16 research outputs found

    Stock assessment incorporating discards estimates in some years and implications for prediction of future stock trajectories

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    A Bayesian age-structured stock assessment model is developed that takes into account the information available about discards and is able to handle gaps in the time series of discards estimates. The model incorporates a term reflecting mortality due to discarding and appropriate assumptions about how this mortality may change over time are made. The result is a stock assessment that takes due account of the available information on discards while, at the same time, producing a complete time series of discards estimates. The method is applied to the hake stock in ICES divisions VIIIc and IXa, which experiences very high discarding on the younger ages. The stock is fished by Spain and Portugal and for each country there are only discards estimates for recent years. Furthermore, the years for which Portuguese estimates are available are only a subset of the years with Spanish estimates. Two runs of the model are performed, one assuming zero discards and another one incorporating discards. Assessment results and 1 projections of future stock trajectories are compared and discussed and implications for management commented on

    Discards for Southern Hake Stock, a First Approach to Iberian Data

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    This document presents sampling levels obtained with Portuguese and Spanish Discard Sampling Programmes, both included in National Sampling Programmes, and some preliminary results for the Iberian Southern Hake discards. These programs consist on onboard-observer sampling schemes, with co-operative vessels, quasirandom selected, in the ICES Division VIIIc and IXa. The methodology used to estimate hake discards for Portugal and Spain since 2003 was based on the one proposed in the “Workshop on Discard Sampling Methodology and Raising Procedures” (PGCCDBS, Denmark, 2003). Spain presents results for the years 1994, 1997, 1999, 2000, 2003 and 2004. In the Portuguese Program, 2004 is the first year with an analysis of discard data. The number of trips sampled by the Spanish program for 2004 was 53, distributed by three trawl fleets- BACA trawl, Pair trawl and WHVO trawl. Portuguese onboard-observers sampled 40 trips distributed by Crustacean and Fish trawl fleets. The estimated percentages of discarded hake in relation to total catch were of 19,9 (C.V. = 22.6%) and 46,7 (C.V. = 72.1%) for the Spanish and Portuguese fleets respectively. The confidence interval for the Portuguese discard estimate is very large which denotes the very low precision of the obtained value. A co-operation in the analysis of this kind of data, between the two countries, could be the next step, since a standardisation of the methods would be of great importance for a realistic comparison of results obtained from both programs

    STECF Multiannual management plans SWW and NWW (STECF-15-08)

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    The STECF was tasked with an analysis of the likely effects of proposed management plans for the Southwestern (Bay of Biscay and Iberia) and Northwestern (Celtic sea) waters. Quantitative analyses were carried out to compare the likely effect of those management plans and of the direct application of the CFP on both stocks and fleets involved in these fisheries. Based on the results of simulations of the provisions of the proposed management plans, STECF concluded that, setting fishing opportunities in line with single-species FMSY ranges will provide managers with additional flexibility compared to the basic provisions of the 2013 CFP. Such flexibility is likely to help alleviate the problem of mismatches in quota availability in mixed-species fisheries thereby reducing the risk of early closure of some fisheries due to choke species. Adopting FMSY ranges will therefore increase the likelihood that desired exploitation rates will be achieved and will reduce the risk that some fishing fleets will go out of business. STECF considers that it is crucial that managers take note that persistent fishing at the upper limits of the FMSY ranges across all or most stocks simultaneously negates the flexibility introduced by the FMSY ranges and greatly increases the risk of overfishing. Such an approach will also increase the risk that the objectives of the CFP will not be achieved. STECF concludes that single species biomass safeguards for all stocks should be maintained to provide a basic level of protection. STECF notes that for the fleets affected by the SWW MAP, those providing the highest employment are generally not dependent to a great extent on the species that will be regulated through the MAP proposals. STECF notes that in the NWW there are some fleets which provide significant levels of employment and seem to be very dependent on the species that will be regulated through the MAP proposals. Nevertheless, there are a number of fleets in the NWW area that are not included in the employment analysis because of an absence of appropriate data. .Regarding the number and scope of MAPs as currently defined, STECF considers that a MAP covering a wider geographic area has advantages in terms of reducing management overheads and avoiding multiple regulations affecting the sector. A larger MAP area however, may have disadvantages associated with reducing the emphasis on local management measures and this may discourage the involvement of stakeholders, although this effect will depend on how the process of regionalization operates within the MAP. To evaluate the question of whether management of the species that drive the fisheries adequately allows for the management of by-catch species, the EWG carried out an analysis of correlations between catches of driver species identified in the plan and a variety of by-catch species. The analysis suggested only limited correlation. In view of this, the STECF notes that it is unlikely that relying on the TAC of the driver species to manage other species will be effective, in accordance with CFP requirements. STECF however notes that when analysis was performed at the fleet level, there were more obvious correlations, suggesting some scope to use fleet related management measures for the driver species as a way of managing some of the bycatch species. STECF therefore concludes that management of exploitation rates of non-driver (or bycatch) species is unlikely to occur as an automatic consequence of the management of the main (driver) stocks by TAC considered in the MAP.DG MAR

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    A Bayesian stock assessment incorporating discards estimates in some years

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    We develop a Bayesian age-structured stock assessment model that takes into account the information available about discards and is able to handle gaps in the time series of discards estimates. The mechanism for doing this is to explicitly incorporate a term in the model reflecting mortality due to discarding, and to make appropriate assumptions about how this mortality may change over time. The result is a stock assessment that takes due account of discards while, at the same time, producing a complete time series of discards estimates. The method is applied to the hake stock in ICES divisions VIIIc and IXa, which experiences very high discarding on the younger ages. The stock is fished by Spain and Portugal, and for these countries there are only discards estimates in recent and non-coincident years. Two runs of the model are performed, one assuming zero discards and another one incorporating discards. Results are compared and discussed and possible implications for management briefly commented on

    Marine plankton of the Bijagós Archipelago (Guinea-Bissau, West Africa) and its relationship with fish eggs and larvae

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    Results of the joint Guinean-Bissau (CIPA)/Portuguese (UCTRA) marine sciences survey in the Bijagós Archipelago (Guinea-Bissau, West Africa) carried out in May-June 1995 are presented here. Water surface temperature and salinity were measured in 15 stations with T-probe and refactometer

    ICES PGCCDBS Report 2010, ICES Advisory Committee, ICES CM 2010/ACOM:39 - Report of the Planning Group on Commercial Catches, Discards and Biological Sampling (PGCCDBS)

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    The Planning Group on Commercial Catches, Discards and Biological Sampling [PGCCDBS] (Co-Chairs: Christoph Stransky, Germany, and Kjell Nedreaas, Norway) met 1¿5 March 2010 in Lisbon, Portugal. The Planning Group and workshops are proposed in response to the EC-ICES Memorandum of Understanding that requests ICES to provide support for the Data Collection Framework (DCF; EC Reg. 199/2008 and 665/2008, Decisions 2008/949/EC and 2010/93/EU). PGCCDBS is the ICES forum for planning and co-ordination of collection of data for stock assessment purposes; it coordinates and initiates the development of methods and adopts sampling stan-dards and guidelines. Many activities in this group are closely linked to the activities of the DCF, and DG MARE of the European Commission is a member of PGCCDBS to ensure coordination with the DCF activities. Stock assessment requires data cover-ing the total removal from the fish stocks and the PG serves as a forum for coordina-tion with non-EU member countries where appropriate. Since 2007, Mediterranean scientists have organised a Mediterranean Planning Group for Methodological De-velopment (PGMED) to deal with specific sampling issues of this area. Although or-ganised in an autonomous group, it was agreed among all scientists that the contact and cooperation between the Mediterranean area the ICES area should be promoted and maintained. The link between the two planning groups is maintained through: (i) the organisation of parallel meetings; (ii) the organisation of joint plenary sessions for generic issues, and (iii) the organisation of joint workshops.JRC.DG.G.4-Maritime affair
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