64 research outputs found

    Validation of pop-up satellite archival tags (PSATs) on Atlantic cod (Gadus morhua) in a Greenland fjord

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    Traditional tagging techniques are simple and cost-effective, but inferences require recaptures and data on movement/migration are limited to a start and end position at unpredictable intervals. Pop-up satellite archival tags (PSATs) offer other opportunities, as they provide positions at pre-programmed times and collect on-route data, which can be used to describe position, behavior, and habitat preferences. Species suitability should, however, be documented prior to large-scale studies using PSATs. We deployed PSATs on six relatively large (total length 84–125 cm) Atlantic cod (Gadus morhua) in inshore West Greenland waters. Three tags were physically recovered, providing high-resolution data on depth and temperature (readings every 3 s), while three tags did not report (recovery rate = 50 %). To evaluate the tag’s applicability on Atlantic cod, we made a detailed behavioral analysis by defining swimming behavior, occupied water types and depth phases, which were cross-evaluated in relation to depth, temperature and water stratification to identify behavioral patterns. Distinct and shared patterns in swimming behavior were evident and we found no signs of impaired swimming behavior except for an adaptation period lasting up to 39 h after release. Generally, the three cod were pelagic and preferred waters ranging 2–5 °C. When encountering colder water masses these were avoided. During late summer/early autumn, increased vertical activity could in some cases be linked to darkness and a high-activity event could be linked to possible predator avoidance. All combined, we conclude that PSATs are suitable to monitor natural behavior on large specimens of Atlantic cod for periods of at least four months.publishedVersio

    Sub-daily rainfall extremes in the Nordic–Baltic region

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    Short-duration rainfall extremes are associated with a range of societal hazards, notably pluvial flooding but in addition, e.g., erosion-driven nutrient transport and point-source contamination. Fundamental for all analysis, modelling and risk assessment related to short-duration rainfall extremes is the access to and analysis of high-resolution observations. In this study, sub-daily rainfall observations from 543 meteorological stations in the Nordic–Baltic region were collected, quality-controlled and consistently analyzed in terms of records, return levels, geographical and climatic dependencies, time of occurrence of maxima and trends. The results reflect the highly heterogeneous rainfall climate in the region, with longitudinal and latitudinal gradients as well as local variability, and overall agree with previous national investigations. Trend analyses in Norway and Denmark indicated predominantly positive trends in the period 1980–2018, in line with previous investigations. Gridded data sets with estimated return levels and dates of occurrence (of annual maxima) are provided open access. We encourage further efforts towards international exchange of sub-daily rainfall observations as well as consistent regional analyses in order to attain the best possible knowledge on which rainfall extremes are to be expected in present as well as future climates

    Why do poor countries make simple products?

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    The products produced in rich countries are very different from the products produced in poor countries. Why? Unreliable electricity is often cited as one of the main challenges facing industrial production in less developed economies. In this paper, I connect these two observations by linking interruptions in the production environment to the sophistication of the production output. Using a data set covering more than 500,000 observations of manufacturing plants in India between 2000 and 2016, I find evidence suggesting that the level of interruption, modeled here using electricity shortages, contained in a plant's input supply is strongly associated with whether or not more complex products have a positive relationship with plant revenues. This suggests a new pathway between the production environment at the local level and the aggregate complexity of the economy

    Test of light emitting diodes (LED) as a possible bycatch mitigation measure in a gillnet fishery

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    Substantial seabird bycatch occurs in North Atlantic lumpfish fisheries, potentially impacting seabird populations and raising concerns about the fisheries’ sustainability. Despite increased efforts to address this issue, existing approaches have yielded inconclusive and mixed results. In this study, we explored an alternative approach by comparing bycatch levels between conventional gillnets and LED-illuminated gillnets during the 2023 Greenland lumpfish fishing season. Results indicated that LED-illuminated nets showed almost no difference in bycatch compared to no-LED nets for the three main bird species (common eider, king eider, and long-tailed duck), with no statistically significant differences observed. Additionally, the LED-illuminated nets exhibited a slightly lower, but insignificant, catch rate of the targeted female lumpfish. In conclusion, our findings suggest that using LED as a bird deterrent in this fishery is not an optimal solution to bycatch mitigation
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