Search results for "GIS"
showing 10 items of 7190 documents
Migratory passage structures at hydropower plants as potential physiological and behavioural selective agents
2019
Anthropogenic activities affect fish populations worldwide. River dams have profound impacts on ecosystems by changing habitats and hindering migration. In an effort to counteract such effects, a range of mitigation measures have been installed at hydroelectric power plants. However, not all individuals in a population use these measures, potentially creating strong selection processes at hydroelectric power plants. This may be especially true during migration; fish can get heavily delayed or pass through a hydropower turbine, thus facing increased mortality compared with those using a safe bypass route. In this study, we quantify migration route choices of descending wild passive integrate…
Forty questions of importance to the policy and practice of native oyster reef restoration in Europe
2020
© 2020 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons Ltd Oyster reefs are among the most threatened marine habitats globally. In Europe, oyster reefs have been extirpated from most locations within their historical range. Active restoration of the native oyster (Ostrea edulis) in Europe has grown substantially in recent years. In sharing experiences between oyster restoration projects in Europe at the Native Oyster Restoration Alliance conference, NORA2, in Edinburgh in May 2019, it became apparent that a number of similar barriers are experienced. This study identified the top 40 questions, which, if answered, would have the greatest inf…
Vibration Monitoring of the Mechanical Harvesting of Citrus to Improve Fruit Detachment Efficiency
2019
The introduction of a mechanical harvesting process for oranges can contribute to enhancing farm profitability and reducing labour dependency. The objective of this work is to determine the spread of the vibration in citrus tree canopies to establish recommendations to reach high values of fruit detachment efficiency and eliminate the need for subsequent hand-harvesting processes. Field tests were carried out with a lateral tractor-drawn canopy shaker on four commercial plots of sweet oranges. Canopy vibration during the harvesting process was measured with a set of triaxial accelerometer sensors with a datalogger placed on 90 bearing branches. Monitoring of the vibration process, fruit pro…
Resource polymorphism in European whitefish: Analysis of fatty acid profiles provides more detailed evidence than traditional methods alone
2019
Published version, licensed CC BY-NC-ND 4.0. , available at: http://dx.doi.org/10.1371/journal.pone.0221338 Resource polymorphism—whereby ancestral generalist populations give rise to several specialised morphs along a resource gradient—is common where species colonise newly formed ecosystems. This phenomenon is particularly well documented in freshwater fish populations inhabiting postglacial lakes formed at the end of the last ice age. However, knowledge on how such differential exploitation of resources across contrasting habitats might be reflected in the biochemical compositions of diverging populations is still limited, though such patterns might be expected. Here, we aimed to assess …
Resource Partitioning in Food, Space and Time between Arctic Charr (Salvelinus alpinus), Brown Trout (Salmo trutta) and European Whitefish (Coregonus…
2017
Arctic charr and European whitefish are considered to be strong competitors in lakes, with the latter usually being the superior species. However, high niche plasticity and lake morphometry may suggestively facilitate resource partitioning and coexistence between charr and whitefish. Here, we explore the trophic niche utilization (diet and habitat use) of charr and whitefish co-occurring with brown trout in the deep and oligotrophic Lake Fyresvatnet, southern Norway (59˚05’N, 8˚10’E). Using CPUE, stomach contents and stable isotope analyses, a distinct resource partitioning was revealed between brown trout and the other two species. Brown trout typically occupied the littoral zone, feeding …
From clear lakes to murky waters – tracing the functional response of high-latitude lake communities to concurrent ‘greening’ and ‘browning’
2019
Climate change and the intensification of land use practices are causing widespread eutrophication of subarctic lakes. The implications of this rapid change for lake ecosystem function remain poorly understood. To assess how freshwater communities respond to such profound changes in their habitat and resource availability, we conducted a space-for-time analysis of food-web structure in 30 lakes situated across a temperature-productivity gradient equivalent to the predicted future climate of subarctic Europe (temperature +3 degrees C, precipitation +30% and nutrient +45 mu g L-1 total phosphorus). Along this gradient, we observed an increase in the assimilation of pelagic-derived carbon from…
Medieval Monastery Gardens in Iceland and Norway
2021
Gardening was an important part of the daily duties within several of the religious orders in Europe during the Middle Ages. The rule of Saint Benedict specified that the monastery should, if possible, contain a garden within itself, and before and above all things, special care should be taken of the sick, so that they may be served in very deed, as Christ himself. The cultivation of medicinal and utility plants was important to meet the material needs of the monastic institutions, but no physical garden has yet been found and excavated in either Scandinavia or Iceland. Especially the Cistercians were well known for being pioneer gardeners, but also other orders like the Benedictines and A…
Exposing ecological and economic costs of the research-implementation gap and compromises in decision making
2018
The frequently discussed gap between conservation science and practice is manifest in the gap between spatial conservation prioritization plans and their implementation. We analyzed the research-implementation gap of one zoning case by comparing results of a spatial prioritization analysis aimed at avoiding ecological impact of peat mining in a regional zoning process with the final zoning plan. We examined the relatively complex planning process to determine the gaps among research, zoning, and decision making. We quantified the ecological costs of the differing trade-offs between ecological and socioeconomic factors included in the different zoning suggestions by comparing the landscape-l…
Eight decades of adaptive changes in herring reproductive investment: the joint effect of environment and exploitation
2021
Abstract Reproductive investment is a central trait for population dynamics and productivity. Fishing and environmental variations are major drivers affecting population structure, dynamics, and adaptation of life-history and behavioural traits. However, those factors are often considered independently, and few studies take into account their joint effect. In this study, we investigate the contribution of environment, fishing pressure, and intra-specific competition to variation in the reproductive investment of the Norwegian spring-spawning herring (Clupea harengus), a stock that has been fished for centuries, and monitored for decades. Reproductive investment and post-spawning weight were…
Assessing multiple sources of data to detect illegal fishing, trade and mislabelling of elasmobranchs in Greek markets
2020
Abstract Elasmobranchs, extremely charismatic and threatened animals, still are an important economic source for fishers in many parts of the world, providing significant income through trade. Even though Greek seas host at least 67 elasmobranch species, our knowledge about their biology and ecology is to a large extent unknown. In the present study the integration of conventional (legislation, official data from fisheries landings and fish market value and import/export data) and unconventional (social media) sources of data, accompanied with the use of genetics, aim at outlining the elasmobranch fisheries and trade in Greece and identifying “weak spots” that sabotage their conservation. R…