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1.
To investigate whether European whitefish (Coregonus lavaretus) groups in the brackish (≤7%) Gulf of Bothnia (Baltic Sea) express specific otolith elemental characteristics, concentrations of elements (Ca, Ba, Sr, Zn, Mn, Fe) in whole otoliths were studied by inductively coupled plasma‐optical emission spectrometry. Whitefish (N = 67) were sampled from six different latitudinal sites; four in the sea and two in rivers along the west coast of Finland, and from a fresh water lake for comparison. The concentration of several elements showed significant differences among sampling sites. Otolith Ba concentrations were higher at the northern sampling sites compared to the southern ones, thereby showing negative association to capture‐habitat salinity. In contrast, otolith Sr and Zn concentrations were lower at the northern sampling sites, thereby associating positively to capture‐habitat salinity. Otolith Mn concentrations did not associate with latitude or salinity but markedly varied between sampling sites. Elevated Fe concentrations occurred in fish otoliths from the two northernmost sites. Ca concentrations were at the same levels in otoliths from all whitefish samples. Otoliths of whitefish from the lake had very high Ba and low Sr concentrations compared to concentrations in otoliths from whitefish in the sea and rivers. Our results show that otolith elemental characteristics of whitefish vary considerably at various geographic scales showing high potential for population identification using elemental fingerprints. Analysis of otolith elemental characteristics may therefore provide an efficient tool for the identification of main areas of residence, spawning locations, and migration routes, thus contributing towards the sustainable management of whitefish stocks.  相似文献   
2.
Biomass limit reference points are widely used in fisheries management and define the biomass threshold (BT) below which stock productivity (i.e. recruitment) is likely to be impaired. Scientifically sound and transparent methods for estimating BTs are therefore needed together with ways of quantifying uncertainties. The main focus of the study was placed on two methods currently applied to several small‐bodied pelagic species in the Northeast Atlantic. These methods have not formerly been described in the scientific literature and are in the present study being compared with some already described methods, of which one is broadly applied outside the Northeast Atlantic. Using a combination of data simulations and data from 51 small‐bodied pelagic fish stocks, we analysed the sensitivity of estimated BTs to (a) the choice of method, (b) time‐series length and (c) stock development (e.g. rebuilding or declining). It was demonstrated that estimated BTs are associated with considerable uncertainty not previously quantified. Furthermore, the level of the estimated threshold and the amount of uncertainty depended on choice of method, time‐series length and stock development trends. Hence, this study contributes to improving the quality of future biomass limit reference points by providing guidance regarding choice of method and how to demonstrate stock‐specific uncertainties.  相似文献   
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4.
In just two decades, round goby Neogobius melanostomus (Pallas) has dispersed throughout most of the Baltic and the North American Great Lakes. It thrives in shallow sheltered areas, where it is impacting native fauna. In Denmark, researchers, governmental institutions and fishers have joined in an effort to establish a sustainable round goby fishery. To do so, basic information about the movement of round goby is essential, so the movements of 50 round gobies were tracked using acoustic telemetry. The results revealed that activity took place mainly at night and seasonal migrations were common. The most frequent migration behaviour observed was a seaward return migration during winter, which was further confirmed by a snorkel survey. Tracking data also revealed riverine upstream dispersal. The results demonstrate that the round goby can be mapped using telemetry, and it is suggested that fishing for round goby may improve efficiency by targeting seasonal migration corridors.  相似文献   
5.
Abstract – Fish, which are generally visual foragers, experiences reduced reaction distance in visually degraded environments, which has consequences for encounter rates with prey. Small prey is detected at shorter distances than larger prey, and piscivores are therefore predicted to be more strongly affected by visual degradation. In experiments, roach (Rutilus rutilus) were fed two plankton prey types and pike (Esox lucius) were fed Daphnia and larval roach, in clear water, algal turbid water and water coloured brown by dissolved organic matter (DOM). Planktivorous foraging in roach was not affected by visual degradation, while pike foraging on both Daphnia and larval roach was. Pike showed increased reaction distance to Daphnia in visually degraded water, while it was severely reduced with roach as prey even if the visual range was not reduced below pike reaction distances in clear water. Pike foraging on Daphnia was not affected, but when foraging on roach, the reduced search efficiency was counteracted by increased attack rates. However, there was no increase in movement and no difference between turbid and DOM treatments. Effects on piscivores will likely become more pronounced at later life stages as prey size and the reliance on long‐distance detection increases at the same time as changing climatic conditions may further deteriorate the visual conditions in future.  相似文献   
6.
Several selective androgen receptor modulators (SARMs) have been synthesized and investigated in humans, rats, and dogs in the past, but no data are yet available concerning the metabolism of SARMs in horses. The aryl-propionamide-derived drug candidates S24 and S4 (andarine) have a strong androgen receptor binding affinity and show distinctive specific cell answers. Although no SARM drug candidate (aiming for testosterone replacement therapy) has completed clinical trials yet, S4 has been illicitly available via the Internet. These facts led to the prohibition of SARMs by the German equestrian federation, and the (mis)use of such compounds would further represent a doping rule violation in horse racing. In this study, the drug candidates S24 and S4 were subjected to in vitro metabolism experiments with equine liver microsomal preparations from a female Quarter Horse to obtain information about potential target analytes in equine doping control analysis. The enzymatically synthesized metabolites were characterized by liquid chromatography–tandem mass spectrometry and –high-resolution/high-accuracy mass spectrometry. All observed S24 and S4 equine metabolites are in agreement with earlier in vitro and in vivo studies in humans and dogs. Nevertheless, the relative percentage of generated equine metabolites (as determined from the analytes’ response in full-scan chromatography–tandem mass spectrometry and –high-resolution/high-accuracy mass spectrometry measurements) differs considerably from the reported profiles. Although the S24 metabolite pattern is comparably balanced concerning glucuronidated and sulfonated conjugates, the major S4 metabolite was found to be the unconjugated dephenylated compound, with a proportion of more than 90%.  相似文献   
7.
Borna disease virus (BDV) is a RNA-virus causing neurological disorders in a wide range of mammals. In cats, BDV infection may cause staggering disease. Presently, staggering disease is a tentative clinical diagnosis, only confirmed at necropsy. In this study, cats with staggering disease were investigated to study markers of BDV infection aiming for improvement of current diagnostics. Nineteen cats fulfilled the inclusion criteria based on neurological signs and pathological findings. In 17/19 cats, BDV infection markers (BDV-specific antibodies and/or BDV-RNA) were found, and antibodies in serum (13/16, 81%) were the most common marker. BDV-RNA was found in 11/19 cats (58%). In a reference population without neurological signs, 4/25 cats were seropositive (16%). The clinical history and neurological signs in combination with presence of BDV infection markers, where serology and rRT-PCR on blood can be helpful tools, improve the diagnostic accuracy in the living cat.  相似文献   
8.
The forest-based sector has been at the forefront in operationally implementing the sustainability concept, its associated principles and indicators for sustainable forest management. Several methods have been developed to study environmental impacts of forestry activities, but none of the existing tools address all the dimensions of sustainability along the whole forest wood chain (FWC) in a balanced way. Consequently, the decision was made to develop a tool for sustainability impact assessment (ToSIA), the modelling framework for sustainability impact assessment of FWCs. The objective of the EU Project Eforwood was to develop ToSIA, a decision support tool. Within ToSIA, a FWC is modelled as a number of interconnected processes. For each process, a range of economic, environmental and social indicators and their respective values are calculated, thus representing the three pillars of sustainability. By this method, the multifunctionality of forests can be assessed and supply chains can be compared with respect to sustainability. Sensitivity analysis and scenario techniques can be applied to learn about the effect of expected changes to the structure of the chain, the material flows and the indicator values. In order to provide the tool with information about forest and logging operations, data were collected at two fundamental levels: (1) a regional level with case studies in Scandinavia, Iberia and Baden-Württemberg and (2) a European level with a case study that reflects conditions in the 27 countries of the European Union. This paper describes and details the harvesting and logging processes for the European countries. The results are displayed for each of the three regional case studies as well as aggregated to five principal areas in Europe: Eastern, Northern, Western, Central and Southwest Europe.  相似文献   
9.
Greywater is a potential resource of water that can be improved to meet the quality needed for irrigation. This study evaluated the performance of bark, activated charcoal, polyurethane foam and sand filters in removing biochemical oxygen demand (BOD5), surfactants, phosphorus, nitrogen and microbial indicators from greywater during start-up and steady state. In column experiments, 0.6?m high filters (diameter 20?cm) were fed for 113?days with artificial greywater at a hydraulic loading rate of 0.032?m3?m?2?day?1 and an organic loading rate of 0.014?kg BOD5 m?2?day?1. Bark and activated charcoal efficiently reduced the concentrations of organics (BOD5), surfactants (methylene blue active substances??MBAS), total phosphorus (Tot-P) and total thermotolerant coliform numbers, while sand and foam were less efficient. Bark, activated charcoal, foam and sand reduced influent BOD5 by 98, 97, 37 and 75?%; MBAS by >99, >99, 73 and 96?%; Tot-P by 97, 91, 36 and 78?%; and total nitrogen by 19, 98, 13 and 5?%, respectively. BOD5 and MBAS were efficiently reduced directly from start-up by bark and activated charcoal, while foam needed 30?days to achieve about 50?% reduction in BOD5. Bark was the most efficient filter in reducing thermotolerant faecal coliforms (2.4 log10), while foam achieved the lowest reduction (0.5 log10). Overall, bark and activated charcoal filters appeared to be the most suitable filters for improving greywater quality to reach irrigation quality in terms of organic matter reduction. Performance of these filters under higher and fluctuating loadings and the long-term sustainability of the filter materials need further investigation.  相似文献   
10.
We identify, describe qualitatively, quantify biophysically and, if possible, monetarily valuate the most important ecosystem services in Swedish forests. Existing Swedish and Nordic research and statistics within this area are reviewed and used to develop a first framework for the valuation of ecosystem services in Swedish forests. We base our analysis on the CICES framework and the Cascade-model. Despite the rather long occurrence and use of the concept of ecosystem services, we do not yet have enough information on the status and economic value of services in Swedish forests. The value of the forest ecosystem services is at best an indication of the different multifunctional objectives that should be met in the management of the Swedish forests. The five most central ecosystem services in Swedish forests according to annual flow are timber and pulpwood, bioenergy, game, climate regulation and recreation and training, each estimated to have a monetary value of several billion SEK. The different ecosystem services in multipurpose forests interact with each other and may lead to conflicts between use and conservation. We identified a number of trade-offs and synergies between services focusing on the five above ecosystem services.  相似文献   
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