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| Registros recuperados: 10 | |
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| Gaertner, Jean-claude; Merigot, Bastien; Relini, Giulio; Bertrand, Jacques; Mazouni, Nabila; Politou, Chrissi-yianna; Gil De Sola, Luis; Kallianiotis, Argyris; Carpentieri, Paolo; Murenu, Matteo; Durbec, Jean-pierre; Vrgoc, Nedo; Ungaro, Nicola. |
| Recent theoretical and field studies conducted in both terrestrial and marine ecosystems have suggested that diversity could be a more complex and multi-component concept than previously thought. However, it is still poorly understood to what extent the information provided by the various indices is complementary with regard to diversity, and to what extent this complementarity is reproducible in different situations or at different scales of observation. In the present work, we have analysed the reproducibility of the empirical relationships between 11 diversity indices related to four major aspects (components) of species diversity (species richness, rarity, evenness and species taxonomy) in order to determine whether there is a general pattern of... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00029/14064/11382.pdf |
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| Bertrand, Jacques; Souplet, Arnauld; Gil De Sola, Luis; Relini, Giulio; Politou, Chrissi-yianna. |
| This document is the fifth version of a manual elaborated in the frame of an international project to harmonise the samplings by bottom trawling of the demersal resources in the Mediterranean Sea (MEDITS program). It is the reference document for the surveys to be conducted from 2007 onwards by the research institutes contributing in the Medits surveys on the continental shelves and slopes in the Mediterranean (Fig. 1). The manual describes the sampling gear characteristics, the sampling methodology and the treatment of the samples. Finally it gives the specifications of the data files for data storage and exchange. |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00002/11321/7850.pdf |
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| Large, Philip A.; Agnew, David J.; Alvarez Perez, Jose Angel; Barrio Frojan, Christopher; Cloete, Rudi; Damalas, Dimitrios; Dransfeld, Leonie; Edwards, Charles T. T.; Feist, Stephen; Figueiredo, Ivone; Gonzalez, Fernando; Gil Herrera, Juan; Kenny, Andrew; Jakobsdottir, Klara; Longshaw, Matt; Lorance, Pascal; Marchal, Paul; Mytilineou, Chryssi; Planque, Benjamin; Politou, Chrissi-yianna. |
| Scientific interest in deep-water marine resources has increased dramatically over the last 10-20 years as management bodies have sought advice on how to manage deep-water fisheries and protect deep-water ecosystems. The strengths and weaknesses of the management and monitoring of deep-water stocks, fisheries, and ecosystems in various areas of the world are described, with the objective of informing the EU FP7 DEEPFISHMAN project so that it can fulfill its primary aim, which is to develop strategic options for a short-and long-term management and monitoring ecosystem-based framework for the northeast Atlantic. To provide a baseline, the current monitoring and management regime in the northeast Atlantic is reviewed, followed by a brief description of the... |
| Tipo: Text |
Palavras-chave: Deep-water; Fisheries; Ecosystem; Monitoring; Management. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00142/25321/24803.pdf |
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| Cotter, John; Petitgas, Pierre; Abella, Alvaro; Apostolaki, Panayiota; Mesnil, Benoit; Politou, Chrissi-yianna; Rivoirard, Jacques; Rochet, Marie-joelle; Spedicato, Maria Teresa; Trenkel, Verena; Woillez, Mathieu. |
| Ideas and considerations are put forward for managing fisheries and marine populations using primarily trawl surveys to supply biological and spatial indicators of the state of stocks, and to permit catch per unit effort (CPUE)-based assessments. Trawl surveys seldom allow absolute estimates of fish population sizes but, if appropriately located, timed, and designed, can provide a broad range of information about catchable fish species and the ecosystem that supports them. This information may be more conducive to sustainable management of fisheries than the traditional focus on the abundances of selected stocks. The paper first briefly proposes how survey-based methods might supplement existing fishery-dependent stock assessments, as would be necessary... |
| Tipo: Text |
Palavras-chave: Fishing effort indicator; Fisheries independent assessment; Survey based stock assessment; Spatial indicator; State indicator; Trawl survey; Fisheries management. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6691.pdf |
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| Rochet, Marie-joelle; Trenkel, Verena; Carpentier, Andre; Coppin, Franck; Gil De Sola, Luis; Leaute, Jean-pierre; Mahe, Jean-claude; Maiorano, Porzia; Mannini, Alessandro; Murenu, Matteo; Piet, Gerjan; Politou, Chrissi-yianna; Reale, Bruno; Spedicato, Maria-teresa; Tserpes, George; Bertrand, Jacques. |
| P>1. The development of ecosystem approaches to environmental management implies the need to account for multiple pressures on ecosystems. Trends in multiple metrics that respond differently to changes in major environmental pressures need to be combined to evaluate the impacts of fishing and environmental changes on fish communities. 2. An exploited fish community is viewed as a three-level food chain in which the two upper levels, or functional groups, are targeted by fishing fleets, while the lowest level is subject to environmental variation. Qualitative modelling is used to predict changes at the two upper levels, that is, top-down vs. bottom-up perturbations. Abundance and length metrics are calculated from survey data for 14 Mediterranean and... |
| Tipo: Text |
Palavras-chave: Bottom-up control; Community metrics; Compensation; Ecosystem approach to fisheries; Ecosystem assessment; Functional groups; Groundfish community; Mediterranean; North Atlantic; Top-down control. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00008/11925/8637.pdf |
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| Tsagarakis, Konstantinos; Mytilineou, Chryssi; Haralabous, John; Lorance, Pascal; Politou, Chrissi-yianna; Dokos, John. |
| Data from the MEDITS bottom trawl surveys in the Eastern Ionian Sea, covering a depth range of 28 to 845 m were analysed for the period 1998-2008. For each trawling location, environmental and geographical parameters were recorded, while biomass, abundance, biodiversity and size-based metrics were estimated for the total megafaunal community, as well as for four taxonomic sub-communities (Osteichthyes, Chondrichthyes, Crustacea and Cephalopoda) which were expected to respond differently to environmental changes and fishing. In addition, biomass and abundance of ten species selected based on commercial interest, depth range and life history traits were explored, with particular emphasis on deep-sea species. Fishing effort data collected during the study... |
| Tipo: Text |
Palavras-chave: Biodiversity; Fisheries impacts; Demersal community; Survey indicators; Temporal trends; Mediterranean Sea. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28761/27230.pdf |
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| Gaertner, Jean-claude; Maiorano, Porza; Merigot, Bastien; Colloca, Francesco; Politou, Chrissi-yianna; Gil De Sola, Luis; Bertrand, Jacques; Murenu, Matteo; Durbec, Jean-pierre; Kallianiotis, Argyris; Mannini, Alessandro. |
| Large-scale studies focused on the diversity of continental slope ecosystems are still rare, usually restricted to a limited number of diversity indices and mainly based on the empirical comparison of heterogeneous local data sets. In contrast, we investigate large-scale fish diversity on the basis of multiple diversity indices and using 1454 standardized trawl hauls collected throughout the upper and middle slope of the whole northern Mediterranean Sea (36 degrees 3' - 45 degrees 7' N; 5 degrees 3'W - 28 degrees E). We have analyzed (1) the empirical relationships between a set of 11 diversity indices in order to assess their degree of complementarity/redundancy and (2) the consistency of spatial patterns exhibited by each of the complementary groups of... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00152/26299/24392.pdf |
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| Woillez, Mathieu; Petitgas, Pierre; Rivoirard, Jacques; Fernandes, Paul; Hoftstede, Remment Ter; Korsbrekke, Knut; Orlowski, Andrzej; Spedicato, Maria-teresa; Politou, Chrissi-yianna. |
| Population dynamics is commonly described non-spatially using parameters of population demography and vital traits. Population spatial organisation is therefore considered implicit and its importance in the population dynamics ignored. The present study evidences on a variety of stocks correlation between population spatial distribution indices, population abundance, recruitment and mortality. Series of research fisheries monitoring surveys were considered for a range of different stocks (cod, herring, anchovy, hake, mullet) in different regions of the North East Atlantic and Mediterranean (North Sea, Barents Sea, Baltic Sea, Bay of Biscay, Tyrrhenian Sea, Ionian Sea and Aegean Sea). For each population, each age and each year, 9 spatial indices were... |
| Tipo: Text |
Palavras-chave: Spatial indices population dynamics; Meta-analysis.. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00133/24376/22388.pdf |
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| Registros recuperados: 10 | |
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