Browsing by Author "Azevedo, Manuela"
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- Discards from the Portuguese bottom otter trawl operating in ICES Division 27.9.a (2004-2015)Publication . Fernandes, Ana Cláudia; Prista, Nuno; Azevedo, Manuela; Instituto Português do Mar e da Atmosfera, I.P.This document compiles the information available on discards from Portuguese vessels operating with bottom otter trawl (OTB) in the Portuguese ICES Division 27.9.a, estimated by IPMA for the period 2004- 2015. These discards include species from the stocks assessed in ICES assessment Working Groups and species commercially important at national level. The samples were collected by the onboard sampling programme of the National Programme for Biological Sampling (PNAB/EU DCF), integrated in the National Data Collection Framework . The onboard sampling programme, estimation algorithms and data quality assurance procedures are described and results for two fisheries provided: the crustacean bottom otter trawl fishery (OTB_CRU) and the demersal bottom otter trawl fish fishery (OTB_DEF). Estimates of discard volume and length composition are provided for the ‘year, fishery, species’ combinations where they are frequently observed ( 30% of sampled hauls). Results show that although there’s a large number of species discarded, the number of species frequently discarded is very low (7% in OTB_CRU and 4% in OTB_DEF). Mean number of discards per haul is calculated for all species that occurred in discards and analysis of length compositions are displayed for selected species. Analyses of the combined results indicates that a large part of the species selected for this work are either absent in discards or very rarely discarded. Indications are given on possible discarding reasons and on the discard estimation methodology to be developed for less frequent species and for other Portuguese fleet components.
- O LABORATÓRIO DE ESCLEROCRONOLOGIA E OS ESTUDOS DE IDADE E CRESCIMENTO DE RECURSOS DA PESCAPublication . Farias, Inês; Soares, Eduardo; Moreno, Ana; Ferreira, Ana Luísa; Silva, Andreia; Serra-Pereira, Bárbara; Dinis, David; Morais, Delfina; Silva, Dina; Santos, Eduardo; Meneses, Isabel; Ferreira, Maria João; Lagarto, Neide; Gonçalves, Patrícia; Alpoim, Ricardo; Dores, Sandra; Garrido, Susana; Moura, Teresa; Azevedo, Manuela; Figueiredo, Ivone; Instituto Português do Mar e da AtmosferaThe Laboratory of Sclerochronology and the age and growth studies of fishing resources A brief description of the growth studies developed by IPMA, I.P. is given in this report, with emphasis on the halieutic species currently studied both within the scope of the National Programme of Biological Sampling (under the EU/DG Fisheries’ Data Collection Framework (DCF)) as of other research projects and research lines of interest for the Institute. With the aim of disseminating the importance of the multiple growth studies and of their application to improve the knowledge on the biology and dynamics of the commercially exploited species, a summary of the techniques and methodologies applied in the Laboratory of eclerochronology is included.
- Long-Term Management Strategy for Southern Horse Mackerel (hom27.9a) Management Strategy EvaluationPublication . Azevedo, Manuela; Mendes, Hugo; Costas, Gersom; Jardim, Ernesto; Mosqueira, Iago; Scott, FinlayThe development of the long term management strategy (LTMS) for southern horse mackerel (Trachurus trachurus) started in October 2014 through a dialogue process between scientists and stakeholders. The process involved the definition of management objectives, a Harvest Control Rule and several TAC setting options, the FMSY target year, and catch stability levels proposed by the stakeholders of Pelagic Advisory Council (PelAC) and the South West Waters Advisory Council (SWWAC). The PelAC in October 2017 sent a proposal for a LTMS for southern horse mackerel to the European Commission with a request that this be scientifically assessed. The Commission requested ICES to evaluate whether the proposed plan is seen as precautionary and to assess if the plan ensures that the stock is fished and maintained, also in the future, at levels which can produce Maximum Sustainable Yield (MSY). This report presents the Management Strategy Evaluation (MSE) on the performance of the LTMS. The conditioning of the operating model is based on the latest stock assessment, following the stock benchmark in early 2017, and with recruitment stochasticity. To implement a full-feedback MSE the management procedure component includes a stock assessment and advice cycle. The stock assessment cycle, with observation error, is performed using a statistical catch-at-age model that mimics the current assessment method. Two hundred populations are simulated from 2017 to 2080. Performance statistics for catch, spawning stock biomass and fishing mortality are computed for the short (2017-2027) and long-term (2070-2080). The proposed LTMS, with a Harvest Control Rule defined by FMSY at 0.11, Fby-catch at 0.01, MSY Btrigger at 181 kt and Blim at 103 kt and with a ±15% catch constraint is precautionary as the probability of SSB being below Blim is less than 5% over the entire simulated period. The long-term equilibrium catches of the LTMS are very close to MSY. Sensitivity analyses indicate that the LTMS is also precautionary in a low productivity scenario.
- Report of the Workshop on Sampling Design and Optimization of fisheries data - WKSDOPublication . Azevedo, Manuela; Silva, Cristina; Vølstad, Jon Helge; Prista, Nuno; Alpoim, Ricardo; Moura, Teresa; Figueiredo, Ivone; Dias, Marina; Fernandes, Ana Cláudia; Lino, Pedro G.; Felício, Mónica; Chaves, Corina; Soares, Eduardo; Dores, Sandra; Gonçalves, Patrícia; Costa, Ana Maria; Nunes, Cristina; Instituto Português do Mar e da Atmosfera, I.P.O “Workshop on Sampling Design and Optimization (WKSDO)”, presidido pelas investigadoras Cristina Silva e Manuela Azevedo (IPMA) e o investigador Norueguês Jon H. Vølstad (IMR), decorreu no IPMAAlgés, de 17 a 20 de Novembro de 2014, para analisar o actual Programa Nacional de Amostragem Biológica (PNAB/Data Collection Framework) com o objectivo de optimizar o programa de amostragem em lota para estimação da composição por comprimento da captura/desembarque das espécies capturadas pela frota nacional, de amostragem das capturas a bordo e da amostragem biológica para estudos de crescimento e reprodução. O Workshop, organizado no âmbito do projecto de investigação nacional GesPe (Planos de Gestão Pesqueira, PROMAR) e do PNAB/DCF, foi planeado e calendarizado tendo em conta o início do processo de revisão do programa Europeu de recolha de dados da pesca de suporte à avaliação e gestão dos recursos pesqueiros (DFC). Foram analisados e discutidos vários métodos e abordagens que resultaram num conjunto de instruções e recomendações para trabalho futuro, relevantes para assegurar uma elevada qualidade e optimização do futuro programa de amostragem.