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  • 1
    In: Fisheries Oceanography, Wiley, Vol. 22, No. 2 ( 2013-03), p. 121-139
    Type of Medium: Online Resource
    ISSN: 1054-6006
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2013
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    SSG: 21,3
    SSG: 12
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  • 2
    Online Resource
    Online Resource
    Wiley ; 2016
    In:  Fish and Fisheries Vol. 17, No. 3 ( 2016-09), p. 596-616
    In: Fish and Fisheries, Wiley, Vol. 17, No. 3 ( 2016-09), p. 596-616
    Abstract: Reference points based on fishing mortality ( F ) and spawning stock biomass ( SSB ) are a requirement of many fisheries management frameworks. SSB is assumed to be a proxy for stock reproductive potential ( SRP ). Limit reference points based on SSB are used to indicate the level of biomass below which productivity is affected. SSB fails to account for changes in fecundity, egg viability and sex ratio, and it has been argued that total egg production ( TEP ) provides a better reflection of SRP . We explore how accounting for TEP impacts limit reference points and evidence for a relationship between stock and recruit. Time series of SSB and TEP are compared for three North Sea stocks: cod ( Gadus morhua ), herring ( Clupea harengus ) and plaice ( Pleuronectes platessa ). Dynamics based on TEP are different from those based on SSB for cod and plaice, but the stock–recruit relationships were not ‘improved’ using TEP . Shifts in productivity (spawner per recruit) occur in all three time series and SSB underestimated uncertainty. Yet again, it was shown that assumptions of stationarity about fish population productivity are incorrect. We argue that the use of TEP does improve the realism in our understanding of stock dynamics, and demographically, more complex management strategy evaluation is required to develop management procedures that are robust to uncertainty and integrate F and the demographic health of a stock. Empirical feedback control systems based on fisheries independent indices including surveys of eggs, larvae, recruits, juveniles or spawning adults should be evaluated and compared to traditional approaches.
    Type of Medium: Online Resource
    ISSN: 1467-2960 , 1467-2979
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2016
    detail.hit.zdb_id: 2024569-5
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  • 3
    In: Journal of Fish Biology, Wiley, Vol. 99, No. 2 ( 2021-08), p. 569-580
    Abstract: Lemon sole Microstomus kitt is a commercially valuable flatfish species that occurs in shelf waters around the northeast Atlantic. Only the most basic life‐history information is available for the North Sea. Spawning is generally assumed to occur between early May and October, with a peak between May and August. Lemon sole larvae have been found in the water column in the northern North Sea in winter during standard surveys. Larvae captured in November/December 2016 and January/February 2017 using the International Council for the Exploration of the Seas standard 2 m Midwater Ring trawls (MIK) were analysed to gain a better understanding of the pelagic early life‐history stages of lemon sole, especially in relation to the timing of spawning and the dispersal of overwintering larvae. Larval age was estimated from sagittal otolith primary increment counts. The larvae caught in November/December ranged in nominal age from 4 to 45 days post‐hatching which suggests that spawning continues into late October and November. Most, but not all, of the larvae caught in January/February were post metamorphosis, and the difference in age between the two sampling dates was consistent with the elapsed time between samplings. The estimated hatching dates confirm that lemon sole spawning extends into late autumn in the northern North Sea, with overwintering larvae in all developmental stages. Drift modelling of eggs and larvae released at historically documented spawning grounds in the northern North Sea suggests that these grounds are also the source for all of the larvae sampled during the 2016–2017 surveys.
    Type of Medium: Online Resource
    ISSN: 0022-1112 , 1095-8649
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2021
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    SSG: 12
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  • 4
    Online Resource
    Online Resource
    Wiley ; 2021
    In:  Journal of Fish Biology Vol. 98, No. 4 ( 2021-04), p. 1112-1119
    In: Journal of Fish Biology, Wiley, Vol. 98, No. 4 ( 2021-04), p. 1112-1119
    Abstract: The estimation of growth rates in young herring larvae ( Clupea harengus ) in the field can be difficult because the primary increments in the otoliths may not be discernible or formed at a daily level. Likewise, the estimation of mortality rates of fish larvae in the field is very difficult to achieve, especially in a rigorous quantitative manner. In this study, the authors suggest the use of a stage‐based proxy of feeding success, growth and potential survival or mortality risk of field‐caught larvae. The stage‐based proxy is derived based on observations from previous laboratory studies where larvae successfully completing start‐feeding on external food sources will advance through the early development stages, whereas those that do not (unsuccessful larvae) remain and accumulate in the development stage preceding first feeding. The relative occurrence of larvae in the early development stages is therefore expected to reflect feeding conditions of the larvae, with higher ratios of unsuccessful larvae indicative of poor feeding success and higher mortality risk. Using field data on Norwegian spring spawning herring, the authors document that the relative occurrence of larvae in the late non‐feeding stage is significantly higher at lower average zooplankton concentrations, in line with the predictions of the authors that this novel approach of using a stage‐based proxy could be a useful indication of feeding success, growth and mortality in the field. Further, there was a significant interaction effect with ambient temperature, with the ratio being higher at low zooplankton concentrations at higher temperatures. This study also suggests that these findings are not population specific as the same accumulation of non‐feeding larvae in the late non‐feeding stage was observed in laboratory‐reared larvae of both autumn and spring spawning herring populations.
    Type of Medium: Online Resource
    ISSN: 0022-1112 , 1095-8649
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2021
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    detail.hit.zdb_id: 1471958-7
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    SSG: 12
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  • 5
    In: Ecology and Evolution, Wiley, Vol. 11, No. 4 ( 2021-02), p. 1691-1718
    Abstract: Habitat changes represent one of the five most pervasive threats to biodiversity. However, anthropogenic activities also have the capacity to create novel niche spaces to which species respond differently. In 1880, one such habitat alterations occurred in Landvikvannet, a freshwater lake on the Norwegian coast of Skagerrak, which became brackish after being artificially connected to the sea. This lake is now home to the European sprat, a pelagic marine fish that managed to develop a self‐recruiting population in barely few decades. Landvikvannet sprat proved to be genetically isolated from the three main populations described for this species; that is, Norwegian fjords, Baltic Sea, and the combination of North Sea, Kattegat, and Skagerrak. This distinctness was depicted by an accuracy self‐assignment of 89% and a highly significant F ST between the lake sprat and each of the remaining samples (average of ≈0.105). The correlation between genetic and environmental variation indicated that salinity could be an important environmental driver of selection (3.3% of the 91 SNPs showed strong associations). Likewise, Isolation by Environment was detected for salinity, although not for temperature, in samples not adhering to an Isolation by Distance pattern. Neighbor‐joining tree analysis suggested that the source of the lake sprat is in the Norwegian fjords, rather than in the Baltic Sea despite a similar salinity profile. Strongly drifted allele frequencies and lower genetic diversity in Landvikvannet compared with the Norwegian fjords concur with a founder effect potentially associated with local adaptation to low salinity. Genetic differentiation ( F ST ) between marine and brackish sprat is larger in the comparison Norway‐Landvikvannet than in Norway‐Baltic, which suggests that the observed divergence was achieved in Landvikvannet in some 65 generations, that is, 132 years, rather than gradually over thousands of years (the age of the Baltic Sea), thus highlighting the pace at which human‐driven evolution can happen.
    Type of Medium: Online Resource
    ISSN: 2045-7758 , 2045-7758
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 2635675-2
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  • 6
    In: Evolutionary Applications, Wiley, Vol. 13, No. 8 ( 2020-09), p. 1906-1922
    Abstract: Sustainable fisheries management requires detailed knowledge of population genetic structure. The European sprat is an important commercial fish distributed from Morocco to the Arctic circle, Baltic, Mediterranean, and Black seas. Prior to 2018, annual catch advice on sprat from the International Council for the Exploration of the Sea (ICES) was based on five putative stocks: (a) North Sea, (b) Kattegat–Skagerrak and Norwegian fjords, (c) Baltic Sea, (d) West of Scotland—southern Celtic Seas, and (e) English Channel. However, there were concerns that the sprat advice on stock size estimates management plan inadequately reflected the underlying biological units. Here, we used ddRAD sequencing to develop 91 SNPs that were thereafter used to genotype approximately 2,500 fish from 40 locations. Three highly distinct and relatively homogenous genetic groups were identified: (a) Norwegian fjords; (b) Northeast Atlantic including the North Sea, Kattegat–Skagerrak, Celtic Sea, and Bay of Biscay; and (c) Baltic Sea. Evidence of genetic admixture and possibly physical mixing was detected in samples collected from the transition zone between the North and Baltic seas, but not between any of the other groups. These results have already been implemented by ICES with the decision to merge the North Sea and the Kattegat–Skagerrak sprat to be assessed as a single unit, thus demonstrating that genetic data can be rapidly absorbed to align harvest regimes and biological units.
    Type of Medium: Online Resource
    ISSN: 1752-4571 , 1752-4571
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2020
    detail.hit.zdb_id: 2405496-3
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  • 7
    In: Fish and Fisheries, Wiley
    Abstract: Climate change continues to exert pressure on ocean ecosystems. The fisheries‐related responses, such as altered body growth, recruitment and spatial distribution of the targeted stock(s), have generally been reasonably well investigated. Nevertheless, there are still important knowledge gaps in how biophysical drivers impact stock productivity and thereby sustainable harvest levels. Considering this, we investigated 26 fish stocks in the Northeast Atlantic, a region characterized by accelerated climate change effects and a diverse set of fisheries. A novel, stepwise, Bayesian framework to quantify stock productivity was established to identify shared trends and project future patterns, aiming at determining essential baselines for adaptive fishery management in the face of climate change. Despite variation among large marine ecosystems and stocks, an overall declining trend in productivity over the past four decades was observed, especially in high‐latitude areas. These hindcast results were mainly attributed to higher temperatures posing negative effects on productivity, which was dependent on the stock's thermal preference. Contrastingly, the proxy for food availability – gross secondary production – exhibited less consistent impacts. In the forecast, the applied Shared Socio‐economic Pathways (SSPs) indicated that most stocks are likely to encounter adverse effects, with the worst cases expected to occur under SSP2‐4.5 in the 2050s, and under SSP5‐8.5 in the 2090s. Thus, this study generally not only supports earlier climate vulnerability assessments (‘scorings’) of experts but also provides evidence for revised directional effects under climate change, underlining the complexity of processes affecting stock productivity.
    Type of Medium: Online Resource
    ISSN: 1467-2960 , 1467-2979
    Language: English
    Publisher: Wiley
    Publication Date: 2024
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    SSG: 12
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  • 8
    In: JBMR Plus, Wiley, Vol. 2, No. S1 ( 2018-09)
    Type of Medium: Online Resource
    ISSN: 2473-4039 , 2473-4039
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2018
    detail.hit.zdb_id: 2905710-3
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  • 9
    In: Astronomische Nachrichten, Wiley, Vol. 344, No. 8-9 ( 2023-10)
    Abstract: Since the start of science operations in 1993, the twin 10‐m W. M. Keck Observatory (WMKO) telescopes have continued to maximize their scientific impact and to produce transformative discoveries that keep the observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided through collaborative partnerships with Caltech, the University of California, and the University of Hawaii instrument development teams along with industry and other organizations. The observatory adapts and responds to the observers' evolving needs as defined in the observatory's strategic plan periodically refreshed in collaboration with the science community. This paper is an overview of the instrumentation projects that range from commissioning to early conceptual stages. An emphasis is placed on the detector, detector controllers, and capability needs that are driven by the desired future technology defined in the 2022 strategic plan.
    Type of Medium: Online Resource
    ISSN: 0004-6337 , 1521-3994
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2025762-4
    detail.hit.zdb_id: 2171222-0
    SSG: 16,12
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  • 10
    In: Journal of the International AIDS Society, Wiley, Vol. 17, No. 1 ( 2014-01)
    Abstract: HIV care and treatment programmes worldwide are transforming as they push to deliver universal access to essential prevention, care and treatment services to persons living with HIV and their communities. The characteristics and capacity of these HIV programmes affect patient outcomes and quality of care. Despite the importance of ensuring optimal outcomes, few studies have addressed the capacity of HIV programmes to deliver comprehensive care. We sought to describe such capacity in HIV programmes in seven regions worldwide. Methods Staff from 128 sites in 41 countries participating in the International epidemiologic Databases to Evaluate AIDS completed a site survey from 2009 to 2010, including sites in the Asia‐Pacific region ( n= 20), Latin America and the Caribbean ( n= 7), North America ( n= 7), Central Africa ( n= 12), East Africa ( n= 51), Southern Africa ( n= 16) and West Africa ( n= 15). We computed a measure of the comprehensiveness of care based on seven World Health Organization‐recommended essential HIV services. Results Most sites reported serving urban (61%; region range (rr): 33–100%) and both adult and paediatric populations (77%; rr: 29–96%). Only 45% of HIV clinics that reported treating children had paediatricians on staff. As for the seven essential services, survey respondents reported that CD4+ cell count testing was available to all but one site, while tuberculosis (TB) screening and community outreach services were available in 80 and 72%, respectively. The remaining four essential services – nutritional support (82%), combination antiretroviral therapy adherence support (88%), prevention of mother‐to‐child transmission (PMTCT) (94%) and other prevention and clinical management services (97%) – were uniformly available. Approximately half (46%) of sites reported offering all seven services. Newer sites and sites in settings with low rankings on the UN Human Development Index (HDI), especially those in the President's Emergency Plan for AIDS Relief focus countries, tended to offer a more comprehensive array of essential services. HIV care programme characteristics and comprehensiveness varied according to the number of years the site had been in operation and the HDI of the site setting, with more recently established clinics in low‐HDI settings reporting a more comprehensive array of available services. Survey respondents frequently identified contact tracing of patients, patient outreach, nutritional counselling, onsite viral load testing, universal TB screening and the provision of isoniazid preventive therapy as unavailable services. Conclusions This study serves as a baseline for on‐going monitoring of the evolution of care delivery over time and lays the groundwork for evaluating HIV treatment outcomes in relation to site capacity for comprehensive care.
    Type of Medium: Online Resource
    ISSN: 1758-2652 , 1758-2652
    Language: English
    Publisher: Wiley
    Publication Date: 2014
    detail.hit.zdb_id: 2467110-1
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