Bycatch of billfishes by the European tuna purse-seine fishery in the Atlantic Ocean

Billfishes are a component of offshore ecosystems; thus it is important to quantify the impact of the tuna fishery on these species in the world’s ocean. The aim of this study was to assess the bycatch of billfishes generated by the tropical tuna purse-seine fishery in the eastern Atlantic Ocean. Information on bycatch was collected by observers at sea during the European Union Bigeye Program. With a total of 62 observers’ trips, conducted on Spanish and French vessels between June 1997 and May 1999, this project is the biggest observer program ever carried out in the European tuna purse-seine fishery. This study showed that billfish bycatch by the purse seiners is very low (less than 0.021% of the total tuna catches and less than 10% of the total billfish catches currently reported). A Monte Carlo simulation was performed to account for some uncertainties in the fishing strategies of purse seiners operating in this ocean. One of the findings of this study indicated that the temporary moratorium on fishing with FADs (fish aggregating devices), adopted by the European purse-seine fishery in the eastern Atlantic Ocean, produced a decrease in incidental catches of marlins from 600–700 metric tons (t) to less than 300 t. In contrast, this trend was reversed for sailfishes, for which the bycatch increased from 25 t to 45 t. The difficulty of defining indices that express the conservation status in marine fishes and that gauge key ecosystem parameters and the need to promote an ecosystem approach for large-pelagic-resource management which takes into account biologic and socioeconomic criteria are briefly discussed

Le thon : enjeux et stratégies pour l'océan Indien

L'étude de la faune associée aux thonidés s'appuie sur l'embarquement d'observateurs scientifiques à bord des thoniers senneurs français et espagnols. C'est la distance entre une espèce pélagique et le banc de thons (inférieure à 650 m) qui définit si l'espèce est associée ou non au banc de thon. Les associations d'une espèce donnée avec les thonidés sont fortement liées aux types de bancs. L'analyse porte sur 432 calées. Les espèces associées aux bancs libres et aux animaux sont les plus gros albacores et patudos (de poids supérieur à 30 kg), les diodons et les exocets et les voiliers ; les espèces essentiellement associées aux objets naturels flottants sont les petits albacores et patudos (de poids inférieur à 10 kg) les marlins, les petits thonidés, les requins soyeux, les balistes, les coryphènes, les élagatis. Les objets flottants artificiels retiennent d'importantes quantités de kyphosidés et de wahoos, de requins océaniques et d'espadons. Les bancs libres se rencontrent dans le canal de Mozambique et à l'est des Seychelles. L'association avec les animaux est prépondérante au sud des Seychelles, les épaves naturelles dans la zone à l'ouest des Seychelles, les épaves artificielles dans la zone nord équatoriale et à l'est des Seychelles. (Résumé d'auteur

Statistics of the purse seine Spanish fleet in the Indian Ocean (1990-2011)

This document presents summary statistics of the purse seiner Spanish fleet fishing in the Indian Ocean from 1990 to 2011. Data include catch and effort statistics as well as some fishery index by species and fishing mode. Information about the sampling scheme and the coverage of sampling, together with maps and diagrams representing the fishing pattern of this fleet by time and area strata is also included

Low cost gaze estimation: knowledge-based solutions

Eye tracking technology in low resolution scenarios is not a completely solved issue to date. The possibility of using eye tracking in a mobile gadget is a challenging objective that would permit to spread this technology to non-explored fields. In this paper, a knowledge based approach is presented to solve gaze estimation in low resolution settings. The understanding of the high resolution paradigm permits to propose alternative models to solve gaze estimation. In this manner, three models are presented: a geometrical model, an interpolation model and a compound model, as solutions for gaze estimation for remote low resolution systems. Since this work considers head position essential to improve gaze accuracy, a method for head pose estimation is also proposed. The methods are validated in an optimal framework, I2Head database, which combines head and gaze data. The experimental validation of the models demonstrates their sensitivity to image processing inaccuracies, critical in the case of the geometrical model. Static and extreme movement scenarios are analyzed showing the higher robustness of compound and geometrical models in the presence of user's displacement. Accuracy values of about 3° have been obtained, increasing to values close to 5° in extreme displacement settings, results fully comparable with the state-of-the-art

Statistics of the purse seine spanish fleet in the Indian Ocean (1984- 2009)

This document presents summary statistics of the purse seiner Spanish fleet fishing in the Indian Ocean from 1990 to 2009. Data include catch and effort statistics as well as some fishery index by species and fishing mode. Information about the sampling scheme and the coverage of sampling, together with maps and diagrams representing the fishing patter n of this fleet by time and area strata is also included

Statistics of the main purse seine fleets fishing in the Indian Ocean (1981-2008).

This document presents a summary of the statistics of French, Spanish, Italian, Seychelles and EU related NEI purse seine fleets fishing in the Indian Ocean since 1981: effort, catch by species and fishing type (log and free swimming schools), catch per unit of effort, sampling and mean weights for the main species. Since 2002, data from the European fleet (France and Spain) are collected within the framework of the EU “Data Collection Regulation” (DCR, Reg. 1543/2000 and 1639/2001), followed in 2008 by the “Community framework for the collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy” (DCF, Reg 199/2008 and 665/2008). Data from other fleets are collected by SFA (Seychelles Fishing Authority). Data processing (species composition and size distribution) is done collectively for the whole fishery