SCRS/2003/025 Col. Vol. Sci. Pap. ICCAT, 56(1): 226-229(2004)

PROGRESS OF THE ICCAT ENHANCED RESEARCH PROGRAM FOR BILLFISH IN THE WESTERN ATLANTIC OCEAN DURING 2003

Eric D. Prince1

SUMMARY

Research activities of the ICCAT Enhanced Research Program for Billfish in the Western Atlantic Ocean during 2003 are summarized by location and research objective. At-sea sampling with observers on Venezuelan industrial longline vessels accomplished 18 trips from January through August 2003, and more trips are targeted before the end of the year. Of the trips accomplished to date, 5 observer trips were on Korean type vessels fishing under the Venezuelan flag. In addition, a total of 6 observer trips were made on industrialized longline vessels during the last quarter of 2002. Most of these vessels are based out of Cumana targeting tuna and/or swordfish. Biological sampling of swordfish, Istiophorids, and yellowfin tuna for reproductive and age determination studies was continued during 2003. Shore-based sampling of billfish landings for size frequency data, as well as tournament sampling were accomplished in Venezuela, 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 2003 (75 tag recovered billfish and sharks). Several sets of hard parts for ageing studies were obtained from very large blue marlin caught in Ascension Island, UK.

RÉSUMÉ

Le présent document résume, par emplacement et par objectif de recherche, les activités de recherche menées dans le cadre du Programme de recherche intensive de l’ICCAT sur les Istiophoridés dans l’océan Atlantique ouest. Des échantillonnages en mer ont été réalisés avec des observateurs postés à bord de palangriers industriels vénézuéliens qui ont effectué 18 sorties de janvier à août 2003, et de nouvelles sorties sont prévues d’ici la fin de l’année. Sur les sorties réalisées jusqu’à ce jour, 5 d’entre elles comprenaient des observateurs embarqués sur des bateaux de type coréen battant pavillon vénézuélien. En outre, 6 sorties avec observateurs ont été effectuées par des palangriers industriels au cours du deuxième semestre de 2002. La plupart de ces bateaux sont rattachés à Cumana et ciblent les thonidés et/ou l’espadon. En 2003, l’échantillonnage biologique de l’espadon, des istiophoridés et de l’albacore s’est poursuivi dans le cadre d’études sur la reproduction et la détermination de l’âge. On a réalisé au Venezuela, à la Grenade, aux Bermudes et à la Barbade des échantillonnages à terre des débarquements d’istiophoridés pour obtenir des données de fréquence de taille, ainsi que des échantillonnages pendant les championnats. Les participants aux programmes au Venezuela, à la Grenade et à la Barbade ont continué d’aider à obtenir des informations sur la recapture des istiophoridés porteurs de marques, ainsi que de nombreux requins, dans l’Atlantique ouest au cours de 2003(75 recaptures d’istiophoridés et de requins porteurs de marques). Plusieurs jeux de pièces dures ont été obtenus de très grands makaires bleus capturés au large de l’île Ascension, Royaume-Uni, afin de réaliser des études de détermination de l’âge.

RESUMEN

Se resumen las actividades de investigación del Programa ICCAT de investigación extensiva sobre marlines en el océano Atlántico occidental durante 2003 en función de su localización y del objetivo de la investigación. El muestreo en el mar con observadores a bordo de los

1 U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Center, 75 Virginia Beach Drive, Miami, FL 33149-1099 Sustainable Fisheries Division Contribution SFD-02/03-179 226

palangreros industriales venezolanos cubrió 18 mareas de enero a agosto de 2003, y se planea realizar más antes de finales de año. De las mareas cubiertas hasta la fecha: 5 mareas de los observadores se llevaron a cabo en barcos de tipo coreano que pescan con bandera de Venezuela. Además, un total de 6 mareas de observadores se desarrollaron a bordo de palangreros industriales durante el último trimestre de 2002. La mayoría de los barcos tienen su base en Cumana y dirigen su actividad al pez espada y/o túnidos. Durante 2003 se continuó con el muestreo biológico de pez espada, istiofóridos y rabil para estudios de reproducción y determinación de la edad. Se realizaron muestreos en tierra firme de los desembarques de marlines para recopilar datos de frecuencias de tallas, así como muestreos de torneos en Venezuela, Grenada y Barbados. Los participantes del programa en Venezuela, Grenada, Bermuda y Barbados siguieron ayudando en la obtención de información sobre recuperación de marcas de marlines, así como de numerosos tiburones, en el océano Atlántico occidental durante 2003(se recuperaron 75 marlines y tiburones con marcas). Se obtuvieron varios conjuntos de partes duras para estudios de determinación de la edad de grandes atunes rojos capturados en la Isla Ascensión, Reino Unido.

KEYWORDS

ICCAT Enhanced Research Program for Billfish, At-sea and shore based billfish sampling in Western Atlantic Ocean

1 Introduction

Research activities during 2003 began immediately after the SCRS meeting in October, 2002. 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 2003 was Dr. Joseph E. Powers (U.S.A.); Dr. Eric D. Prince (U.S.A.) was coordinator for the western Atlantic Ocean, and N’ Goran Ya (Cote D’IVOIRE) 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 2003, as they had been the previous year. Due to a reduction in available funding, the research activities for 2003 operated at about 50% compared to previous fully funded years. The lack of funding for the program over the last three 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 2003 the western Atlantic Ocean.

2 Objective 1 -- Landing Statistics

Dr. Freddy Arocha with the University of Oriente in Cumana, Venezuela, made a trip to Miami during the third quarter to submit data from the Venezuelan Billfish Program and meet with western Atlantic Coordinator and the chairman of the billfish working group (Dr. David Die). Also, Dr. Joe Serafy represented the western Atlantic Coordinator during a coordination trip to Grenada. This training trip was requested by the government of Grenada to re-establish IERPB activities in this location. 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 2003. 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 and these continued in 2003. In the third quarter of

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2003, Dr. Oxenford contacted the western Atlantic coordinator and expressed a desire to expand work on billfish and to include and assessment of the longline fishery in Barbados.

Bermuda. Dr. Brain Luckhurst of the Bermuda Division of Fisheries continues to collect catch and effort statistics from billfish tournaments at this location. In addition, Bermuda continued to collaborate on research evaluating the habitat use of billfish using popup satellite tag technology in the area of Bermuda, Exuma Sound, Bahamas, and elsewhere in the Caribbean Sea. The hard parts and gonads from several very large blue marlin landed in Bermuda, including several fish over 500 pounds, were sampled for age and growth and reproductive studies.

Brazil. Dr. Alberto Amorin of Institute de Pesca continues his billfish tagging activities.

Grenada. The Ministry of Industrial Development and Fisheries limited shore-based sampling activities of the artisanal fisheries during the 2003 season. Data from the 2003 Spice Island Billfish Tournament were also collected, including CPUE, size and sex information of billfish landings. Age and growth sampling marlin and sailfish began in this location during 2003.

St. Maarten, N.A. The billfish tournament normally held on St Martin was not sampled during 2003 due to constraints imp osed by the limited budget. This also prevented our normal sampling of size frequency data from the Nichirei Caribb Corporation at St. Maarten (Dutch side).

Trinidad and Tobago. Shore-based sampling was not conducted during 2003. With consideration of budgetary constraints, this work may be re -activated 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 24 at-sea observer trips accomplished since the last SCRS meeting (Sep. 2002 to Aug. 2003). At least eight of these trips were made on the larger Korean type longline vessels, while most were on industrialized longline vessels out of the ports of Cumana, Puerto La Cruz and La Guaira. Shore -based sampling of size frequency data in Venezuela continued at a higher rate than 2002, with harbor samplings in Playa Verde, but was reduced at Margarita Island and Cumaná since most of the catch in eastern Venezuela is being sold at sea to vessels which carry fish to other Caribbean Islands. A total of 4,452 billfish were measured in Playa Verde in 2002 and 3,432 in 2003 (Jan-Aug), of which 70% are sailfish, followed by blue marlin (21%) and white marlin 9%. Recoding of information on catch and effort from daily recreational trips as well as sport fishing tournaments continued during 2003. After major land slides in La Guaira on 2000, the number of tournaments organized annually have decreased 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 2003. A major effort to obtain reports of tag recaptured billfish continued during 2003. These results are including in the tagging section (below).

U.S. Virgin Islands. Data from several billfish tournaments held during 2002 (normally at least 3 tournaments are held each year) and 2003 have been submitted to the Western Atlantic Coordinator as of this date. In addition, some popup satellite archival tagging of blue marlin was conducted at this location in October 2002 and is also tentatively planned for October of 2003.

3 Objective 2 -- Billfish Tagging Program

A total of over 75 conventional tag recaptured billfish (as well as 5 sharks) have been reported to the western Atlantic Coordinator through September, 2003. Most of these were from Venezuela. These recaptures represent both NMFS and The Billfish Foundation tags and continue 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, more than 50% of the recaptured fish were blue marlin. A number of Atlantic-wide tagging programs have encaged in tagging marlin using popup satellite tag technology. Efforts in the western Atlantic have focused on blue marlin in the area of Exuma Sound, Bahamas, northeast US coast, U.S. Virgin Islands, Turks and Caicos Islands, Puerto Rico, Bermuda, and off the Charleston Hump of South Carolina. In addition, white marlin were first tagged near the southeastern tip of the Dominican Republic and later off the US east coast, as well as La Guaira, Venezuela and in the Mexican Caribbean.

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4 Objective 3 -- Age And Growth

Despite reduced budget allocations that again had to be implemented for 2003 activities, the current sampling year resulted in some progress in age and growth and reproductive studies. For example, a pilot study of reproductive biology of white marlin was conducted in Punta Cana, Dominican Republic and off Venezuelan longline vessels fishing in the central Caribbean Sea. In addition, hard parts from several exceptionally large blue marlin (over 1,000 pounds) pounds were obtained from recreational sources fishing off Ascension Island, UK. Numerous other samples of hard parts from blue marlin, white marlin, and sailfish were obtained off south Florida. More formal requests for obtaining hard parts were made to Program cooperators from Venezuela and Grenada.

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