Coelho Phd Lantern S
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UNIVERSIDADEdo ALGARVE FaculdadedeCiênciasdoMaredo Ambiente Biology,populationdynamics,managementandconservation ofdeepwaterlanternsharks,Etmopterusspinax and Etmopteruspusillus (Chondrichthyes:Etmopteridae)insouthernPortugal(northeastAtlantic). (DoutoramentoemCiênciaseTecnologiasdasPescas,especialidadedeBiologiaPesqueira) (ThesisforthedegreeinDoctorofPhilosophyinFisheriesSciencesandTechnologies,specialtyinFisheriesBiology) RUIPEDROANDRADECOELHO Faro (2007) UNIVERSIDADE DO ALGARVE FACULDADE DE CIÊNCIAS DO MAR E DO AMBIENTE Biology, population dynamics, management and conservation of deep water lantern sharks, Etmopterus spinax and Etmopterus pusillus (Chondrichthyes: Etmopteridae) in southern Portugal (northeast Atlantic). (Doutoramento em Ciências e Tecnologias das Pescas, especialidade de Biologia Pesqueira) (Thesis for the degree in Doctor of Philosophy in Fisheries Sciences and Technologies, specialty in Fisheries Biology) RUI PEDRO ANDRADE COELHO Orientador / Supervisor: Prof. Doutor Karim Erzini Júri / Jury: - Prof. Doutor José Pedro Andrade, Professor Catedrático da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve; - Prof. Doutor Karim Erzini, Professor Associado com Agregação da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve; - Prof. Doutor Leonel Paulo Sul de Serrano Gordo, Professor Auxiliar com Agregação da Faculdade de Ciências, Universidade de Lisboa; - Prof. Doutor Manuel Seixas Afonso Dias, Professor Auxiliar da Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve; - Doutora Ivone Maria Ribeiro Figueiredo da Silva Rosa, Investigadora Auxiliar do INIAP-IPIMAR, Instituto Nacional de Investigação Agrária e das Pescas; - Doutor Jorge Manuel dos Santos Gonçalves, Investigador Auxiliar do Centro de Ciências do Mar, Universidade do Algarve. FARO (2007) Cover: Etmopterus head drawing by Patricia Tello. Cover design by Frederico Oliveira. Abstract NAME: Rui Pedro Andrade Coelho FACULTY: Faculdade de Ciências do Mar e do Ambiente / Universidade do Algarve SUPERVISOR: Prof. Dr. Karim Erzini DATE: November 2007 THESIS TITLE: Biology, population dynamics, management and conservation of deep water lantern sharks, Etmopterus spinax and Etmopterus pusillus (Chondrichthyes: Etmopteridae) in southern Portugal (northeast Atlantic). Abstract Deep water sharks are particularly vulnerable to fishing mortality with population collapses occurring even at low levels of fishing. Two lantern sharks species, Etmopterus spinax and E. pusillus, are commonly caught as by-catch in commercial fisheries that operate in southern Portuguese waters. Little is known about the fisheries biology of these two species that have low or null commercial value and are usually discarded. The present study focused on several aspects of these two species, including fisheries, morphology, life history, distribution patterns and population dynamics. Commercial fisheries are having an impact on these species, with different gears affecting different components of the populations, as well as critical areas such as mating and nursery areas. Multivariate analysis was used to efficiently separate these two very similar and easily mistakable species, and models were created for future studies to more easily discriminate these species. Life history parameters, specifically age, growth, fecundity, maturity and reproductive seasonality, were determined and incorporated in mortality and demographic models. The results indicate that the current fishing pressures in the south of Portugal are not sustainable and the populations are declining. Urgent conservation measurements are therefore needed. Key-words: deep-water; fisheries; life-history; management; population dynamics; sharks. - 1 - - 2 - Resumo NOME: Rui Pedro Andrade Coelho FACULDADE: Faculdade de Ciências do Mar e do Ambiente / Universidade do Algarve ORIENTADOR: Prof. Dr. Karim Erzini DATA: November de 2007 TÍTULO DA TESE: Biologia, dinâmica populacional, gestão e conservação de tubarões lanterna de profundidade, Etmopterus spinax e Etmopterus pusillus (Chondrichthyes: Etmopteridae), na costa sul de Portugal (Atlântico nordeste). Resumo Os tubarões de profundidade são especialmente susceptíveis à sobre-pesca, com colapsos populacionais a puderem ocorrer mesmo com níveis baixos de pesca. Duas espécies de tubarão lanterna são normalmente capturadas nas pescarias comerciais que operam na costa sul de Portugal, nomeadamente Etmopterus spinax e E. pusillus. Devido ao seu reduzido ou nulo valor comercial, estas espécies são normalmente rejeitadas, existindo assim uma lacuna nos conhecimentos relativos à sua pesca e biologia. O presente estudo focou aspectos relativos à pesca, morfologia, ciclo de vida, distribuição e dinâmica populacional destas espécies. As pescarias comerciais estão a ter um impacto significativo nestas espécies, com diferentes artes a afectarem de modo diferente as várias componentes das populações, incluindo áreas criticas como zonas de acasalamento e de nascimento. Pela análise multi-variada foi possível separar estas espécies muito semelhantes, sendo criado um modelo que poderá ser utilizado em estudos futuros para mais facilmente separar as espécies. Os parâmetros do ciclo de vida, especificamente idade, crescimento, fecundidade, maturidade e sazonalidade reprodutiva foram estimados e incorporados em modelos de mortalidade e de análise demográfica. Os resultados indicam que a pressão pesqueira actual na costa sul de Portugal não é sustentável e que as populações estão em declínio. Medidas urgentes de conservação são necessárias. Palavras-chave: ciclo de vida; dinâmica populacional; gestão; pescas; águas profundas; tubarões. - 3 - - 4 - Support Support This study was funded by Programa Operacional Ciência e Inovação 2010 (POCI 2010) and Fundo Social Europeu (FSE) through a PhD grant given by Fundação para a Ciência e Tecnologia (FCT) to the candidate Rui Coelho (Ref. SFRH/BD/10357/2002). Apoio Este estudo recebeu o apoio do Programa Operacional Ciência e Inovação 2010 e do Fundo Social Europeu (FSE), através de uma bolsa de Doutoramento concedida pela Fundação para a Ciência e Tecnologia (FCT) ao candidato Rui Coelho (Ref. SFRH/BD/10357/2002). Fundo Social Europeu - 5 - - 6 - Acknowledgments Acknowledgments Along these years several people have, in different ways, contributed to this thesis. Without them, this work would have been impossible to accomplish. Special thanks are therefore acknowledged to: My supervisor Prof. Dr. Karim Erzini at the University of Algarve, for all the support, advice and trust he has given me during these years. Dr. Karim Erzini was an excellent supervisor, always available with wise recommendations and excellent ideas on how to improve this work. The “Coastal Fisheries Research Group” at the University of Algarve, whose members have not only been excellent work colleagues but also true friends. Special thanks go to Dr. Jorge Gonçalves, Luís Bentes and Pedro Monteiro, whose advice and support along these years has been fundamental for the development of this thesis. Further thanks are extended to Joaquim Ribeiro, Frederico Oliveira, Cheila Almeida, David Abecasis, Pedro Veiga, Humberto Hazin and Daniel Machado for providing an excellent work environment and a constant good mood in our office at the University. All commercial fishermen who collaborated in collecting samples for this work. Most of the samples for the biological study came from commercial fisheries and the collaboration from fishermen was crucial. Many commercial vessels and fishermen collaborated in collecting samples and special thanks go to Ilídio Diogo and Francisco Diogo, skippers of the longliner “Branca Sagres”; Helder Cavaco, skipper of the crustacean trawler “Gamba” and the fish trawler “Lestia”; João Paulo, skipper of the - 7 - Acknowledgments trawler “João Pinto”; Lino, ship-owner of the longliner “Luz da Aurora” and José Santos, skipper of the bottom trawler “Crustáceo”. Dr. Ivone Figueiredo and Pedro Bordalo Machado at the “Portuguese Fisheries Research Institute (INIAP – IPIMAR)” for being extremely supportive during this work and starting some cooperation initiatives that will hopefully continue in the future. Javier Rey and Dr. Luís Gil de Sola at the Spanish Institute of Oceanography in Malaga, for allowing me to participate in this institute’s MEDITS (Mediterranean Trawl Survey) campaign, aboard the research vessel “Cornide de Saavedra”. Prof. Dr. Manuel Afonso-Dias at the University of Algarve, for giving me a thorough explanation on the use of the MONICAP system, and whose valuable comments were used in Chapter 6 of this thesis. The staff at the Sagres fish market and landing site, especially the veterinarian Carla and the technician Nuno for helping with the initial contacts with the local fishermen. João Neiva, initially my first undergraduate student and now a good friend, for all the help he gave me during the laboratory biological sampling procedures. Patrícia Tello for having drawn and allowing me to use the scientific drawing of Etmopterus spinax and the Etmopterus head detail that is shown in the cover. Frederico Oliveira for creating the amazing design of the cover of this thesis. The APECE (The Portuguese Association for the Study and Conservation of Elasmobranchs), and especially to Dr. João Correia for all the support along the years. All the student volunteers who along these years have collaborated in the laboratory work. Special thanks go to Joana Fernandez de Carvalho, João Tiago Tavares, Margarida Corado and