By-catch and Discards in European Purse Seine Tuna Fishery: 2003-2007 Insights
This study analyzes the by-catch and discards associated with the European purse seine tuna fishery in the Indian Ocean from 2003 to 2007. It discusses the importance of these issues, presenting terminology, objectives, and methodologies for estimating by-catch. The research focuses on species composition, length and sex structure of discarded species, and the utilization of by-catch, underlining the main characteristics observed and data collection regulations. Insights from data cover a wide range of species including major and small tunas, billfishes, and associated by-catch species.
By-catch and Discards in European Purse Seine Tuna Fishery: 2003-2007 Insights
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Presentation Transcript
BY-CATCH AND DISCARDS OF THE EUROPEAN PURSE SEINE TUNA FISHERY IN THE INDIAN OCEAN. CHARACTERISTICS AND ESTIMATION FOR THE 2003-2007 PERIOD
AMANDE Justin Monin(1), ARIZ Javier (2), CHASSOT Emmanuel(3), CHAVANCE Pierre(3), DELGADO de Molina Alicia (2), GAERTNER Daniel(3), MUROA Hilario (4), PIANET Renaud (5), RUIZ Jon (4) 1) Centre de Recherches Océanologiques (CRO), Abidjan, Ivory Coast 2) Instituto Espanol de Oceanografia (IEO), Tenerife-Canary Island, Spain 3) Institut de Recherches pour le Développement (IRD), Centre de Recherche Halieutique Méditerranéenne et Tropicale (CRH), Sète, France 4) AZTI Tecnalia, Herrera Kaia, Portualde z :g, 20110, Pasaia (Gipuzkoa), Spain 5) Institut de Recherche pour le Développement (IRD) at Seychelles Fishing Authority (SFA), Victoria, Seychelles
Introduction • Importance of bycatch and discards issues • Terminology • Tuna discards (major tunas and small tunas) • Bycatch (associated species discarded or valorized) • Objectives : • Estimation • Main characteritsics • Species composition • Length and sex structure • Utilisation
Data and Methods (1 of 4) • Data Collection Regulation (Reg. 1543/2000 and 1639/2001) • France (IRD), Spain (AZTI, IEO) • 10 % coverage targeted • Methods (Observer programs) • Route and environment • Fishing operation • Tuna length structure tuna • Associated species biological and length characteristics • Floating device
Data and Methods (2 of 2) • Spain started in 2003 and France in 2005 • Preparation of data. FAD, FSC, Msm (5 miles) • Extrapolation • Stratification • Quarter • Fishing mode (FAD, FSC, MSM) • Zone ET (“Echantillonnage thonier”) • Estimation for large groups of species (discarded tunas, billfishes, fishes, sharks, rays) • Confidence interval by re sampling method
Results • Data coverage
Results • Data coverage