Fish behaviour from fishers' knowledge: the case study of tropical tuna around drifting fish aggregating devices (DFADs)

Purse-seining for tropical tuna is one of the most technologically advanced fisheries in the world. The pur- pose of this study was to apply local ecological knowledge (LEK) to assist in the planning of future in situ studies of fish behaviour around drifting fish aggregating devices (DFADs) by prioritizing research topics, thereby reducing the number of potential hypotheses to explore. Interviews of fishing masters of the purse-seine fleets working in the west- ern Indian Ocean provided an alternate, independent, and previously unexplored source of behavioural information, spe- cifically on the attraction, retention, and departure behaviours of tuna schools in relation to DFADs. Most fishing masters agreed that the maximum attraction distance of a DFAD is approximately 10 km and generally agreed to the following statements. Tuna form distinct schools under FADs, commonly segregated by species and size. The main rea- sons for the departure of tuna aggregations from FADs are changes in currents or FAD movements and location in re- lation to physical or oceanographic features. The number of actively monitored DFADs at sea in the western Indian Ocean was estimated at approximately 2100. Incorporating fishers into the planning and design stages of future re- search projects will facilitate collaborative and integrated approaches. Resume : La peche thoniere tropicale a la senne coulissante est l'une des peches commerciales les plus avancees techno- logiquement au monde. Le but de notre travail est d'utiliser les connaissances ecologiques locales (« LEK ») pour aider a planifier les etudes futures in situ sur le comportement des poissons autour des dispositifs derivants de concentration des poissons (« DFADs ») en etablissant une priorite dans les sujets de recherche, reduisant ainsi le nombre potentiel d'hypotheses a explorer. Des entrevues avec les capitaines de peche des flottes qui utilisent la senne coulissante dans l'ouest de l'Ocean Indien fournit une source de remplacement independante et encore inexploree de renseignements com- portementaux, en particulier sur les comportements d'attirance, de retention et de depart des bancs de thons en relation avec ces DFAD. La plupart des capitaines de peche sont d'accord que la distance maximale d'attraction d'un DFAD est d'environ 10 km et ils conviennent generalement des propositions suivantes : les thons forment des bancs distincts sous les FAD, souvent separes en fonction de l'espece et de la taille; les raisons principales de l'abandon des FAD par les ras- semblements de thons sont des changements dans les courants ou alors les deplacements et les positionnements des FAD par rapport aux caracteristiques physiques ou oceaniques. Le nombre de DFAD qui sont suivis activement en mer dans l'ouest de l'Ocean Indien est estime a environ 2100 objets en derive. L'implication des pecheurs dans les phases de la planification et de la conception des futurs projets de recherche favorisera la collaboration et l'integration. (Traduit par la Redaction) Moreno et al.

[1]  Martha Johnson,et al.  Lore : capturing traditional environmental knowledge , 1992 .

[2]  M. Taquet,et al.  Mechanisms and effects of the aggregation of tuna by Fish Aggregating Devices (FADs) , 2000 .

[3]  Mathieu Doray,et al.  Acoustic characterisation of pelagic fish aggregations around moored fish aggregating devices in Martinique (Lesser Antilles) , 2006 .

[4]  L. Dagorn,et al.  Using local ecological knowledge (LEK) to provide insight on the tuna purse seine fleets of the Indian Ocean useful for management , 2007 .

[5]  Pierre Fréon,et al.  Dynamics of pelagic fish distribution and behaviour : effects on fisheries and stock assessment , 1999 .

[6]  J. Castro,et al.  A general theory on fish aggregation to floating objects: An alternative to the meeting point hypothesis , 2002, Reviews in Fish Biology and Fisheries.

[7]  J. Hampton,et al.  FISHING FOR TUNAS ASSOCIATED WITH FLOATING OBJECTS: A REVIEW OF THE WESTERN PACIFIC FISHERY , 1993 .

[8]  Tim Dempster,et al.  Fish aggregation device (FAD) research: gaps in current knowledge and future directions for ecological studies , 2004, Reviews in Fish Biology and Fisheries.

[9]  Simon Benhamou,et al.  FAD: Fish Aggregating Device or Fish Attracting Device? A new analysis of yellowfin tuna movements around floating objects , 2004, Animal Behaviour.

[10]  Andrew Seidl,et al.  Participatory research methods in environmental science: local and scientific knowledge of a limnological phenomenon in the Pantanal wetland of Brazil , 2000 .

[11]  Pierre Fréon,et al.  Review of fish associative behaviour: Toward a generalisation of the meeting point hypothesis , 2000, Reviews in Fish Biology and Fisheries.

[12]  K. Holland,et al.  HORIZONTAL AND VERTICAL MOVEMENTS OF YELLOWFIN AND BIGEYE TUNA ASSOCIATED WITH FISH AGGREGATING DEVICES , 1990 .

[13]  Alain Fonteneau,et al.  A worldwide review of purse seine fisheries on FADs , 2000 .

[14]  Erwan Josse,et al.  Typology and behaviour of tuna aggregations around fish aggregating devices from acoustic surveys in French Polynesia , 2000 .

[15]  A. Klimley,et al.  School fidelity and homing synchronicity of yellowfin tuna, Thunnus albacares , 1999 .

[16]  David Itano,et al.  Behavior of yellowfin (Thunnus albacares) and bigeye (T. obesus) tuna in a network of fish aggregating devices (FADs) , 2007 .

[17]  M. Mangel,et al.  AGGREGATION AND FISHERY DYNAMICS : A THEORETICAL STUDY OF SCHOOLING AND THE PURSE SEINE TUNA FISHERIES l , 2009 .

[18]  John Wagner,et al.  Who Knows? On the Importance of Identifying “Experts” When Researching Local Ecological Knowledge , 2003 .

[19]  Secretariat Iotc.  Report of the Fifth Session of the IOTC Working Party on Tropical Tunas , 2003 .

[20]  L. Dagorn,et al.  Individual differences in horizontal movements of yellowfin tuna (Thunnus albacares) in nearshore areas in French Polynesia, determined using ultrasonic telemetry , 2000 .

[21]  J. Hanson,et al.  Local ecological knowledge and marine fisheries research: the case of white hake (Urophycis tenuis) predation on juvenile American lobster (Homarus americanus) , 2004 .

[22]  M. Doray.  L'agrégation de thons de sub-surface au sein du système [DCP ancré - macronecton - environnement - pêche] en Martinique : étude hiérarchique par méthodes acoustiques, optiques et halieutiques , 2006 .

[23]  J. Valbo‐Jørgensen,et al.  Using Local Knowledge as a Research Tool in the Study of River Fish Biology: Experiences from the Mekong , 2000 .

[24]  David Itano,et al.  Characterizing fish communities associated with drifting fish aggregating devices (FADs) in the Western Indian Ocean using underwater visual surveys , 2007 .

[25]  Daniel W. Fuller,et al.  Behavior of bigeye (Thunnus obesus) and skipjack (Katsuwonus pelamis) tunas within aggregations associated with floating objects in the equatorial eastern Pacific , 2005 .

[26]  Marc Taquet,et al.  Le comportement agrégatif des dorades coryphènes (Coryphaena hippurus) autour des objets flottants , 2004 .

[27]  D. Schneider,et al.  11. An Interdisciplinary Method for Collecting and Integrating Fishers' Ecological Knowledge into Resource Management , 1999 .

[28]  E. Baran,et al.  Fishermen's knowledge as background information in tropical fish ecology: a quantitative comparison with fish sampling results , 1997, Environmental Biology of Fishes.

[29]  I. Ohta,et al.  Periodic behavior and residence time of yellowfin and bigeye tuna associated with fish aggregating devices around Okinawa Islands, as identified with automated listening stations , 2005 .

[30]  S. Mackinson,et al.  Integrating Local and Scientific Knowledge: An Example in Fisheries Science , 2001, Environmental management.

[31]  D. Doulman.  Tuna issues and perspectives in the Pacific Islands region , 1987 .

[32]  M. Freeman,et al.  Ignore fishers’ knowledge and miss the boat , 2000 .

[33]  Patrice Brehmer,et al.  Echotrace classification and spatial distribution of pelagic fish aggregations around drifting fish aggregating devices (DFAD) , 2007 .

[34]  L. Dagorn,et al.  Simultaneous observations of tuna movements and their prey by sonic tracking and acoustic surveys , 1998, Hydrobiologia.

[35]  K. Holland.  Biological aspects of the association of tunas with FADs , 1996 .

[36]  R. Hilborn,et al.  Tuna Purse-Seine Fishing with Fish-Aggregating Devices (FAD): Models of Tuna FAD Interactions , 1989 .

[37]  A. Begossi,et al.  Local knowledge on a cosmopolitan fish ethnoecology of Pomatomus saltatrix (Pomatomidae) in Brazil and Australia , 2005 .

[38]  Barbara A. Block,et al.  Horizontal movements and depth distribution of large adult yellowfin tuna (Thunnus albacares) near the Hawaiian Islands, recorded using ultrasonic telemetry: implications for the physiological ecology of pelagic fishes , 1999 .

[39]  P. Nelson.  Marine fish assemblages associated with fish aggregating devices (FADs): effects of fish removal, FAD size, fouling communities, and prior recruits , 2003 .

[40]  E. Hviding,et al.  Traditional knowledge possessed by the fishers of Marovo Lagoon, Solomon Islands, concerning fish aggregating behaviour. , 2000 .

[41]  E. Josse,et al.  Movement patterns of large bigeye tuna (Thunnus obesus) in the open ocean, determined using ultrasonic telemetry , 2000 .

[42]  M. Hall.  An ecological view of the tuna--dolphin problem: impacts and trade-offs , 1998, Reviews in Fish Biology and Fisheries.

[43]  J. Hallier,et al.  Review of tuna fisheries on floating objects in the Indian Ocean , 1992 .