21 research outputs found

    MEDITS-based information on the deep water red shrimps Aristaeomorpha foliacea and Aristeus antennatus (Crustacea: Decapoda: Aristeidae)

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    Special Volume: Mediterranean marine demersal resources: the Medits international trawl survey (1994-1999)The application of statistical models on a time series of data arising from the MEDITS International Trawl Survey, an experimental demersal resources survey carried out during six years (1994-1999) in the same season of the year (late spring - early summer) using the same fishing gear in a large part of the Mediterranean, has allowed for a study to compare, for the first time, the space-time distribution, abundance, and size structure of the two Aristeids Aristaeomorpha foliacea and Aristeus antennatus throughout most of the Mediterranean Sea. This research has shown a large variability among the six reference areas, that were arbitrarily defined within the basin. In particular the two shrimps do not seem to present any correlation or yield continuity in the years. The same lack of homogeneity was also observed in the time trend of the abundances and frequencies of each of the two species. These data seem to confirm the intrinsic variability of the species, the cause of which is still unknown and undocumented. Nevertheless, a longitudinal gradient of catches has been observed where A. antennatus is more abundant in the west and A. foliacea in the east of the basinVersión del editor1,006

    Scientific, Technical and Economic Committee for Fisheries (STECF) - Stock assessments in the Western Mediterranean Sea (STECF 23-09)

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    801 pagesCommission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines This report documents the outcomes of STECF Expert Working Group 23-09: 2023 stock assessments of demersal stocks in the Western Mediterranean Sea from the meeting held in hybrid mode from 4th to 10th September 2023. A total of 20 fish stocks considered. Nine stocks were evaluated by means of a statistical catch at age (SCAA) model (a4a). Due to the lack of survey information in 2022, five stocks were evaluated through a catch weight projection and short-term forecast. The methodological approach is described in the last part of this Executive Summary, and in the Report. In 2022, index-based advice was given for three stocks (ARA8-9-10-11 and NEP11 on two years basis while for MUT 10 just for one year), and they were re-evaluated by EWG 23-09. The advice for ARA8-9-10-11 and NEP11 have been confirmed while for MUT 10 the missing index information led the group to consider downgrading the advice from an index-based one to a catch only advice approach (ICES Category 5). Two stocks for which the index-based advice provided in 2021 (2 years advice) have been evaluated again looking for a plausible fully analytical assessment. None of the model setting tried was able to provide acceptable results, therefore a biomass index-based advice is given again. The content of the report gives the STECF terms of reference; the basis of the evaluations; assessments, reference point calculations; summaries of state of stock and advised catch or F based on either the MSY approach for assessed stocks and category 3 and 5 based advice for those without assessments. The report contains the full stock assessment reports, the exploration of assessments and category 3 and 5 evaluations for the remaining stocks. The report also contains the STECF observations and conclusions on the assessment report. These conclusions come from the STECF mini plenary meeting October 2023With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

    STECF Fisheries Dependent Information – FDI (STECF-19-11)

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    Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines. The STECF reviewed the report of the EWG on Fisheries-dependent Information during its winter 2019 plenary meeting

    Systematic conservation planning in the Mediterranean: a flexible tool for the identification of no-take marine protected areas

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    We propose the use of systematic conservation planning in the Mediterranean context for the identification of no-take marine protected areas (NTMPAs). We suggest a logical framework that should be used for the identification of areas to be targeted for multispecies, spatially explicit conservation actions. Specifically, we propose seven steps: (i) definition of the study area; (ii) selection of the species or habitats to be considered; (iii) definition of the planning units; (iv) measurement of the fishing effort; (v) definition of the conservation targets; (vi) review of the existing conservation areas; (vii) selection of additional NTMPAs. Moreover, we consider the potential impact of different conservation plans on existing fishing vessels. A working example is presented, focusing on a limited number of species and on a limited study area. This framework can be easily expanded to include datasets of different origin and to accommodate larger spatial scales. Such a process involves major data-collection and capacity-building elements, and conservation of productive commercial fisheries must be a priority

    Scientific, Technical and Economic Committee for Fisheries. Mediterranean Fisheries Assessments Part 2 (STECF-14-19)

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    The STECF expert working group "EWG 1419 - Mediterranean assessment part 2", has convened in Rome during 19-23 January 2015 and addressed a series of issues as requested by DG MARE in the correspomnding terms of references. The detailed output of this working group efforts is included in the following report. The report was reviewed by the STECF spring plenary during 13-17 April 201

    Bathymetric trends in diversity.

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    <p>Variation of the selected indices (ordonnate) according to depth (abscissa) without neutralisation of the effects of year and biogeographical zones (Loess curves with confidence interval). (A) log S, (B) 1/<i>d</i>, (C) Δ<sup>*</sup> (D) Δ<sup>+</sup>, (E) Λ<sup>+</sup>. Codes of diversity indices are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066753#pone-0066753-t001" target="_blank">Table 1</a>.</p

    General results for GAM models of diversity indices.

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    <p>Deviance for Null model. ΔDeviance for the General model (including all the three variables/factors) and for each of the separated factors/variables. df: degree of freedom. ns: non significant effect when <i>p</i> (> ΔDeviance) >0.01. Percentage of the deviance of diversity indices explained by the factors/variables studied are given in brackets.</p

    Spearman rank correlation coefficients calculated between all the diversity indices.

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    <p>All correlations are significantly different from zero (with <i>p</i><0.01), except for underlined values. The Spearman coefficient distribution under null hypothesis was approximated by a normal distribution with mean equal to 0 and standard deviation equal to 1/√ (n–1). Codes of diversity indices are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066753#pone-0066753-t001" target="_blank">Table 1</a>.</p
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