Acoustic characterisation of pelagic fish aggregations around moored fish aggregating devices in Martinique (Lesser Antilles)

Sea cruises were conducted for 57 days over 16 months to characterise pelagic fish aggregations around 2 moored fish aggregating devices (FADs) in Martinique (Lesser Antilles). Echosounder surveys run in a star pattern were used in conjunction with obliquely beamed sonar observations. An echo-integration-by-shoal algorithm was implemented to isolate pelagic fish shoals from sound scattering layers and to compute mean morphometric, positional and density parameters. Tree regressions were used to select and classify pelagic fish Target Strengths (TS), with reference to their spatial and temporal characteristics. The main type of pelagic fish aggregation was a large subsurface aggregation. It was observed during all daytime periods within a radius of 400 m of the FAD. A smaller type of aggregation was observed closer to the surface and to the FAD in 65% of daytime periods. Large scattered fish were observed in 16% of daytime periods. At night, a medium-sized aggregation was detected in the sub-surface in 75% of night-time periods. The sizes of the fish inside the aggregations (determined from TS values) were lower in the small near-surface aggregation than in the large sub-surface aggregation. Mean packing densities of sub-surface medium fish and nearsurface small fish aggregations (determined from TS and shoal acoustic density) were respectively 0.2 fish per m 3 and 1.3 fish per m 3 . The acoustic methodology and results are discussed with reference to the characteristics and performance of the echosounder and to the spatial structure of pelagic fish aggregations around moored FADs in Martinique.

[1]  M. Barangé,et al.  Determination of composition and vertical structure of fish communities using in situ measurements of acoustic target strength , 1994 .

[2]  Noël Diner,et al.  MOVIES-B: an acoustic detection description software. Application to shoal species' classification , 1993 .

[3]  E. Cillaurren.  La pêche à la traîne autour des dispositifs de concentration de poissons mouillés à Vanuatu : un exemple dans le Pacifique sud-ouest , 1987 .

[4]  J. Graves,et al.  HABITAT PREFERENCES OF ISTIOPHORID BILLFISHES IN THE WESTERN NORTH ATLANTIC: APPLICABILITY OF ARCHIVAL TAG DATA TO HABITAT- BASED STOCK ASSESSMENT METHODOLOGIES , 2003 .

[5]  W. C. Leggett,et al.  Hydroacoustic Signal Classification of Fish Schools by Species , 1988 .

[6]  T. Dempster.  Biology of fish associated with moored fish aggregation devices (FADs): implications for the development of a FAD fishery in New South Wales, Australia , 2004 .

[7]  L. Dagorn,et al.  An acoustic approach to study tuna aggregated around fish aggregating devices in French Polynesia: methods and validation , 1999 .

[8]  S. Georgakarakos,et al.  Artificial neural networks as a tool for species identification of fish schools , 1996 .

[9]  C. Scalabrin,et al.  Automatic shoal recognition and classification based on MOVIES-B software , 1994, Proceedings of OCEANS'94.

[10]  P. Cayré,et al.  Behaviour of yellowfin ( Thunnus albacares ) and skipjack tuna ( Katsuwonus pelamis ) around FADs as determined by sonic tagging , 1991 .

[11]  Erwan Josse,et al.  In situ acoustic target strength measurements of tuna associated with a fish aggregating device , 2000 .

[12]  T. Pitcher,et al.  Predator-avoidance behaviours of sand-eel schools: why schools seldom split , 1983 .

[13]  S. Kakuma.  Current, catch and weight composition of yellowfin tuna with FADs off Okinawa island, Japan , 2000 .

[14]  K. Foote.  Fish target strengths for use in echo integrator surveys , 1987 .

[15]  J. Magnuson,et al.  Finescale biological patchiness of 70 kHz acoustic scattering at the edge of the Gulf Stream—EchoFront 85 , 1990 .

[16]  E. John Simmonds,et al.  Fisheries Acoustics: Theory and Practice , 2005 .

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

[18]  A. Bertrand,et al.  Tuna target-strength related to fish length and swimbladder volume , 2000 .

[19]  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 .

[20]  Kim N. Holland,et al.  Dynamics of bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna in Hawaii’s pelagic fisheries: analysis of tagging data with a bulk transfer model incorporating size-specific attrition , 2003 .

[21]  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 .

[22]  David G. Reid,et al.  Image Analysis Techniques for the Study of Fish School Structure from Acoustic Survey Data , 1993 .

[23]  F. Andaloro,et al.  An overview of the FADs fishery in the Mediterranean Sea , 2000 .

[24]  P. Cayré,et al.  Marquage acoustique et comportement de thons tropicaux (albacore : THUNNUS ALBACARES, et listao : KATSUWONUS PELAMIS) au voisinage d'un dispositif concentrateur de poissons , 1986 .

[25]  A. Bertrand,et al.  In situ acoustic target-strength measurement of bigeye ( Thunnus obesus ) and yellowfin tuna ( Thunnus albacares ) by coupling split-beam echosounder observations and sonic tracking , 1999 .

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

[27]  T. Mulligan,et al.  Bias Correction of Rockfish School Cross Section Widths from Digitized Echo Sounder Data , 1993 .

[28]  A. Belousov,et al.  Multiple sound scattering by densely packed shoals of marine animals , 1996 .

[29]  Tim Dempster,et al.  Temporal variability of pelagic fish assemblages around fish aggregation devices : biological and physical influences , 2005 .

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

[31]  Alain Hillion,et al.  Narrowband acoustic identification of monospecific fish shoals , 1996 .

[32]  Leo Breiman,et al.  Classification and Regression Trees , 1984 .

[33]  W. M. Matsumoto,et al.  Anchored fish aggregation devices in Hawaiian waters , 1979 .

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

[35]  E. Cillaurren.  Daily fluctuations in the presence of Thunnus albacares and Katsuwonus pelamis around fish aggregating devices anchored in Vanuatu, Oceania , 1995 .

[36]  Richard W. Brill,et al.  Vertical movements of bigeye tuna (Thunnus obesus) associated with islands, buoys, and seamounts near the main Hawaiian Islands from archival tagging data , 2003 .

[37]  Manuel Barange,et al.  Acoustic identification, classification and structure of biological patchiness on the edge of the Agulhas Bank and its relation to frontal features , 1994 .

[38]  Claireaux,et al.  Telemetry ' applied to behaviour analysis of yellowfin tuna ( Thunnus albacares , Bonnaterre , 1788 ) movements in a network of fish aggregating devices , 2002 .

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

[40]  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.

[41]  Pierre Petitgas,et al.  Standard protocols for the analysis of school based data from echo sounder surveys , 2000 .

[42]  Kenneth G. Foote,et al.  Optimizing copper spheres for precision calibration of hydroacoustic equipment , 1982 .

[43]  Sophie Bertrand,et al.  Waves of agitation inside anchovy schools observed with multibeam sonar: a way to transmit information in response to predation , 2006 .

[44]  J. Magnuson,et al.  Characterization of Patches Along Transects Using High-Resolution 70-kHz Integrated Acoustic Data , 1989 .

[45]  K. Yokawa,et al.  VERTICAL DISTRIBUTION OF ATLANTIC BLUE MARLIN OBTAINED FROM POP-UP ARCHIVAL TAGS IN THE TROPICAL ATLANTIC OCEAN , 2004 .

[46]  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 .

[47]  Robert Kieser,et al.  Classification of Fish Assemblages based on Echo Integration Surveys , 1991 .

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

[49]  T. Pitcher,et al.  Fish school density and volume , 1979 .

[50]  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 .

[51]  Noël Diner,et al.  Correction on school geometry and density: approach based on acoustic image simulation , 2001 .

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

[53]  M. Eero.  Consequences of management of pikeperch (Stizostedion lucioperca L.) stock in Pärnu Bay (Baltic Sea) under two different economic regimes, 1960–1999 , 2004 .

[54]  A. Ōkubo,et al.  An analysis of the kinematics of swarming ofAnarete pritchardi kim (Diptera: Cecidomyiidae) , 1974, Researches on Population Ecology.