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  • 1
    In: Journal of Operational Oceanography, Informa UK Limited, Vol. 13, No. sup1 ( 2020-08-21), p. S1-S172
    Type of Medium: Online Resource
    ISSN: 1755-876X , 1755-8778
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2428097-5
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  • 2
    Online Resource
    Online Resource
    Canadian Science Publishing ; 2015
    In:  Canadian Journal of Fisheries and Aquatic Sciences Vol. 72, No. 6 ( 2015-06), p. 864-878
    In: Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 72, No. 6 ( 2015-06), p. 864-878
    Abstract: An application of the Spatial Ecosystem And POpulation DYnamics Model (SEAPODYM) is developed for the North Atlantic albacore (Thunnus alalunga) population. We investigate the spatiotemporal dynamics of this species, distinguishing the influences of environment and international fishing. Incorporating historical data (1960–2008), a maximum likelihood approach allows the estimation of biological parameters (thermal and oxygen tolerance) and stock spatial distribution varying over time. Juvenile albacore are predicted in warm surface waters, whereas adults inhabit cooler and deeper waters. Positive correlations between juveniles and tropical large-scale climate indices highlight the importance of environmental drivers when estimating stock recruitment biology and spatiotemporal distribution. A methodology is proposed to use SEAPODYM outputs to estimate stock abundance and maximum sustainable yield (MSY). MSY is computed taking into account the spatial dynamics of the species and the environmental variability and is based on a mechanistic modelling of larval recruitment. MSY estimates converge towards an asymptotic value (15 997 t) of the same magnitude than standard stock assessment estimates conducted for the international tuna commission. In agreement with all assessment studies, the stock status is estimated from overfished in the 1990s to recovered in the 2000s. Our results show that the stock recovery results both from fishing actions, including total allowable catches established in the 2000s, and from the beginning of a North Atlantic Oscillation warm phase, leading to more favourable recruitment conditions. Following a parsimonious ecosystemic approach, SEAPODYM offers a faithful and spatially dynamic modelling framework that now includes direct tools for spatialized management advice and for distinction between environmental and fishing effects.
    Type of Medium: Online Resource
    ISSN: 0706-652X , 1205-7533
    Language: English
    Publisher: Canadian Science Publishing
    Publication Date: 2015
    detail.hit.zdb_id: 7966-2
    detail.hit.zdb_id: 1473089-3
    SSG: 21,3
    SSG: 12
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  • 3
    In: Frontiers in Sustainable Food Systems, Frontiers Media SA, Vol. 7 ( 2023-5-19)
    Abstract: National and global priorities are increasingly focused on the concurrent marine fisheries challenges of food security, illegal fishing, and declining fisheries resources. Molecular genetics and electronic monitoring technologies can advance solutions to these challenges, particularly in fisheries surveillance and seafood traceability, and a growing number of studies continues to validate the utility of these tools. What is needed next is guidance to support their wider, more conventional adoption and implementation, either complementary to or in the absence of government policies. Here, we synthesize discussion held during the Borchard Foundation Colloquium held in July 2022 in Missillac, France on modernizing global fisheries with emerging technologies. Our aim is to provide perspectives to scientists, resource managers, and policy makers of emerging monitoring technologies, summarize the utility of these technologies in fisheries, and conclude with how the objective to modernize global marine fisheries is a prime opportunity to engage fresh talent in a new era of fisheries innovation.
    Type of Medium: Online Resource
    ISSN: 2571-581X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2928540-9
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  • 4
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2015
    In:  ICES Journal of Marine Science Vol. 72, No. 5 ( 2015-06-01), p. 1399-1412
    In: ICES Journal of Marine Science, Oxford University Press (OUP), Vol. 72, No. 5 ( 2015-06-01), p. 1399-1412
    Abstract: In the pelagic foodweb, micronekton at the mid-trophic level (MTL) are one of the lesser known components of the ocean ecosystem despite being a major driver of the spatial dynamics of their predators, of which many are exploited species (e.g. tunas). The Spatial Ecosystem and Population Dynamics Model is one modelling approach that includes a representation of the spatial dynamics of several epi- and mesopelagic MTL functional groups. The dynamics of these groups are driven by physical (temperature and currents) and biogeochemical (primary production, euphotic depth) variables. A key issue to address is the parameterization of the energy transfer from the primary production to these functional groups. We present a method using in situ acoustic data to estimate the parameters with a maximum likelihood estimation approach. A series of twin experiments conducted to test the behaviour of the model suggested that in the ideal case, that is, with an environmental forcing perfectly simulated and biomass estimates directly correlated with the acoustic signal, a minimum of 200 observations over several time steps at the resolution of the model is needed to estimate the parameter values with a minimum error. A transect of acoustic backscatter at 38 kHz collected during scientific cruises north of Hawaii allowed a first illustration of the approach with actual data. A discussion followed regarding the various sources of uncertainties associated with the use of acoustic data in micronekton biomass.
    Type of Medium: Online Resource
    ISSN: 1095-9289 , 1054-3139
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2015
    detail.hit.zdb_id: 2463178-4
    detail.hit.zdb_id: 1468003-8
    detail.hit.zdb_id: 29056-7
    SSG: 12
    SSG: 21,3
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  • 5
    Online Resource
    Online Resource
    Copernicus GmbH ; 2020
    In:  Biogeosciences Vol. 17, No. 4 ( 2020-02-18), p. 833-850
    In: Biogeosciences, Copernicus GmbH, Vol. 17, No. 4 ( 2020-02-18), p. 833-850
    Abstract: Abstract. Micronekton – small marine pelagic organisms around 1–10 cm in size – are a key component of the ocean ecosystem, as they constitute the main source of forage for all larger predators. Moreover, the mesopelagic component of micronekton that undergoes diel vertical migration (DVM) likely plays a key role in the transfer and storage of CO2 in the deep ocean: this is known as the “biological pump”. SEAPODYM-MTL is a spatially explicit dynamical model of micronekton. It simulates six functional groups of vertically migrant (DVM) and nonmigrant (no DVM) micronekton, in the epipelagic and mesopelagic layers. Coefficients of energy transfer efficiency between primary production and each group are unknown, but they are essential as they control the production of micronekton biomass. Since these coefficients are not directly measurable, a data assimilation method is used to estimate them. In this study, Observing System Simulation Experiments (OSSEs) are used at a global scale to explore the response of oceanic regions regarding energy transfer coefficient estimation. In our experiments, we obtained different results for spatially distinct sampling regions based on their prevailing ocean conditions. According to our study, ideal sampling areas are warm and productive waters associated with weak surface currents like the eastern side of tropical oceans. These regions are found to reduce the error of estimated coefficients by 20 % compared to cold and more dynamic sampling regions.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2020
    detail.hit.zdb_id: 2158181-2
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  • 6
    Online Resource
    Online Resource
    Frontiers Media SA ; 2023
    In:  Frontiers in Marine Science Vol. 10 ( 2023-7-25)
    In: Frontiers in Marine Science, Frontiers Media SA, Vol. 10 ( 2023-7-25)
    Abstract: Robust prediction of population responses to changing environments requires the integration of factors controlling population dynamics with processes affecting distribution. This is true everywhere but especially in polar pelagic environments. Biological cycles for many polar species are synchronised to extreme seasonality, while their distributions may be influenced by both the prevailing oceanic circulation and sea-ice distribution. Antarctic krill (krill, Euphausia superba ) is one such species exhibiting a complex life history that is finely tuned to the extreme seasonality of the Southern Ocean. Dependencies on the timing of optimal seasonal conditions have led to concerns over the effects of future climate on krill’s population status, particularly given the species’ important role within Southern Ocean ecosystems. Under a changing climate, established correlations between environment and species may breakdown. Developing the capacity for predicting krill responses to climate change therefore requires methods that can explicitly consider the interplay between life history, biological conditions, and transport. The Spatial Ecosystem And Population Dynamics Model (SEAPODYM) is one such framework that integrates population and general circulation modelling to simulate the spatial dynamics of key organisms. Here, we describe a modification to SEAPODYM, creating a novel model – KRILLPODYM – that generates spatially resolved estimates of krill biomass and demographics. This new model consists of three major components: (1) an age-structured population consisting of five key life stages, each with multiple age classes, which undergo age-dependent growth and mortality, (2) six key habitats that mediate the production of larvae and life stage survival, and (3) spatial dynamics driven by both the underlying circulation of ocean currents and advection of sea-ice. We present the first results of KRILLPODYM, using published deterministic functions of population processes and habitat suitability rules. Initialising from a non-informative uniform density across the Southern Ocean our model independently develops a circumpolar population distribution of krill that approximates observations. The model framework lends itself to applied experiments aimed at resolving key population parameters, life-stage specific habitat requirements, and dominant transport regimes, ultimately informing sustainable fishery management.
    Type of Medium: Online Resource
    ISSN: 2296-7745
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2757748-X
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  • 7
    In: Ecological Indicators, Elsevier BV, Vol. 147 ( 2023-03), p. 109943-
    Type of Medium: Online Resource
    ISSN: 1470-160X
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
    detail.hit.zdb_id: 2063587-4
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  • 8
    In: Progress in Oceanography, Elsevier BV, Vol. 142 ( 2016-03), p. 58-71
    Type of Medium: Online Resource
    ISSN: 0079-6611
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2016
    detail.hit.zdb_id: 1497436-8
    detail.hit.zdb_id: 4062-9
    SSG: 21,3
    SSG: 14
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