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Improve Scientific and Technical Advices for Fisheries Management | ![]() Français |
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| ![]() This WP is devoted to the analysis and to improvement of existing national systems of fisheries monitoring in terms of landing and fishing effort surveys (WP1a) and in terms of scientific fish sampling (mainly demersal resources) (WP1b). This WP will be developed at national level. The two work themes involved in WP1a and WP1b will rely on: (i) a review of the existing systems with an explicit and standardised description of the sampling plans (definition of the various strata, the populations of these strata and the rules for choosing samples per stratum) and (ii) an analysis of the quality (precision) data collected and the estimations that they can be used to produce (e.g. nominal efforts per strata, catches for various combinations of fishing gear and/or species and/or time period and/or geographical sector). WP1.1 Monitoring commercial fisheries (National level) The objectives are:
WP1.2 Monitoring resources by scientific trawling surveys (National level) This proposes completing the work conducted during FIAS project along three main directions:
WP1.1 Documentation of the available data sets Although most statistical systems for fisheries monitoring have been in place for many years, it is generally difficult to find documentation that can provide an understanding of how the statistics were produced, both in terms of the workings of the survey systems (sampling procedures, nomenclature used) and in terms of the data processing and extrapolation procedures. It is therefore necessary to conduct a retrospective reconstitution of the documentation on the data and their production, for the case studies selected. This will allow us to conduct a "cleaning"/ validation of the databases and to attach validity criteria to them. Similarly, the creation of nomenclature systems compatible over time will enable us to reconstitute useable chronological series. Analysis - diagnosis of monitoring systems, for AF and IF This will involve firstly (1) comparing the monitoring systems with their objectives, i.e. with respect to the nature of the information to be produced, (2) considering the designs and procedures for collecting data and making calculations in terms of their effectiveness in producing the desired information and finally (3) assessing the quality of the information produced. When the defects in the existing system are too great on one or more aspects, a need for restructuring or rethinking could be formulated. Defining the qualities of the estimators associated with survey systems could be done using traditional theoretical methods of sampling or in a more intuitive and visual method of resampling that is now easy to do on computers. Writing standard specifications and drawing up a quality charter The analysis of the selected monitoring systems will enable us to produce recommendations (standard specifications) and draw up quality charters for these systems. A monitoring system usually consists of several modules providing the following major functions:
There are conception difficulties on each of these aspects that the charter will deal with.
Work WP1.2 Extension/updating of the existing database We envisage extending the TrawlBase database (1) geographically: (to other COPACE countries), (2) in time (updating the data, additional historical data), (3) if needed to supplementary data, useful for interpretation and/or analysis (environmental data) Validation and documentation (meta-information) of the data The histories of information systems, known to regional experts involved in past and/or present samplings, will be mobilised so as to enrich and improve the meta-information associated with the survey data series. Careful examination of the data, which goes hand-in-hand with their documentation, should be able to correct possible errors that could exist in old data that has been subject to several transfers from successive database formats (validation). Work on the taxonomic nomenclature in the surveys conducted in the region Definition and conversion into a reference taxonomic nomenclature of scientific surveys conducted in the region. This implies both an expertise aspect (biological knowledge, knowledge of how the sampling was conducted, examination of data etc.) and technical software knowledge (development of automatic conversion procedures). Quality of the estimates Statistically, the quality of the estimates is often quantified by the variances of the estimates. The calculation of such values can be laborious from both a theoretical and also practical viewpoint since it requires specialist computer software. However, when it is used, this information is especially important by its orders of magnitude. In fact, what is important for the final user is whether the estimate of abundance provided by the survey is precise to within 10, 50 or 100 %. In this context, pragmatic approaches will be set up on certain case studies in order to develop simple and easily obtained tools to provide an order of magnitude for the variances of the estimates. Delivrables Deliverables
Persons involved in the working package Ebaye Ould Sidina Case studies Collection and management of some specific informationFisheries observer programs. Description and complementarity with other monitoring systems Good practices and general methodology Inventory and description of monitoring systems |
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03/07/2022 |