4 research outputs found

    Ecological and environmental controls on the fine-scale distribution of cold-water corals in the North-East Atlantic

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    This thesis integrated acoustic, high-definition video and hydrodynamic data to study the distribution, morphology and ecology of cold-water corals (CWC) in the Mingulay Reef area (Chapter 2), the Tisler Reef area (Chapter 3) and the Logachev Mound area (Chapter 4). A new British Geological Survey (BGS) ArcGIS seabed mapping toolbox was developed and quantified semi-automatically the morphometric and acoustic characteristics of CWC reefs. Over 500 Lophelia pertusa reef mounds were delineated and characterised at the Mingulay Reef Complex (Chapter 2), 14 at the Tisler Reef (Norway) (Chapter 3) and 123 in the Logachev Area (Chapter 4). These reefs all had large amounts of small round-shaped mounds. Additionally, the Logachev area had very large dendriform-shaped mounds. A microbathymetric grid of the central area of the Mingulay Reef was used to identify individual live coral colonies (1-7 m) that provided data to predict the likelihood of presence of live coral colonies on biogenic reef mounds (Chapter 2). The distribution and morphology of L. pertusa colonies and the sponges Mycale lingua and Geodia sp. within the Tisler Reef, revealed the importance of local hydrodynamics and substrate availability (Chapter 3). Non-scleractinian corals associated with the Logachev mounds (Chapter 4) proved to be abundant, biodiverse and function as a habitat for associated organisms. Differences in their distribution were found to be related to food supply, the availability and stability of settling substrates. This thesis showed that the BGS Seabed Mapping Toolbox is useful to study the ecology and morphology of reef mounds within and between reefs. Studies on the fine-scale spatial distribution of corals within reefs provided information on the ecology of CWC

    Renaissance in Fisheries: Outlook and Strategies - Book of Abstracts 9th Indian Fisheries Forum, December 19-23, 2011, Chennai, India

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    The Asian Fisheries Society – Indian Branch (AFSIB) since its inception in 1986, has been providing a platform for discussion at the national level on issues related to research, development, education and policies by organizing Indian Fisheries Forum (IFF) every three years in different parts of the country. The 9th Indian Fisheries Forum (9th iff) will be hosted by the Central Marine Fisheries Research Institute (CMFRI), at Chennai during 19-23 December 2011. The main theme of the 9th iff is “Renaissance in Fisheries: Outlook & Strategies”. It would have a comprehensive look for the fisheries and aquaculture sectors, for achieving greater synergy among the stakeholders and planning strategies for capture fisheries and aquafarming to build higher levels of sustainability and profitability. The forum would also address the issues of impact of climate change and its mitigation, resource constraint and species diversification for the expansion of fish production activity; and encourage young scientists to undertake need-based and resource specific research. An international symposium sponsored by the Bay of Bengal Large Marine Ecosystem (BoBLME) is scheduled to be held during the forum on 21 December, 2011 with theme: Bay of Bengal–Ecosystem Approach to Fisheries Management

    Interactions of elasmobranchs with other taxa in Iberian waters: parasitism and agonistic relationships

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    Esta tesis doctoral está dedicada al estudio de las comunidades de helmintos parásitos en elasmobranquios que se encuentran en aguas ibéricas, tanto en el Atlántico como en el Mediterráneo, con comentarios sobre las relaciones agonísticas entre la tintorera (Prionace glauca) y el pez espada (Xiphias gladius), cuestiones que no habían no ha sido abordadas antes por otros investigadores. El presente estudio proporciona, por primera vez, un informe cuantitativo sobre la fauna de cestodos en cuatro especies de elasmobranquios, el tiburón marrajo dientuso (Isurus oxyrinchus); la tintorera (Prionace glauca); la tremielga, (Torpedo marmorata), y el torpedo común (Torpedo torpedo), en aguas ibéricas (Atlántico nororiental, Galicia; Mediterráneo occidental, Valencia). También investiga el papel de los rasgos específicos de la especie hospedadora para proporcionar estructura a nivel infracomunitario. Este estudio también documenta interacciones agonísticas inesperadas, pero cada vez más descritas, entre tiburones azules y peces espada (Xiphias gladius) en los últimos años, discutiendo su significado funcional e impacto en la población. En general, esta tesis muestra cómo las comunidades de parásitos de elasmobranquios se han descuidado en el pasado, cómo sus infracomunidades están afectadas por la filogenia, las características ecológicas y particulares del hospedador, y brinda puntos de referencia para estudios futuros. Además, al señalar la falta de estudios ecológicos parasitarios de los elasmobranquios, hace un llamamiento al desarrollo de este campo de investigación, demostrando que sería beneficioso para mejorar el conocimiento actual tanto de los parásitos de elasmobranquios como de sus hospedadores, con la esperanza de contribuir en su conservación y al adecuado desarrollo de este campo.This doctoral thesis is devoted to the study of parasite helminth communities in elasmobranchs found in Iberian waters, both in the Atlantic and the Mediterranean, with comments on the agonistic relationships between blue sharks (Prionace glauca) and swordfish (Xiphias gladius), questions that hadn't been approached before by previous researchers. The present study provides, for the first time, a quantitative report on the cestode fauna in four elasmobranch species, i.e., the shortfin mako shark (Isurus oxyrhinchus); the blue shark (Prionace glauca); the marbled electric ray, (Torpedo marmorata), and the common torpedo (Torpedo torpedo), in Iberian waters (Northeastern Atlantic, Galicia; Western Mediterranean, Valencia). It also investigates the role of key host species-specific traits in providing structure at infracommunity level. This study also documents unexpected, but increasingly noticed, agonistic interactions between blue sharks and swordfish (Xiphias gladius) over recent years, discussing their functional meaning and population impact. Overall, this thesis shows how parasite communities of elasmobranchs have been mostly neglected in the past, how their infracommunities are driven by phylogeny, ecological and particular host's traits, and gives points of reference for future studies. Also, by pointing out the lack of ecological parasitic studies of elasmobranchs, it makes a call towards the development of this research field, proving that it would be beneficial for improving the current knowledge of both elasmobranch parasites and their host, hopefully contributing to their proper conservation and making sure they are worthily validated