14 research outputs found

    Improving fisheries management through spatio-temporal analysis of catches, discards, fishing effort and selectivity, across different métiers

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    I would first like to thank my advisers, especially Dr. Karim Erzini for helping me with the project change during the first of the PhD and for overall support since the beginning of my master‚Äôs project. I deeply admire your passion for fisheries research and the number of hours you have spent reviewing my writing. Thank you to Dr. Aida Campos for giving me an opportunity to expand my horizons in fisheries when I joined the TecPescas project and for support in and outside the PhD. Thank you to Dr. Jorge Gon√ßalves for the local support during the PhD, especially for helping me learn how to take care of the financial side of science. Finally, a thank you to Dr. Svein L√łkkeborg in Norway for the original opportunity to collaborate with him prior to my change in the project and for the support during writing my first review. Thank you to all the fishers I worked with, and we interviewed for giving me the data that I needed to complete this PhD. A special thanks to the captain and crew of Mar Vivo, for a very wild experience on the sea and delicious fresh lunches. And to the captain and crew of Bartolomeu who worked with us on the trammel net project as I thoroughly enjoyed the dinners that I received from them and due to all of them being extremely friendly. A thank you to all my colleagues who worked with me at various periods of the PhD. Without your support I could not have finished my work. Thank you to Mariana Fernandes, Ana Mar√ßalo and especially Pedro Monteiro for helping me grow as a researcher from the master‚Äôs until now. Thank you to all the people of Fisheries, Biodiversity and Conservation lab for all the help, for creating a general environment of friendliness and for making time to chat. Thank you so much to all my friends and to my husband that have also been there for me throughout the PhD. From getting coffees in the morning, to lunches in the afternoon, to those who were there from the beginning and to those I met later in the PhD program, as well as those who I‚Äôve known from 6 to 15 years and have supported my dreams in science. Thank you to my parents who have supported my journey in science since I decided I was going to do a PhD in marine biology when I was only 13 years old. Thank you for the sacrifices you both made and for being role models in what hard and efficient work can mean, as well as taking pride in your work. Thank you to my sister who has been my cheerleader through the past years and especially during my periods of struggle, I am extremely thankful to have a sibling who cares so much to see me succeed. Thank you to my grandma for getting on skype almost every weekend and to my grandpa for making me laugh. (PL: Dzińôkujńô mojej babci za to, Ňľe prawie w kaŇľdy weekend wchodziŇāa na skype i sŇāuchaŇāa mnie i mojemu dziadkowi za rozŇõmieszenie mnie.) Fishers in the Southern Portuguese multi-gear coastal fleet own licenses for a variety of fishing gears including static nets, longlines, and traps, and dredges. Information on the fishing gear being actively used is scarce and most vessels are not required to report geographic location, making the impact of the local environment difficult to evaluate. The first and main objective of this thesis was to identify m√©tiers in the multi-gear coastal fisheries operating in the Portuguese south coast, including the type of gear being used to target specific species or assemblages in certain areas during a specific time of year in a three-step process. The first step was a review to understand the definition of fisheries m√©tiers using static longlines due to their well-defined target species, little environmental impacts, and various characteristics that can be modified for improved fishing. This was followed by a cluster analysis on landing profiles for the fleet (2012-2016), followed by the second and third step in which validations using questionnaires and onboard observations, respectively. The main finding was the application of a low-cost analysis to identify m√©tiers within a multi-gear fleet with limited data, and specific to this fleet, an increasing number of vessels active within the octopus (Octopus vulgaris) trap m√©tier. The second objective was to assess a proposed raised trammel net (by insertion of a section referred to as ‚Äúaranha‚ÄĚ) to reduce by-catch and habitat impacts in the cuttlefish (Sepia officinalis) trammel net fishery. The results were promising as the modified net caught significantly less habitat forming organisms and similar target species‚Äô amounts as the standard net. The results presented in this thesis can contribute to the management of this multi-gear fleet by presenting the necessary information to make decisions, especially for m√©tiers with high number of vessels, and effort in highlighting the necessity for gear modifications in areas where the habitat is impacted.As embarca√ß√Ķes da frota costeira polivalente que opera na costa sul portuguesa possuem geralmente v√°rias licen√ßas de pesca, incluindo redes de emalhar e de tresmalho, armadilhas, potes (alcatruzes), palangres de deriva e de fundo, e dragas. A informa√ß√£o existente sobre as artes efetivamente utilizadas e as √°reas de opera√ß√£o √© escassa, pois s√≥ um n√ļmero muito reduzido de embarca√ß√Ķes nesta frota est√° equipada com o sistema de monitoriza√ß√£o das pescas (MONICAP e di√°rios eletr√≥nicos de pesca). Uma vez que a utiliza√ß√£o de artes distintas resulta em grandes diferen√ßas quer na composi√ß√£o das capturas, quer nos efeitos sobre os diferentes habitats, √© dif√≠cil avaliar o impacte desta frota sobre o ecossistema onde opera. O primeiro e principal objetivo desta tese foi identificar os m√©tiers desta frota, incluindo as artes de pesca utilizadas em determinadas √°reas ao longo do ano e as esp√©cies capturadas por estas artes. Para responder a este objetivo foi adotada uma abordagem em quatro etapas sequenciais (Cap√≠tulos 2 a 6). A primeira etapa visou melhorar a compreens√£o sobre o conceito de m√©tier, atrav√©s da revis√£o bibliogr√°fica sobre os principais par√Ęmetros operacionais que podem afetar as capturas em palangres de fundo e semi-pel√°gicos, artes de pesca consideradas altamente seletivas, ambas utilizadas pela frota polivalente costeira. A revis√£o bibliogr√°fica (Cap√≠tulo 2) resultou na defini√ß√£o das caracter√≠sticas destas artes (tipo e tamanho do de anzol) e estrat√©gias de pesca (tipo de isco e tempo de imers√£o) associadas a diversos m√©tiers. Concluiu-se que a utiliza√ß√£o de anz√≥is circulares melhora a seletividade e a efici√™ncia de captura em diversas pescarias com esta arte, enquanto que o tempo de imers√£o n√£o afetar√° de modo significativo estas caracter√≠sticas, embora isso possivelmente se deva ao fato de ser um par√Ęmetro mascarado por outros par√Ęmetros. Os resultados contribuem para futuros estudos que tenham como objetivo otimizar as estrat√©gias de pesca com esta arte e melhorar a efici√™ncia de captura. A segunda etapa (Cap√≠tulo 3) envolveu a utiliza√ß√£o de t√©cnicas de an√°lise multivariada (Clustering Large Aplications, CLARA) com o objetivo de definir os perfis de desembarque para esta frota entre 2012 e 2016, identificando as principais esp√©cies-alvo, bem como poss√≠veis altera√ß√Ķes sazonais na composi√ß√£o das capturas e ainda propondo, com base em conhecimento pr√©vio, as artes de pesca utilizadas. A terceira etapa (Cap√≠tulo 4) foi dedicada √† valida√ß√£o dos m√©tiers propostos por meio de inqu√©ritos/entrevistas nos portos, utilizando dois question√°rios, o primeiro contendo quest√Ķes abertas sobre as caracter√≠sticas da viagem e das artes de pesca utilizadas, incluindo perguntas sobre as esp√©cies-alvo, enquanto que o segundo visou a associa√ß√£o entre esp√©cies-alvo e opera√ß√Ķes de pesca em perguntas fechadas. A compara√ß√£o das respostas nos dois question√°rios permitiu avan√ßar na identifica√ß√£o dos m√©tiers. Na quarta etapa (Cap√≠tulo 5) procedeu-se a uma valida√ß√£o adicional dos m√©tiers atrav√©s de observa√ß√Ķes a bordo, onde foi registada a composi√ß√£o das capturas, juntamente com os detalhes e a localiza√ß√£o geogr√°fica das opera√ß√Ķes de pesca nos m√©tiers amostrados. Os resultados dos Cap√≠tulos 3 a 5 apontam para a relev√Ęncia de uma pescaria dirigida ao polvo (Octopus vulgaris) com alcatruzes e armadilhas, durante todo o ano, a profundidades at√© aos 100 metros, tendo sido definido um conjunto de esp√©cies acess√≥rias numa pescaria anteriormente conhecida como sendo mono-espec√≠fica. Outros m√©tiers importantes s√£o a pescaria do tamboril (Lophius spp.) com redes de emalhar, no per√≠odo do inverno ao ver√£o, a profundidades at√© 400 metros; e da pescada branca (Merluccius merluccius) e a azevia (Microchirus spp.), tamb√©m com redes de emalhar, durante todo o ano, a profundidades at√© 100 e 50 metros, respetivamente, com capturas acess√≥rias mais reduzidas quando comparadas com as capturas reportadas em estudos anteriores sobre estes m√©tiers. Os bivalves, incluindo o p√©-de-burrinho (Chamelea gallina), a am√™ijoa-branca (Spisula solida) e as conquilhas Donax spp, s√£o capturados com ganchorras, durante todo o ano. Por fim, o choco (Sepia oficinallis) e a canilha (Bolinus brandaris) s√£o capturados com tresmalhos, o primeiro no inverno e na primavera e a segunda durante todo o ano. Estes resultados permitiram validar m√©tiers propostos em estudos anteriores, embora os nossos resultados indiquem que mais de metade das embarca√ß√Ķes se encontram envolvidas na captura de polvo, tendo alterado as suas licen√ßas de pesca para incluir alcatruzes e armadilhas durante o per√≠odo em an√°lise. De um modo geral, as embarca√ß√Ķes que operam redes alternam sazonalmente entre tresmalhos e redes de emalhar. No Cap√≠tulo 5, procedeu-se a uma caracteriza√ß√£o mais aprofundada de alguns dos m√©tiers propostos, tendo sido identificados alguns m√©tiers adicionais envolvendo um n√ļmero reduzido de embarca√ß√Ķes. Um segundo objetivo desta tese (Cap√≠tulo 6) foi propor e testar modifica√ß√Ķes √†s artes para reduzir capturas acess√≥rias e impactes negativos no ecossistema, concretamente na pesca de choco (Sepia officinalis) com redes de tresmalho, em √°reas com fundos rochosos, onde as capturas acess√≥rias de invertebrados s√£o elevadas. As altera√ß√Ķes √† rede tradicionalmente utilizada consistiram na introdu√ß√£o de uma sec√ß√£o entre os panos de rede e o cabo dos chumbos, √† qual os pescadores chamaram ‚Äúaranha‚ÄĚ, e que permitiu levantar a rede do fundo. Os resultados apontam para uma redu√ß√£o dos principais invertebrados (incluindo esponjas, corais, pepinos-do-mar e estrelas-do-mar), com altera√ß√Ķes n√£o significativas na captura das duas principais esp√©cies-alvo, o choco e a azevia. As entrevistas que foram feitas ap√≥s a an√°lise permitiram recolher opini√Ķes dos pescadores sobre a utilidade de uma futura implementa√ß√£o das altera√ß√Ķes propostas, tendo oferecido uma solu√ß√£o que poder√° ser testada no futuro. Os resultados apresentados nesta tese fornecem uma base para a identifica√ß√£o de m√©tiers atrav√©s de uma abordagem que envolve tr√™s etapas sequenciais. A informa√ß√£o obtida com a an√°lise das atividades desta frota pode ser utilizada para avaliar o impacte no meio ambiente local de acordo com as artes de pesca efetivamente utilizadas. Os diferentes m√©todos de entrevista devem tamb√©m ser considerados e, para fins futuros, os dois formul√°rios utilizados podem ser reunidos num √ļnico formato. No entanto, reconheceu-se que a segunda rodada de question√°rios foi mais √ļtil, pois forneceu respostas mais diretas √†s quest√Ķes colocadas aos pescadores. Curiosamente, os resultados obtidos relativamente √†s rejei√ß√Ķes ao mar foram diferentes daqueles esperados para as embarca√ß√Ķes que operam com armadilhas e redes. Os resultados apresentados nesta tese podem ser utilizados na gest√£o desta frota polivalente, voltando potencialmente a aten√ß√£o para o segmento da frota que visa o polvo, uma vez que este m√©tier envolve mais de metade das embarca√ß√Ķes ativas desta frota. Al√©m disso, os ensaios de pesca experimental podem ajudar a gest√£o a avaliar os impactos das artes est√°ticas nas esp√©cies formadoras de habitat e, ao apoiar futuros estudos com foco na captura acidental desses organismos, reduzir os impactos negativos da atividade da pesca.The primary data, landings by vessel, were provided by the Directorate-General for Natural Resources, Safety and Maritime Services (DGRM) and the DocaPesca Portos e Lotas SA of Portugal. The bottom sediment chart was accessed through Observation Data Network (EMODnet), Seabed Habitats initiative (www.emodnet-seabedhabitats.eu), financed by the European Union under Regulation (EU) No 508/2014 of the European Parliament and of the Council of 15 May 2014 on the European Maritime and Fisheries Fund. The remainder of the data used in this thesis was collected by the author with her colleagues within the framework of the project ‚ÄúTecPescas ‚Äď Tecnologia da Pesca e Seletividade‚ÄĚ (Mar2020 16-01-04-FMP-0010 ‚Äď IPMA)

    Coastal fishes of the western Indian Ocean

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    The primary purpose of this book is to provide a means of identifying the more than 3 200 species of coastal fishes known to occur in the Western Indian Ocean (WIO). Coastal fishes are those that inhabit waters generally less than ~200 m deep, the waters over continental and insular shelves, and upper continental slopes. The book also includes some oceanic species and species that live in deeper water, but are sometimes caught in trawls in less than 200 m, or that migrate into shallower waters at night to feed. The Western Indian Ocean (WIO), as treated in these volumes, is the area between Cape Point, South Africa, and 77¬į34' E, at Kanyakumari (formerly Cape Cormorin), the southernmost point of India, and to 40¬į S, just south of St Paul Island. Although considered as separate water bodies, the Red Sea and Persian/Arabian Gulf have been included. Some contributors have also chosen to include species from Sri Lanka. The region thus encompasses the entire east and southern coasts of Africa, Madagascar and the various island clusters of the Comoros, the Seychelles, the Maldive and Lakshadweep islands, the Chagos Archipelago and the islands and sea mounts of the Mascarene Plateau, to as far as 40¬į S, and thus some fishes from St Paul and Amsterdam Islands have been included. This large expanse, stretching from tropical waters of the northwestern Indian Ocean to the warm temperate waters of False Bay, South Africa, includes a number of poorly known biogeographic areas. A map of the entire Indian Ocean is placed on the inside front cover of each printed volume, with some areas in greater detail on the inside back cover. The book does not include distribution maps for species, but gives localities from which species are known, with emphasis on WIO localities; our understanding of distributions of many species is often incomplete. Fishes are the most abundant and diverse group of vertebrates and have colonised every aquatic habitat on Earth: the oceans, lakes, rivers and caves, from polar seas at ‚Äď2 ¬įC to hot, freshwater springs at 44 ¬įC, and from tropical reefs and mangrove forests to the deepest ocean depths. Fishes are also the most poorly known group of vertebrates. In the 2006 edition of Joseph Nelson‚Äôs Fishes of the World the estimate of the number of species of extant fishes worldwide stood at about 23 000. This number is growing annually, and was thought to be about 33 460 species at the end of 2016 (www.fishwisepro.com). Between the years 2000 and 2015 an average of 150 new species of marine fishes were described each year ‚Äď of which 10% of the total (156 species) were from the WIO. The WIO is home to about 15% of all the marine fish species in the world‚Äôs oceans. Another measure of the diversity of fishes of this area is its relatively high level of endemicity, particularly around southern Africa and in the Red Sea. About 13% of southern African marine fishes are endemic, most of these in only five families: Clinidae with about 44 endemic species, Gobiidae with 28, Sparidae with 28, Pentanchidae with 6, and Batrachoididae with 7 endemic species. In the Red Sea at least 170 of the more than 1100 species are endemic. The WIO region is also home to a large human population, representing a wide range of ethnic and cultural backgrounds. The area includes the countries of South Africa, Mozambique, Tanzania, Kenya, Somalia, Eritrea, Sudan, Egypt, Israel, Jordan, Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, Iran, Pakistan, India and Sri Lanka, as well as the many island nations and territories. Many of the people living in coastal areas are dependent on fish catches and other marine resources for both sustenance and often a livelihood, as highly diversified artisanal fisheries make up the bulk of the fishing effort in the region. And, as elsewhere in the world, many of the fish resources have been compromised by commercial interests (including those of other countries), often leaving fish stocks in a poor state. This book has a number of purposes, all of which coalesce around providing users with a better understanding of the area‚Äôs fishes and their environment. Accordingly, it includes a number of background chapters covering subjects as diverse as the oceanography of the region, and the history and evolution of the bony fishes. In recent years genetic analysis has proved to be a powerful tool for taxonomists. In many instances molecular results have caused taxonomists to rethink both the definitions of certain taxa and the interrelationships of taxa. In some instances, what were long considered cohesive (monophyletic) taxa were found to include groups of fishes that are in fact not closely related (paraphyletic), while in other instances taxa thought to be distinct were found not to be, meriting their merging with other existing taxa. At times, long-accepted family groups have been divided into two or more distinct families, or separate families have been combined into a single one. Where possible such changes in our understanding of the relationships of fishes are reflected in these volumes. Where some contributors have taken a more conservative approach by awaiting more research and not adopting these changes, alternative taxonomies are noted (see also the introductory chapter on Naming organisms and determining their relationships). For each species in the book, the literature pertinent to that species in the WIO is given: the original species description reference, synonyms for the region and other important taxonomic and biological references. For many commercially important species or fishes of interest to anglers there is additional information on life history, size and capture, and for some but not all species, their IUCN conservation status if Near Threatened, Vulnerable, Endangered or Critically Endangered (in the first instance, valid at the time of writing. See www.iucnredlist.org for current information. Note: we have not included the IUCN conservation status where species are of Least Concern or Data Deficient). Most species are illustrated with photographs, drawings or paintings. Colour photographs and paintings are provided on plates for each volume.1st Editio

    Seamount seascape composition and configuration shape Southwest Indian Ridge fish assemblages

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    Seamounts are commercially important fishing grounds. Yet, little is known about their physical characteristics as fish habitat, important for informing conservation and ecosystem-based management. This study examines how multiscale seabed spatial heterogeneity influences commercially important fish families at three Southwest Indian Ridge seamounts (Coral Seamount, Melville Bank and Atlantis Bank). We quantified seascape heterogeneity from bathymetry and geomorphological habitat maps and identified 15 focal fish families from video data. Fish-habitat associations were examined using spatial pattern metrics that measured terrain morphology, seascape composition (variety and relative abundance of patch types) and seascape configuration (spatial arrangement of patches). Broader seascape context was characterised by geographic location and water depth. Multivariate regression trees and random forests modelled fish-habitat associations and identified the most influential explanatory variables. Assemblage characteristics and individual families were strongly influenced by geographic location and depth, and at finer scales (500 m buffers) seascape composition and configuration helped explain fish-habitat associations. Spatially continuous summit habitat and complex shaped ridge features supported high abundance and diversity of commercial fish families. Metrics of seascape composition and configuration (i.e., habitat size, shape and structural connectivity) had higher predictive power than the terrain metrics commonly used in developing proxies for deep-water fish species and biodiversity. These outcomes indicate that seascape metrics, commonly applied on land and in shallow marine environments, are also relevant environmental predictors of fish distributions in deep-sea environments. We highlight strong context dependency and depth-specific associations that hinder attempts to draw wider generalisations on fish-seascape linkages for seamounts

    Microplastic in the stomachs of open-ocean and deep-sea fishes of the North-East Atlantic

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    This is the author accepted versionThe presence of microplastic in marine fishes has been well documented but few studies have directly examined differences between fishes occupying contrasting environmental compartments. In the present study, we investigated the gut contents of 390 fishes belonging to three pelagic (blue jack mackerel, chub mackerel, skipjack tuna) and two deep-sea species (blackbelly rosefish, blackspot seabream) from the Azores archipelago, North-East Atlantic for microplastic contamination. Our results revealed that pelagic species had significantly more microplastic than the deep-water species. In all of the species studied, fragments were the most common plastic shape recovered and we found a significant difference in the type of polymer between the pelagic and deep-water species. In deep-sea fish we found almost exclusively polypropylene, whereas in the pelagic fish, polyethylene was the most abundant polymer type. Overall, the proportion of fish containing plastic items varied across our study species from 3.7% to 16.7% of individuals sampled, and the average abundance of plastic items ranged from 0.04 to 0.22 per individual (the maximum was 4 items recovered in one stomach). Despite the proximity of the Azores archipelago to the North Atlantic subtropical gyre, a region of elevated plastic abundance, the proportion of individuals containing plastic (9.49%) were comparable with data reported elsewhere.Natural Environment Research Council (NERC

    Updated checklist of bony fishes along the Libyan coasts (Southern Mediterranean Sea)

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    Here we provide an updated review of both native and non-indigenous ichthyofauna occurring in the waters of Libya, one of the largest and less studied marine areas of the Mediterranean basin. With respect to the most recent information, the list of Libyan bony fishes was updated with 104 species for a total of 304 listed taxa. Out of these species, 271 are native, 6 endemic to the Mediterranean, 22 non indigenous of Lessepsian origin and 5 range expanding taxa from Gibraltar. Information on the distribution and abundance of Lessepsian fishes along the Libyan coasts was gained through both field surveys and interviews with local small-scale fishermen, which contributed in filling large information gaps in the area. This combined approach allowed to gather a more complete representation of non indigenous species along the Libyan coasts and indicated three assessment areas, corresponding to the eastern, central and western sectors of the country, which should be considered in future monitoring programs

    Regional differences in the feeding of the ambush predator Neosebastes pandus and comparisons of diets in the Scorpaenidae, Triglidae and Platycephalidae

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    This study provides a comprehensive assessment of the dietary composition of the ambush predator Neosebastes pandus and compares the diets of 49 species from 39 studies of three benthic predatory families in the Scorpaeniformes: Scorpaenidae (20 species), Triglidae (19 species) and Platycephalidae (10 species). A total of 275 N. pandus were collected from the west (Rottnest Island) and south coasts (Esperance) of south‚Äźwestern Australia and the percentage frequency and volumetric contribution of the stomach contents identified. Fish from the west coast consumed a greater mean number of broad taxonomic groups and were more diverse in their diet than fish from the south coast. Cephalopods, brachyurans and teleosts were the largest overall contributors to diet, with teleosts being more important to diets of west‚Äźcoast fish and polychaetes for south‚Äźcoast fish. This reflects differences in habitat between the two locations. Dietary composition also changed with increasing body size, reflecting morphological changes that allow bigger fish to capture and ingest larger, more mobile prey. Meta‚Äźanalysis of the diets of 49 species of scorpaenid, triglid and platycephalid revealed that they feed predominantly on teleosts and large crustaceans. Significant differences in diet were detected among families, with platycephalids being the most distinct and feeding more on teleosts than scorpaenids and triglids

    Manual de identificação de peixes ósseos da costa continental portuguesa : Principais características diagnosticantes

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    Este trabalho √© um manual pr√°tico para identifica√ß√£o de peixes √≥sseos, que ocorrem na costa continental portuguesa, com base em caracteres diagnosticantes que, de forma f√°cil, permitem distingui-los. Apresenta-se por esp√©cie, um esquema com a indica√ß√£o da localiza√ß√£o das principais carater√≠sticas e, em anexo, sempre que poss√≠vel, a fotografia. As descri√ß√Ķes permitem diferenciar as esp√©cies com interesse comercial e ou submetidas a medidas t√©cnicas de gest√£o, de outras morfologicamente semelhantes, mas que n√£o t√™m a mesma import√Ęncia, quer comercial quer a n√≠vel de gest√£o. S√£o descritas sumariamente 150 esp√©cies, indicando os seus nomes vulgares em diversas l√≠nguas e o respetivo c√≥digo FAO. S√£o tamb√©m inclu√≠das duas esp√©cies de cicl√≥stomos pelo seu interesse comercial e por apresentarem caracter√≠sticas morfol√≥gicas distintas.info:eu-repo/semantics/publishedVersio

    Marine Biodiversity and Ecosystem Health of Ilhas Selvagens, Portugal

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    In September 2015, National Geographic's Pristine Seas project, in conjunction with the Instituto Universit√°rio-Portugal, The Waitt Institute, the University of Western Australia, and partners conducted a comprehensive assessment of the rarely surveyed Ilhas Selvagens to explore the marine environment, especially the poorly understood deep sea and open ocean areas, and quantify the biodiversity of the nearshore marine environment

    Habitat predictive modelling of demersal fish species in the Azores

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    Disserta√ß√£o de Mestrado, Estudos Integrados dos Oceanos, 25 de Mar√ßo de 2013, Universidade dos A√ßores.Species distribution modelling of the marine environment has been extensively used to assess species‚Äďenvironment relationships to predict fish spatial distributions accurately. In this study we explored the application of two distinct modelling techniques, maximum entropy model (MaxEnt) and generalized linear models (GLMs) for predicting the potential distribution in the Azores economic exclusive zone (EEZ) of four economically important demersal fish species: blackbelly rosefish, Helicolenus dactylopterus dactylopterus, forkbeard, Phycis phycis, wreckfish, Polyprion americanus and offshore rockfish, Pontinus kuhlii. Models were constructed based on 13 years of fish presence/absence data derived from bottom longline surveys performed in the study area combined with high resolution (300 m) topographic and biogeochemical habitat seafloor variables. The most important predictors were depth and slope followed by sediment type, oxygen saturation and salinity, with relative contributions being similar among species. GLMs provided ‚Äėoutstanding‚Äô model predictions (AUC>0.9) for two of the four fish species while MaxEnt provided ‚Äėexcellent‚Äô model predictions (AUC=0.8‚Äď0.9) for three of four species. The level of agreement between observed and predicted presence/absence sites for both modelling techniques was ‚Äėmoderate‚Äô (K=0.4‚Äď0.6) for three of the four species with P. americanus models presenting the lowest level of agreement (K<0.1). For the scope of this study, both modelling approaches presented here were determined to produce viable presence/absence maps which represent a snap‚Äďshot of the potential distributions of the investigated species. This information provides a better description of demersal fish spatial ecology and can be of a great deal of interest for future fisheries management and conservation planning
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