the prediction and explanation of the water discharge time series using an example from the Schoharie Creek, New York (one of the principal tributaries of the Mohawk River). It is developed with a view to wider application in similar water basins. In this study a statistical methodology for the decomposition of the time series is used. The Kolmogorov-Zurbenko filter is used for the decomposition of the hydrological and climatic time series into the seasonal and the long and the short term component. We analyze the time series of the water discharge by using a summer and a winter model. The explanation of the water discharge has been improved up to 81%. The results show that as water discharge increases in the long term then the water table replenishes, and in the seasonal term it depletes. In the short term, the groundwater drops during the winter period, and it rises during the summer period. This methodology can be applied for the prediction of the water discharge at multiple sites.

1.  Toxicity of Fresh and Weathered Sunken Heavy Fuel Oil to the Early Life Stages of Rainbow Trout (Oncorhynchus mykiss) in Simulated Spawning Shoal Environments

2016 ◽  
Author(s):  
Julie Adams
Keyword(s):  
Rainbow Trout ◽  
Water Column ◽  
Aquatic Organisms ◽  
Fuel Oil ◽  
South American ◽  
Benthic Organisms ◽  
Heavy Fuel Oil ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Direct Exposure ◽  
Insight Into

Because the density of heavy fuel oil (HFO) is equal to or greater than that of freshwater, it behaves differently than lighter oils that float. Heavy fuel oil can sink to the bottom or be suspended in the water column and affect aquatic organisms that are not typically exposed to floating oils. Most research on oil spill technologies thus far examines the direct exposure of rainbow trout to floating or submerged oil droplets; there is little knowledge of the impacts of non‐floating heavy fuel oil on the water column and benthic organisms exposed to oil that accumulates in sediments. The toxicity of sunken HFO 6303 and Medium South American (MESA; reference) crude oil, as well as the effects of weathering on toxicity to embryos of rainbow trout were assessed using increasing concentrations of oil on gravel substrate in continuous‐flow desorption columns. Toxicity was assessed by measurement of the rates of mortality and growth, and the prevalence of blue sac disease, a hallmark sign of oil toxicity. The lower median lethal concentration for HFO compared to MESA indicated that HFO is more toxic. Interestingly, the LC50 values for fresh and weathered for both oils were similar, indicating little change in toxicity when the oil weathers naturally. Repetition of this experiment and analysis of PAH content in each treatment will provide more insight into the environmental and health risks associated with sunken heavy fuel oil.   

scholarly journals Characteristics and Seasonal Variations of Atmospheric Deposition of Selected Elements in the Urban and Industrial Environment of Košice (Slovakia)

2021 ◽  
Vol 906 (1) ◽  
pp. 012100
Author(s):  
Jozef Hančul’ák ◽  
Ol’ga Šestinová ◽  
Lenka Findoráková
Keyword(s):  
Atmospheric Deposition ◽  
Detailed Analysis ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Water Soluble ◽  
Dust Particles ◽  
Winter Period ◽  
Emission Sources ◽  
Summer Period ◽  
The Impact

Abstract This study aims to evaluate the impact of local emission sources on the environmental load through a detailed analysis of the atmospheric deposition (AD). The main sources of pollution are neighbouring iron and steelworks and typical urban sources, such as the heating plant, transport, construction, etc. Total atmospheric deposition, i.e. both wet and dry ones, were sampled from eleven sampling sites that have been placed on the roofs above the height of the surrounding buildings at a distance of 1 to 16 kilometers from the main source of pollution in the urban, suburban and rural areas. The atmospheric deposition fluxes of selected elements (Fe, Al, Mn, Zn, Pb, Cu, Cr, Cd, As) were determined separately for “water-soluble” and “insoluble phase” (particulate matter - PM) as well as in terms of the heating season for summer and winter half-year. The results from 2009–2020 are introduced. The average Fe deposition at urban stations in Košice was 2-3 times higher, compared with other urban areas. The very high values of iron deposition (9,181) and manganese (348 mg.m-2.yr-1) were measured mainly at sites near the ironworks. The highest values of correlation coefficients were calculated by Pearson correlation analysis for the elements Fe, Mn and Cr but also for Al and PM. Higher values of correlation coefficients were calculated for the winter period. The monitored elements are bound to the insoluble component AD in the order of Fe, Al, Cr, Pb, Mn and As. Cadmium and zinc are preferably bound to the soluble phase for sites north of the ironworks. Significant differences for fluxes of AD of the most observed parameters were found between the summer and winter periods. In winter, higher values of AD were found for the elements Fe, Pb, Mn, Cr, and Cd. In the case of zinc and arsenic higher values were recorded in the summer period. The share of emission sources of iron and steelworks on the fluxes of iron at the urban sites in winter was more than doubled compared to the summer period. The smallest seasonal differences for all observed components were found at localities near the ironworks. Detailed analysis of AD showed that in addition to Fe, Mn, and Cr, the ironworks complex is also a source of dust particles, aluminum and other observed elements in descending order of lead, zinc, copper, arsenic and cadmium.

Effect of temperature and relative humidity on the milk production of dairy cows

2021 ◽  
Vol 13 (2) ◽  
pp. 22-27
Author(s):  
Ivan Imrich ◽  
Róbert Toman ◽  
Martina Pšenková ◽  
Eva Mlyneková ◽  
Tomáš Kanka ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Effect Of Temperature ◽  
Winter Period ◽  
Summer Period ◽  
Average Temperature ◽  
Holstein Friesian ◽  
Humidity Index ◽  
Index Value

The aim of this study was to evaluate the influence of environmental housing conditions on the milk yield of dairy cows. Measurements were taken in the summer period from June to September 2020 and in the winter period during January 2021 on a large-capacity farm of Holstein Friesian cattle. Cows were housed in free stall barn with the lying boxes and selected during the second or third lactations, in the summer period from the 51st day to the 135th day and in the winter period from the 64th day to the 120th day of lactation. The average temperature in the housing was 23 °C in summer, and 7.05 °C in winter. The average THI (thermal humidity index) value in summer was 70.43, but during the day the THI values sometimes reached 75. The dairy cows were therefore exposed to heat stress during summer. Increasing THI and temperature values negatively affected the milk yield, as there was a negative correlation between both THI and milk yield (r = -0.641; p <0.01) and temperature and milk yield (r = -0.637; p <0.01). Milk production in winter was at 58.77 kg per day and in summer at 49.55 kg per day. In the summer, the milk had a significantly lower content of fat (p <0.05), proteins (p <0.001), lactose (p <0.001), minerals (p <0.001) and conversely, a higher number of somatic cells (p <0.01). These results show that worse environmental conditions during the summer negatively affected the level of milk yield and the composition of the cows’ milk.

scholarly journals Design and monitoring of energy-active facade module

2020 ◽  
Vol 172 ◽  
pp. 24005
Author(s):  
Nikola Pokorny ◽  
Tomas Matuska ◽  
Vladimir Jirka ◽  
Borivoj Sourek
Keyword(s):  
Central Europe ◽  
Climatic Conditions ◽  
Solar Irradiation ◽  
Winter Period ◽  
Summer Period ◽  
Beam Radiation ◽  
Potential Benefits ◽  
Long Term Monitoring ◽  
Term Monitoring

Testing of two facade modules under outdoor climatic conditions of Central Europe has been performed for more than two years. The paper analyses the results of long-term monitoring and shows potential benefits of prismatic glazing and photovoltaic-thermal (PVT) collectors integrated into one component. The prismatic glazing reflects beam radiation during summer period and transmits it during the winter period. During summer month solar irradiation transmitted through the prismatic glazing can be about 44 % lower compared to conventional triple glazing. Glazed PVT collector generates heat and electricity simultaneously. PVT collector integrated in the façade module can achieve solar yield during summer 58 kWh/m2.month in heat and 6,3 kWh/m2.month in electricity.

Do power line rights-of-way facilitate the spread of non-peatland and invasive plants in bogs and fens?

Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Caroline Dubé ◽  
Stéphanie Pellerin ◽  
Monique Poulin
Keyword(s):  
Invasive Species ◽  
Invasive Plants ◽  
Power Line ◽  
Water Conductivity ◽  
Abiotic Conditions ◽  
Dispersal Vectors ◽  
Ombrotrophic Bog ◽  
Water Ph ◽  
Linear Infrastructures

Linear infrastructures are known to facilitate the spread of undesirable species in ecosystems. Compared with other types of infrastructure, the role of power line rights-of-way (ROWs) as dispersal vectors remains poorly understood, especially with regard to peatlands. The aim of our study was to evaluate their impacts on the vegetation of ombrotrophic (bog) and minerotrophic (fen) peatlands. The vegetation communities within and adjacent to power line ROWs were sampled in 23 bogs and 11 fens in southern Québec. In fens, invasive species were found in abundance along the first 250 m within ROWs, while native non-peatland species were able to spread into entire ROWs. Invasive species were also able to colonize the adjacent fen habitats but were mostly concentrated in the first 4 m from ROW edges. Some species were, however, able to establish at more than 43 m from ROWs. Invasive and native non-peatland species were mostly restricted to the first 31 m within ROWs intersecting a bog and almost none dispersed in the adjacent bog habitats. Overall, the average cover of native non-peatland and invasive species in ROWs was mostly related to intrinsic abiotic conditions such as water pH, water conductivity, and water table level, while landscape surrounding the peatland and historical variables (e.g., time elapse since the construction of the ROW) had few impacts in both bogs and fens.

scholarly journals The Halloween effect on the agricultural commodities markets

2017 ◽  
Vol 63 (No. 10) ◽  
pp. 441-448 ◽  
Author(s):  
Arendas Peter
Keyword(s):  
Financial Markets ◽  
Asset Returns ◽  
Winter Period ◽  
Agricultural Commodities ◽  
Summer Period ◽  
Price Series ◽  
Time Period ◽  
Halloween Effect ◽  
Commodities Markets

The financial markets are impacted by various seasonal anomalies. One of the best known of them is the Halloween effect. The Halloween effect means that the summer period (May–October) asset returns are lower compared to the winter period (November–April) asset returns. In the paper, price series of 20 major agricultural commodities over the 1980–2015-time period are tested for the presence of the Halloween effect. The data show that 15 out of the 20 commodities recorded a higher average winter period than summer period returns and in 10 cases, the differences are statistically significant. The data also show that out of the 5 commodities with higher summer period returns, only in the case of poultry the differences are statistically significant.  

Low Energy Source Synthetic Thermal Energy Storage (STES)

2014 ◽  
Vol 899 ◽  
pp. 143-146 ◽  
Author(s):  
Veronika Sipkova ◽  
Jiri Labudek ◽  
Otakar Galas
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Performance ◽  
Recycled Concrete ◽  
Winter Period ◽  
Summer Period ◽  
Energy Performance Of Buildings ◽  
Family House

The team of Building environment in VŠB-Technical university of Ostrava works intensively on options in long-term accumulation of heat in underground storages. The new concept follows the Directive of the European Parliament and of the Council 2010/31/EU on the energy performance of buildings [1]. The Directive requires that energy should be extensively covered of renewable sources produced at or in the vicinity of building, where it will be consumed. The aim of the research is create thermal energy storage with model structure for complex of family house. For the storage will be used recycled materials especially recycled concrete. This system will be heat source in winter period and heat consumer in summer period.

Dynamics of Selenium in Mercury-Contaminated Experimental Freshwater Ecosystems

1980 ◽  
Vol 37 (5) ◽  
pp. 848-857 ◽  
Author(s):  
John W. M. Rudd ◽  
Michael A. Turner ◽  
Bruce E. Townsend ◽  
Alison Swick ◽  
Akira Furutani
Keyword(s):  
Water Column ◽  
Aquatic Organisms ◽  
Selenium Concentration ◽  
Freshwater Ecosystems ◽  
Aquatic Herbicides ◽  
Mercury Bioaccumulation ◽  
Simultaneous Movement ◽  
Experimental Treatments ◽  
Aquatic Herbicide ◽  
Rate Of Movement

The simultaneous movement of radiolabeled selenium and mercury was followed in experimental aquatic ecosystems ([Formula: see text] tube enclosures) set into a mercury-contaminated lake. The experimental treatments consisted of increasing stable selenium or sulfate water concentrations, addition of an aquatic herbicide, and isolation of a portion of the water column from contact with sediments. Selenium and mercury did not move together through the ecosystems either geochemically or biologically. Selenium bioaccumulation was rapid by fish, crayfish, and haptobenthos and was enhanced by increased sulfate concentration and in the absence of exposure to bottom sediments. It was reduced in the presence of aquatic herbicides. A selenium concentration of 0.1 mg/L did not affect the rate of movement of mercury out of the water column but it did stabilize the movement of mercury among various compartments in the water column. Elevated selenium appeared to retard the rate of mercury bioaccumulation by fish, crayfish, and haptobenthos. Preliminary observations of selenium toxicity to several aquatic organisms were carried out. The possibility of using selenium as an ameliorating agent for heavy metal polluted freshwater systems is discussed.Key words: selenium, mercury, methylmercury, fish, crayfish

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