21 research outputs found

    Context-dependent changes in maritime traffic activity during the first year of the COVID-19 pandemic

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    This article is a contribution of the COVID-19 Bio-Logging Initiative, which is funded in part by the Gordon and Betty Moore Foundation (GBMF9881) and the National Geographic Society (NGS-82515R-20) (both grants to C.R.), and endorsed by the United Nations Decade of Ocean Science for Sustainable Development. Specifically, A.L.’s, R.P.’s and B.R.’s postdoctoral positions were funded by the Gordon and Betty Moore Foundation (GBMF9881), and J.S.’s contributions were funded by the National Geographic Society (NGS-82515R-20). D.W.S. was supported by a Marine Biological Association Senior Research Fellowship with additional support from the Natural Environment Research Council (Discovery Science NE/R00997/X/1) and the European Research Council (Advanced Grant 883583 OCEAN DEOXYFISH).Rapid implementation of human mobility restrictions during the COVID-19 pandemic dramatically reduced maritime activity in early 2020. But where and when activity rebounded, or remained low, during the full extent of 2020 restrictions remains unclear. Using global high-resolution datasets, we reveal a surprising degree of complexity in maritime activity patterns during 2020, yielding a more nuanced picture of how restrictions affected activity. Overall, shipping activity in Exclusive Economic Zones decreased (1.35 %), as expected, however high-seas activity increased (0.28 %). While these annual changes appear modest, there were striking spatially and temporally asynchronous variations in different vessel types’ activity in the second half of 2020, ranging from an > 80 % sustained reduction in passenger vessel activity to a 150 % increase in fishing activity. Results suggest systems-level responses were highly context-dependent, pinpointing areas that experienced significant reductions and spikes in activity, and providing hitherto missing details of COVID-19 impacts on economic and environmental sustainability.Publisher PDFPeer reviewe

    Success Factors of European Syndromic Surveillance Systems: A Worked Example of Applying Qualitative Comparative Analysis

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    Introduction: Syndromic surveillance aims at augmenting traditional public health surveillance with timely information. To gain a head start, it mainly analyses existing data such as from web searches or patient records. Despite the setup of many syndromic surveillance systems, there is still much doubt about the benefit of the approach. There are diverse interactions between performance indicators such as timeliness and various system characteristics. This makes the performance assessment of syndromic surveillance systems a complex endeavour. We assessed if the comparison of several syndromic surveillance systems through Qualitative Comparative Analysis helps to evaluate performance and identify key success factors. Materials and Methods: We compiled case-based, mixed data on performance and characteristics of 19 syndromic surveillance systems in Europe from scientific and grey literature and from site visits. We identified success factors by applying crisp-set Qualitative Comparative Analysis. We focused on two main areas of syndromic surveillance application: seasonal influenza surveillance and situational awareness during different types of potentially health threatening events. Results: We found that syndromic surveillance systems might detect the onset or peak of seasonal influenza earlier if they analyse non-clinical data sources. Timely situational awareness during different types of events is supported by an automated syndromic surveillance system capable of analysing multiple syndromes. To our surprise, the analysis of multiple data sources was no key success factor for situational awareness. Conclusions: We suggest to consider these key success factors when designing or further developing syndromic surveillance systems. Qualitative Comparative Analysis helped interpreting complex, mixed data on small-N cases and resulted in concrete and practically relevant findings

    Evaluation of the addition of in-cage hiding structures and toys and timing of administration of behavioral assessments with newly relinquished shelter cats

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    Most cats entering shelters are euthanized. This study used behavioral assessments to determine how quickly a cat acclimated to its new environment and whether enrichment eased this transition. Twenty-five cats at 2 municipal shelters were evaluated with 2 separate standardized behavioral assessments at 3separate times, beginning the day after entering the shelter. One behavioral assessment included an in-cage evaluation, whereas the other assessment involved a stepwise combined in- and out-of-cage evaluation. Eleven of the cats were given a cardboard box to hide in and a toy in the cage, whereas 14cats were not given these objects. Our results suggest that cats need 72hours to achieve optimum behavioral scores and a decrease in stress levels based on the 2 separate evaluations. The tests were correlated in their outcomes. © 2013 Elsevier Inc

    What Drives Jellyfish Population Cycles? Influence of Climate and Environment on the Complex Life Histories of Scyphozoans

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    Jellyfish population cycles and bloom events occur at global, regional, and local scales. Understanding what causes these cycles now and in the future is a major question in jellyfish bloom research, because of the potential impacts on ecosystem function and services. Most bloom forming scyphozoan jellyfish have complex life histories involving a long-lived asexually reproducing benthic polyp and a sexually reproducing pelagic medusae. Environmental and climate factors affect each life stage, but we do not fully understand how these variables drive life stage transition, or how demographic differences in survival, growth and fecundity translate into visible jellyfish outbreaks. We undertook a comprehensive laboratory and field-based study of the physicochemical conditions that control survival, fecundity and phase transition of the different life stages of scyphozoan jellyfish. Through this research, we examine the effects of environmental drivers on jellyfish population cycles and life stage transition. Modifications to estuaries through the construction of barrages alter the natural dynamics of inhabitant species by controlling freshwater inputs into those systems, driving the presence and absence of medusae from estuaries. As well as this, we explore how environmental conditions translate into reproductive success or failure in temperate populations from the medusa to the polyp life stage, demonstrating that early polyp growth rates are strongly linked to their thermal environment and highlighting a potential marine heatwave event. We examine not only the effects of temperature and other climate drivers on scyphozoan jellyfish growth, survival and reproduction, but also whether epigenetic transgenerational effects can drive acclimation to warmer summer temperatures in the short term in the context of a warming ocean. No parental effects were observed in the first or second generation, and in the third generation the transgenerational effects of temperature were subtle and appeared most strongly in cooling scenarios. Finally, within the setting of anthropogenically-driven climate change, we demonstrate for the first time that A. aurita polyps require a minimum period of cooler temperatures to strobilate, contradicting claims that jellyfish populations will be more prevalent in warming oceans, specifically in the context of warmer winter conditions. To answer these questions, we chose the common, or moon jellyfish Aurelia aurita as our primary experimental organism. However, we expanded our research to other species to demonstrate how they may vary in both environment and response to forcing factors as compared to a ‘typical’ model species. This thesis highlights the importance of examining each population within the context of their environment, and advances our understanding of how the climate and environment affect jellyfish life stage transition

    Transgenerational effects influence acclimation to varying temperatures in <i>Aurelia aurita</i> polyps (Cnidaria: Scyphozoa)

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    Temperature is one of the most important drivers to affect marine ectotherms in the context of anthropogenic climate change modifying seasonal cycles in temperate regions. To reliably predict the impact of climate variability on marine ectotherms, their capacity to adapt to rapid change needs to be understood. Due to fast transmission between generations, transgenerational effects may enable populations to moderate stressors. We examined reproduction across three temperature scenarios and three generations of asexual Aurelia aurita polyps: transgenerational warming, transgenerational cooling, and stable temperatures. Polyps were incubated at three temperatures (15, 17, 19°C) encountered in summertime in Southampton Water. In the first two polyps generations, temperature remained the main driver of polyp reproduction. However, in the third generation parental and grandparental temperature influenced offspring production. These effects appeared most strongly in cooling scenarios: polyps who experienced rapid cooling between generations displayed an immediate drop in reproductive output as opposed to polyps who remained at the same temperature as their parents. Our results highlight that transgenerational effects may require more extreme temperatures or increased numbers of generations to have a measurable impact on a population, highlighting the vulnerability of these organisms to continued climate change

    Transgenerational acclimation influences asexual reproduction in Aurelia aurita jellyfish polyps in response to temperature.: Transgenerational plasticity in polyp reproduction

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    Climate change events and anthropogenic activities (e.g. translocation of nonindigenous species) have been proposed to account for the rise of jellyfish blooms in coastal environments. Bloom-forming scyphozoan jellyfish of the genus Aurelia have successfully invaded new habitats and have caused damaging blooms. In attempting to understand the underlying reasons for their success, researchers have investigated immediate effects of changing environmental conditions (e.g. temperature) on scyphistomae of single/unknown generations, with a particular focus on asexual reproduction. However, it remains unclear how scyphistomae respond to changing conditions over longer time-scales or across generations, and how those responses influence bloom occurrence. Here, we examined the role of transgenerational acclimation in asexual reproduction of A. aurita scyphistomae in a 72 d orthogonal experiment, combining 3 parental with 3 offspring temperatures of 8, 12 and 16°C. The null hypothesis was that the thermal history of the parental (F0) generation will not affect asexual reproduction in the offspring (F1) generation. Our results indicated that, provided with a transgenerational temperature change, parent scyphistomae do modify the reproductive output and timing of offspring. Scyphistomae from 'cold' (8°C) parents displayed the greatest reproductive output (2.86 buds per scyphistoma) and earliest budding commencement (23.86 d) at warm temperature (16°C). Scyphistomae from 'warm' (16°C) parents displayed the greatest reproductive potential (2.63 buds) at medium temperature (12°C). Cold temperature (8°C) caused considerable inhibition of asexual reproduction in offspring scyphistomae, independent of the parental thermal history. Transgenerational acclimation may benefit potentially invasive jellyfish species facing climate-related and/or human-induced changes in the global marine environment, by facilitating asexual reproduction and subsequent bloom events.</p

    Shorter, warmer winters may inhibit production of ephyrae in a population of the moon jellyfish Aurelia aurita

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    Scyphozoan jellyfish blooms display high interannual variability in terms of timing of appearance and size of the bloom. To understand the causes of this variability, the conditions experienced by the polyps prior to the production of ephyrae in the spring were examined. Polyps reared from planula larvae of Aurelia aurita medusae collected from southern England (50°49′58.8; − 1°05′36.9) were incubated under orthogonal combinations of temperature (4, 7, 10 °C) and duration (2, 4, 6, 8 weeks), representing the range of winter conditions in that region, before experiencing an increase to 13 °C. Timing and success of strobilation were recorded. No significant production of ephyrae was observed in any of the 2- and 4-week incubations, or in any 10 °C incubation. Time to first ephyra release decreased with longer winter incubations, and more ephyrae were produced following longer and colder winter simulations. This experiment indicates that A. aurita requires a minimum period of cooler temperatures to strobilate, and contradicts claims that jellyfish populations will be more prevalent in warming oceans, specifically in the context of warmer winter conditions. Such investigations on population-specific ontogeny highlights the need to examine each life stage separately as well as in the context of its environment

    Jellyfish in coastal ecosystems: advances in our understanding of population drivers, role in biogeochemical cycling, and socio-economic impacts

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    Jellyfish (herein, cnidarians and ctenophores) are natural members of marine ecosystems, and are widely distributed in the coastal zone. Flexibility in their physiology, trophic ecology and life history enable several species to form population outbreaks or blooms. Because of the potential impacts blooms have on ecosystem structure and function and human activities, research focuses on understanding their causes and consequences. A brief introduction to jellyfish research from the last 20 years is followed by three areas of recent research: 1) In the complex metagenic life cycle of scyphozoans, which life-stages(s) are the key determinants of population fluctuation? 2) What is the role of jellyfish in nutrient cycling and ecosystem productivity? 3) How are jellyfish detrimental and beneficial to human activity

    Extreme changes in salinity drive population dynamics of Catostylus mosaicus medusae in a modified estuary

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    Modifications to estuaries through the construction of barrages alter the natural dynamics of inhabitant species by controlling freshwater inputs into those systems. To understand the effects of modified freshwater flows on a native scyphozoan jellyfish, Catostylus mosaicus, and to identify the environmental drivers of medusa occurrence, we analysed a 20-year observational dataset composed of 11 environmental variables and medusa presence/absence from 15 sampling stations located below the Fitzroy Barrage, in the Fitzroy River, Queensland. Major decreases in salinity (minimum salinity 0) occurred approximately 16 times during the 20-year period and medusae disappeared from the estuary following every major freshwater flow event. Salinity was identified as the most influential variable contributing to variation in the number of upper estuary sites reporting jellyfish. We then ran two laboratory experiments to test the following hypotheses: (i) prolonged decreases in salinity impair survival, pulsation, and respiration rates of C. mosaicus medusae; and (ii) transient decreases temporarily impair pulsation and respiration but medusae recover when salinity returns to normal levels. Medusae were unable to survive extended periods at extreme low salinities, such that they would experience when a barrage opens fully, but had significantly higher survival and recovery rates following smaller, transient changes to salinity that might occur following a moderate rainfall event. This demonstrates for the first time that modification of freshwater flow by a barrage regulates the population dynamics of an estuarine jellyfish, and highlights the need for robust, long term datasets, and to firmly embed experimental approaches in realistic ecological contexts
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