SCRS/2008/171
Collect. Vol. Sci. Pap. ICCAT, 64(6): 2124-2127 (2009)
PROGRESS OF THE ICCAT ENHANCED RESEARCH PROGRAM FOR BILLFISH IN THE WESTERN ATLANTIC OCEAN DURING 2008 Eric D. Prince 1, 2 and John P. Hoolihan1,3
SUMMARY Research activities of the ICCAT Enhanced Research Program for Billfish in the Western Atlantic Ocean during 2008 are summarized by location and research objective. At-sea sampling with observers on Venezuelan industrial longline vessels accomplished 4 trips from August 2007 through July 2008, and more trips are targeted before the end of the year. Most of the vessels are based out of Cumana and Lecheria/Pto. La Cruz targeting tuna and swordfish, or both at the same time. Biological sampling of istiophorids in Venezuela for reproductive and age determinations studies were continued during 2008. This was also accomplished in Bermuda and the US, where gonads and hard parts for age determination from several large blue marlin were obtained, including two specimens well over 1,000 pounds. Shore-based sampling of billfish landings for size frequency data, as well as tournament sampling was accomplished in Grenada, Bermuda, and Barbados. Program participants in Venezuela, Grenada, and Barbados continued to assist in obtaining information on tag-recaptured billfish, as well as numerous sharks, in the western Atlantic Ocean during the last quarter of 2007 and first three quarters of 2008. A total of 59 tag recovered billfish, 22 blue marlin, 23 white marlin, 12 sailfish and 2 sharks were recaptured. RÉSUMÉ Le présent document résume les activités de recherche du Programme ICCAT de recherche intensive sur les istiophoridés mené dans l’océan Atlantique Ouest en 2008, par emplacement et objectif de recherche. Des observateurs embarqués à bord de palangriers industriels vénézuéliens ont réalisé un échantillonnage en mer à l’occasion de quatre sorties d’août 2007 à juillet 2008, et davantage de sorties sont projetées avant la fin de l’année. La plupart des navires ont leur port d’attache à Cumaná et Lecheria/Port de La Cruz et ciblent les thonidés et l’espadon, ou les deux espèces à la fois. L’échantillonnage biologique des istiophoridés s’est poursuivi en 2008 au Venezuela dans le cadre d’études sur la reproduction et la détermination de l’âge. Ceci a également été réalisé aux Bermudes et aux Etats-Unis où des gonades et des pièces dures ont été obtenues de plusieurs grands spécimens de makaire bleu aux fins de la détermination de l’âge, y compris deux spécimens pesant bien plus de 1.000 livres. Un échantillonnage des débarquements d’istiophoridés réalisé à terre pour obtenir des données de fréquence de taille, ainsi qu’un échantillonnage a été réalisé à la Grenade, aux Bermudes et à la Barbade à l’occasion de championnats. Les participants au programme au Venezuela, à la Grenade et à la Barbade ont continué à obtenir des informations sur les istiophoridés porteurs de marques qui ont été récupérés, ainsi que sur de nombreux requins, dans l’océan Atlantique Ouest au cours du dernier trimestre de 2007 et des trois premiers de 2008. Au total, 59 marques ont été récupérées sur des istiophoridés, 22 sur des makaires bleus, 23 sur des makaires blancs, 12 sur des voiliers et 2 sur des requins. RESUMEN Se resumen las actividades de investigación del Programa ICCAT de investigación intensiva sobre marlines en el Atlántico occidental durante 2008 por localización y objetivo de investigación. El muestreo en el mar con observadores a bordo de palangreros industriales 1 U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, FL 33149-1099. E-mail:
[email protected] 2 Sustainable Fisheries Division Contribution SFD-2008-022. 3 University of Miami, Rosenstiel School of Marine & Atmospheric Sciences, 4600 Rickenbacker Causeway, Miami, FL 33149.
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venezolanos se realizó en 4 mareas desde agostó de 2007 hasta julio de 2008 y se han programado más mareas antes de finales del año. La mayoría de los barcos tienen su base en Cumaná y Lecheria/Puerto La Cruz y se dirigen a los túnidos y al pez espada o a ambos a la vez. El muestreo biológico de istiofóridos en Venezuela para estudios reproductivos y de determinación de la edad ha continuado durante 2008. Este muestreo se ha realizado también en Bermudas y Estados Unidos, donde se han obtenido las gónadas y partes duras para la determinación de la edad procedentes de varias agujas azules grandes, incluyendo dos ejemplares de bastante más 1.000 libras. El muestreo en tierra de los desembarques de marlines para datos de frecuencia de tallas, así como el muestreo de torneos se realizó en Granada, Bermudas y Barbados. Los participantes del programa en Venezuela, Granada y Barbados continuaron ayudando en la obtención de información sobre marlines marcados y recapturados, así como sobre varios tiburones, en el Atlántico occidental durante el último trimestre de 2007 y los tres primeros trimestres de 2008. Se recapturó un total de 59 marlines marcados, 22 agujas azules, 23 agujas blancas, 12 peces vela y 2 tiburones.
KEY WORDS Billfish, Western Atlantic Ocean, Research coordination
1. Introduction Dr. David Die, with the University of Miami Rosenstiel School of Marine and Atmospheric Science and chairman of the billfish working group, made a trip to West Africa during the second quarter to met with scientists from Dakar, Senegal to collect cpue data on the artisanal fisheries for sailfish. The following summarizes research progress according to location and/or type of research activity. Research activities during 2008 began immediately after the SCRS meeting in October, 2007. The objectives in the initial program plan in 1986 (Appendix to Annex 12 of Report of Biennial Period, 1986-87 part 1) have not changed, and include: (1) Provide more detailed catch and effort statistics; (2) Initiate and expand the ICCAT billfish tagging program; and (3) Assist in collecting data for age and growth studies. The two locations for intensive scientific study given in the original plan remain the Caribbean Sea and the west coast of Africa. The overall program coordinator during 2008 was Dr. David Die (U.S.A.); Dr. Eric D. Prince (U.S.A.) was coordinator for the western Atlantic Ocean, and Mr. Paul Bannerman (Ghana) coordinated activities for the eastern Atlantic Ocean. Starting in October, 1998, there were changes in the financial structure of the Program and these changes are detailed in the financial report for the 1998 SCRS. In terms of affecting research activities, scientists collaborating in the ICCAT Enhanced Research Program for Billfish (IERPB) were asked to make requests for release of funds directly from the ICCAT Secretariat and these requests were then verified by area coordinators. Reductions in contributions to IERPB were again a problem in 2006, as they had been the previous year. Due to a reduction in available funding, the research activities for 2008 operated at about 50% compared to previous fully funded years. The lack of funding for the program over the last two years is now becoming a factor relative to the amount of work that can be carried out. The following coordination activities were realized by this program during 2008 the western Atlantic Ocean. 1.1 Objective 1, Landing statistics The following summarizes research progress according to location and/or type of research activity: Barbados: The shore-base sampling in Barbados was not conducted due to low fishing effort but data from several recreational billfish tournament were obtained in 2008. Summaries of catch and effort data from these recreational billfish tournaments are normally submitted to the western Atlantic Coordinator at the end of the year. Dr. Hazel Oxenford, billfish coordinator for Barbados, has initiated tagging activities from several of the recreational billfish tournaments during the last few years.
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Bermuda: Staff of the Bermuda Division of Fisheries continued to collect catch and effort statistics from billfish tournaments at this location. Bermuda continued to collaborate in collecting biological material from its billfish tournaments during 2008.
Brazil: Dr. Alberto Amorim of Institute de Pesca continued his billfish conventional tagging activities in 2008. With funding from the National Marine Fisheries Service (USA) and the Special Secretariat of Fisheries and Aquaculture (Secretaria Especial de Aqüicultura e Pesca- SEAP/ PR; Brazil), Dr. Fabio Hazin and Dr. Paulos Travassos of the Federal Rural University in Pernambuco continued a joint billfish research program in 2008 with Dr. David Die (UM/ RSMAS), Dr. Mahmood Shivji and Dr. David Kerstetter (NSU), and Dr. John Graves of the Virginia Institute of Marine Science. Work in 2007 and 2008 under this program focused on billfish interactions with pelagic fishing gears, including circle and J-style hook comparisons in the equatorial pelagic longline fishery; tagging of blue marlin, white marlin, and sailfish with popup satellite tags; age and growth and reproductive biology of blue and white marlins. A graduate student from Brazil visited the Southeast Fisheries Science Center for 3 months during 2007 and worked with Dr. Kerstetter and SEFSC staff in order to analyze data from popup satellite archival tags; while a PhD student spent a similar time in UM/ RSMAS, to adjust the methodology used in the age and growth study in 2008. Biological samples for genetic analyses from Brazil were also obtained in 2008. Additional details on this program, including future research plans, can be found in 2008 SCRS working documents.
Grenada: The Ministry of Industrial Development and Fisheries (MIDF) continued limited shore-based sampling activities of the artisanal fisheries during the 2008 season. The MIDF also notified the western Atlantic Coordinator that a transportation problem exists that currently is preventing shore based sampling at some of the more remote landings sites. Data from the 2008 Spice Island Billfish Tournament were also collected, including CPUE, size and sex information of billfish landings.
Jamaica: A new ICCAT billfish coordinator for this location has not been determined. Most of the billfishing activity in Jamaica takes place in the fall to coincide with the billfish tournament schedule. We normally gain access to these data at the end of the fishing season.
St. Maarten, N.A.: The billfish tournament normally held on St Martin was not sampled during 2005 due to constraints imposed by the limited budget. This also prevented our normal sampling of size frequency data from the Nichirei Carib Corporation at St. Maarten (Dutch side).
St. Vincent: Members of CARICOM continue their efforts in tagging small pelagic species throughout the Caribbean. Research cruises aboard the St. Vincent Department of Fisheries longline vessel were not made during 2008. This activity will be re-evaluated to determine if it is appropriate to continue this research next year. Venezuela: At-sea sampling activities of INIA continued at the port of Cumana, where the fleet of industrialized longline vessels target yellowfin tuna and swordfish, but also catch billfish. In addition, the fleet of smaller artisanal vessels often target billfish. There were a total of 4 at-sea observer trips accomplished since the last SCRS meeting (Aug. 2007 to Jun. 2008). Most trips were on industrialized small to mid size longline vessels out of the port of Cumana. Shore-based sampling of size frequency data in Venezuela continued at about the same rate as 2007, with harbor samplings in Playa Verde and Cumaná, but was reduced at Margarita Island since most of the catch in northeastern Venezuela is being sold at sea to vessels which carry fish to other Caribbean Islands. Recoding of information on catch and effort from daily recreational trips as well as sport fishing tournaments continued during 2007-2008. The number of tournaments organized annually continues at a decreased level in the central Venezuelan coast. Since all animals are released by law in the tournaments made in the central Venezuelan coast, no sampling was made from the recreational tournaments held in Playa Grande Marina in 2007-2008. A major effort to obtain reports of tag recaptured billfish continued during 2007-2008. These results are including in the tagging section (below). U.S. Virgin Islands: Several billfish tournaments held during 2008 (normally at least 3 tournaments are held each year) and these results are reported to the Southeast Fisheries Science Center. 2126
1.2 Objective 2, Billfish Tagging Program About 59 conventional tag recaptured billfish have been reported to the western Atlantic Coordinator through September, 2008. Most of these were from Venezuela (59 tag returns between August 2007 and April 2008). These recaptures represent both NMFS and The Billfish Foundation tags and continues to indicate increased tag recapture reporting rates in the southeast Caribbean Sea as a result of the ICCAT Enhanced Research Program for Billfish. In addition, most of the recaptured fish were blue and white marlin. A number of Atlantic-wide tagging programs have encaged in tagging billfish using popup satellite tag (PSAT) technology. Efforts in the western Atlantic have focused on sailfish of south Florida, as well as off Senegal, West Africa. Swordfish have also been tagged with PSATs off south Florida. 1.3 Objective 3, Age and growth Even though the Program had a reduction in budget allocations for 2008 activities, the current sampling year resulted in a general increase in age and growth and reproductive studies. Venezuela continued to accelerate its biological sampling for age and growth and reproductive studies in 2008. Several sets of hard parts were obtained from very large blue marlin over 1,000 lbs during the 2008 sampling season. Ms Kate Drew, working under the direction of Dr. David Die at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, is completing her analysis of the age and growth of white marlin. Primary sources of hard parts for this study have been obtained from Venezuela, Brazil, and the US.
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