90 research outputs found

    Identifying key needs for the integration of social‐ecological outcomes in arctic wildlife monitoring

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    For effective monitoring in social‐ecological systems to meet needs for biodiversity, science, and humans, desired outcomes must be clearly defined and routes from direct to derived outcomes understood. The Arctic is undergoing rapid climatic, ecological, social, and economic changes and requires effective wildlife monitoring to meet diverse stakeholder needs. To identify stakeholder priorities concerning desired outcomes of arctic wildlife monitoring, we conducted in‐depth interviews with 29 arctic scientists, policy and decision makers, and representatives of Indigenous organizations and NGOs. Using qualitative content analysis, we identified and defined desired outcomes and documented links between outcomes. Using network analysis, we investigated the structure of perceived links between desired outcomes. We identified 18 desired outcomes from monitoring and classified them as either driven by monitoring information, monitoring process, or a combination of both. Highly cited outcomes were make decisions, conserve, detect change, disseminate, and secure food. These reflect key foci of arctic monitoring. Infrequently cited outcomes (e.g., govern) were emerging themes. Three modules comprised our outcome network. The modularity highlighted the low strength of perceived links between outcomes that were information driven or primarily information driven (e.g., detect change, make decisions, conserve or secure food) and process driven and derived outcomes (e.g., cooperate, learn, educate). The outcomes expand monitoring community and disseminate created connections between these modules. We identified key desired outcomes from monitoring that are widely applicable to social‐ecological systems within and outside the Arctic, particularly those with wildlife subsistence economies. Attributes and motivations associated with outcomes can guide future development of integrated monitoring goals for biodiversity conservation and human needs. Our results demonstrate the disconnect between information and process driven goals and how expanding the monitoring community and better integrating monitoring stakeholders will help connect information derived and process derived outcomes for effective ecosystem stewardship

    Response of small sea ice floes in regular waves: A comparison of numerical and experimental results

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    In severe seas ice floes can gain significant kinetic energy presenting a hazard to offshore structures and shipping. A numerical investigation is presented to investigate the kinematic response of sea ice floes in waves. The results are compared against available experimental data. The surge, heave and drift velocity are analyzed for various different ice floe shapes using the potential flow model HydroSTARÂź and the viscous flow CFD model OpenFOAMÂź. The results show relative wavelength (λ normalized with floe length Lc) λ/Lc strongly influences heave and surge, with a heave resonance occurring at λ/Lc=8 for the cubic floe not being correspondingly observed for the square floe. The heave Response Amplitude Operator (RAO) is found to increase with floe thickness with a resonance occurring when relative thickness b/Lc≄0.5. Shape is observed to be less important than thickness. At small values of λ/Lc the floe is observed to move forward over the whole wavelength resulting in its drift displacement. Both vertical velocity relative to theoretical particle velocity Vy/Vp and ratio of forward and backward velocities show resonance at λ/Lc=8. Comparing with experimental data, the linear analysis using HydroSTARÂź overestimates the heave and surge RAOs. OpenFOAMÂź, however, appears to provide a much better agreement with the experimental data indicating viscosity plays an important role in floe kinematics

    Effect of temperature on rates of ammonium uptake and nitrification in the western coastal Arctic during winter, spring, and summer

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    Biogeochemical rate processes in the Arctic are not currently well constrained, and there is very limited information on how rates may change as the region warms. Here we present data on the sensitivity of ammonium (NH4+) uptake and nitrification rates to short-term warming. Samples were collected from the Chukchi Sea off the coast of Barrow, Alaska, during winter, spring, and summer and incubated for 24h in the dark with additions of (NH4+)-N-15 at -1.5, 6, 13, and 20 degrees C. Rates of NH4+ uptake and nitrification were measured in conjunction with bacterial production. In all seasons, NH4+ uptake rates were highest at temperatures similar to current summertime conditions but dropped off with increased warming, indicative of psychrophilic (i.e., cold-loving) microbial communities. In contrast, nitrification rates were less sensitive to temperature and were higher in winter and spring compared to summer. These findings suggest that as the Arctic coastal ecosystem continues to warm, NH4+ assimilation may become increasingly important, relative to nitrification, although the magnitude of NH4+ assimilation would be still be lower than nitrification

    Demersal Fish Assemblages and Spatial Diversity Patterns in the Arctic-Atlantic Transition Zone in the Barents Sea

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    Direct and indirect effects of global warming are expected to be pronounced and fast in the Arctic, impacting terrestrial, freshwater and marine ecosystems. The Barents Sea is a high latitude shelf Sea and a boundary area between arctic and boreal faunas. These faunas are likely to respond differently to changes in climate. In addition, the Barents Sea is highly impacted by fisheries and other human activities. This strong human presence places great demands on scientific investigation and advisory capacity. In order to identify basic community structures against which future climate related or other human induced changes could be evaluated, we analyzed species composition and diversity of demersal fish in the Barents Sea. We found six main assemblages that were separated along depth and temperature gradients. There are indications that climate driven changes have already taken place, since boreal species were found in large parts of the Barents Sea shelf, including also the northern Arctic area. When modelling diversity as a function of depth and temperature, we found that two of the assemblages in the eastern Barents Sea showed lower diversity than expected from their depth and temperature. This is probably caused by low habitat complexity and the distance to the pool of boreal species in the western Barents Sea. In contrast coastal assemblages in south western Barents Sea and along Novaya Zemlya archipelago in the Eastern Barents Sea can be described as diversity “hotspots”; the South-western area had high density of species, abundance and biomass, and here some species have their northern distribution limit, whereas the Novaya Zemlya area has unique fauna of Arctic, coastal demersal fish. (see Information S1 for abstract in Russian)

    The Arctic freshwater system : changes and impacts

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    Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): G04S54, doi:10.1029/2006JG000353.Dramatic changes have been observed in the Arctic over the last century. Many of these involve the storage and cycling of fresh water. On land, precipitation and river discharge, lake abundance and size, glacier area and volume, soil moisture, and a variety of permafrost characteristics have changed. In the ocean, sea ice thickness and areal coverage have decreased and water mass circulation patterns have shifted, changing freshwater pathways and sea ice cover dynamics. Precipitation onto the ocean surface has also changed. Such changes are expected to continue, and perhaps accelerate, in the coming century, enhanced by complex feedbacks between the oceanic, atmospheric, and terrestrial freshwater systems. Change to the arctic freshwater system heralds changes for our global physical and ecological environment as well as human activities in the Arctic. In this paper we review observed changes in the arctic freshwater system over the last century in terrestrial, atmospheric, and oceanic systems.The authors gratefully acknowledge the National Science Foundation (NSF) for funding this synthesis work. This paper is principally the work of authors funded under the NSF-funded Freshwater Integration (FWI) study
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