Marine Turtle Newsletter Number 56 January 1992 Editors: Editorial Board: Karen. L. Eckert & Scott A. Eckert Nat B. Frazer National Marine Fisheries Service Nicholas Mrosovsky Southwest Regional Office David W. Owens c/o SWFSC, Post Office Box 271 Peter C H. Pritchard La Jolla, California 92038-0271 USA James 1. Richardson OBSERVATIONS ON FIRST BREEDING BY A LOGGERHEAD TURTLE Regular capture of loggerhead sea turtles (Caretta caretta) living year-around on coral reef feeding areas adjacent to Heron Island (southern Great Barrier Reef, Australia) began in August 1974. The turtles are captured by leaping onto them from a speedboat -- what we call our "turtle rodeo". Effectively all the loggerhead turtles living on Heron Island Reef were tagged using this technique by 1977. Since then, almost all new, untagged turtles have been relatively small; i.e., 70-85 cm curved carapace length (CCL). Loggerheads <70 cm CCL are uncommon anywhere in the Great Barrier Reef. Each year a fresh crop of small loggerheads appears among the local turtles at Heron Island Reef. These new recruits to the feeding area typically remain on the reef over the years that follow and grow to maturity. Let me introduce you to one such recruit, marked with tag number X2757. I first met her as an immature turtle on 19 May 1977 in the sandy lagoon area of Heron Island Reef. She measured 80 cm CCL and weighed 65.5 kg. She has now been captured 36 times on Heron Island Reef (as of April 1991) and she has never been captured feeding on any of the reefs adjacent to Heron Island Reef. In October 1982 she was examined internally by laparoscopy and identified as an immature female with an unexpanded oviduct. Her reproductive system has been examined annually by laparoscopy since 1985, when she was found to have recently completed the elongation and expansion of her oviducts and enlargement of her ovaries. Thus, based on the completion of development of her reproductive system, she first qualified to be called an adult in 1985 at 89.5 cm CCL. In March 1987 and again in March 1989, she was observed to be depositing yolk into large numbers of follicles in her ovaries. However, she did not complete vitellogenesis and therefore did not ovulate any eggs in either of these two years. She was again in vitellogenesis in March 1990 (92.0 cm CCL, 98 kg) and later the same year she made her first successful breeding migration. She was recorded ashore on Lady Musgrave Island, 67 km from her home reef, laying eggs on 16 December 1990 and 18 days later on 3 January 1991, 13 years after she recruited to take up residence within the southern Great Barrier Reef. The number of eggs per clutch were not counted and, because the Lady Musgrave rookery was not monitored during the entire nesting season, the total number of clutches laid during the season was not recorded. During March-April 1991, at the completion of the 1990-91 breeding season, the turtles resident on Heron Island Reef were again captured for sampling. X2757 was again caught in the lagoon area of Heron Island Reef. She still measured 92.0 cm CCL, but weighed only 92 kg. Laparoscopy showed her ovaries to contain numerous corpora albicantia (scars resulting from the ovulation of mature follicles during the breeding season) and large atretic follicles. Because X2757's resident feeding ground at Heron Island Reef is near the center of the nesting concentration for loggerhead turtles in the south Pacific, her breeding migration to a rookery is quite short. In this she resembles other loggerhead turtles living in the area (Limpus et al. 1992). As has been previously demonstrated for other loggerhead turtles that live on these reefs (Limpus 1989), X2757 did not nest at the rookery closest to her home feeding area when she migrated to the Lady Musgrave rookery. Indeed, she by-passed several closer loggerhead rookeries. Heron Island is less than 5 km from where she had lived for the previous 13 years and Wreck Island, 12 km from Heron Island Reef, supports the largest concentration of loggerhead turtle nesting in the south Pacific. Also noteworthy is the fact that she did not commence breeding at 80 cm CCL, the smallest size recorded for breeding female loggerhead turtles in eastern Australia. Instead, she commenced breeding at 92.0 cm CCL, only slightly smaller than average breeding size for loggerhead turtles in eastern Australia (Limpus 1990). X2757 grew slowly during the 13 years preceding her first breeding season, averaging 0.92 cm/yr. This turtle has provided us with the first opportunity to observe the choice of feeding area by a turtle after she breeds for the first time in her life. At the completion of her first breeding season and associated migrations, X2757 returned to the same feeding area as she had occupied during her adolescent years. Limpus, C. J. 1989. Foraging area fidelity following breeding migrations in Caretta caretta, p.97-99. In: Proc. Ninth Annual Workshop on Sea Turtle Biology and Conservation (S. A. Eckert, K. L. Eckert, and T. H. Richardson, Compilers). NOAA Technical Memorandum NMFS-SEFC-232. U. S. Dept. Commerce. Limpus, C. J. 1990. Puberty and first breeding in Caretta caretta, p.81-83. In: Proc. Tenth Annual Workshop on Sea Turtle Biology and Conservation (T. H. Richardson, J. I. Richardson, and M. Donnelly, Compilers). NOAA Technical Memorandum NMFS- SEFC-286. U. S. Dept. Commerce. Limpus, C. J., J. D. Miller, C. J. Parmenter, D. Reimer, N. McLachlan, and R. Webb. 1992. Migration in green (Chelonia mydas) and loggerhead (Caretta caretta) turtles to and from eastern Australian rookeries. Australian Wildlife Research: in press. COLIN J. LIMPUS and DARRYL REIMER, Queensland Turtle Research Project, Queensland Department of Environment and Heritage, P. 0. Box 155, Brisbane, 4002, AUSTRALIA. IV WORKSHOP ON PROGRAMS OF SEA TURTLE CONSERVATION 11-13 MARCH 1991, MERIDA, YUCATAN, MEXICO Since 1988, regional workshops have been held in Mérida, Yucatán, Mexico to review progress and problems from the past field season and to plan for the up-coming season. These workshops provide a forum where technicians, biologists, conservationists, and administrators involved in marine turtle conservation and investigation can freely exchange information, share ideas, discuss problems, and plan for the future. The workshops have progressively taken on 2 - Marine Turtle Newsletter, No. 56 more responsibilities and involved a wider variety of participants. The fourth workshop was coordinated, as usual, by CINVESTAV-Mérida (Centro de Investigacion y de Estudios Avanzados), a principal research institute in the region, and PRONATURA Peninsula Yucatán, one of the most active non-government organizations in Mexico. More than 80 people attended the 3-day event, which resulted in numerous articles in the local press. Invited talks were included in the agenda for the first time, and the first was by M. en C. Rene Marquez, who had just returned from Cuba where he had served as a sea turtle program adviser. He talked about problems regarding stock management and pointed out the need for basic demographic information. Size-frequency distributions of nesting females were offered as a means to understand adult survivorship, and also to serve as a basis from which to reconstruct earlier (unknown) aspects of the demographic profile. Biol. Isabel Aguirre then summarized the advances made since the first workshop. Having compiled the results of the third workshop (Aguirre 1990), she identified previous plans and proposals which had been implemented and those which had not. Among the successes were numerous examples of inter-institutional cooperation, a regional directory of persons and institutions involved in sea turtle work, development of environmental education projects, and new protection and monitoring efforts at several nesting areas. The major obstacle, she concluded, has been a lack of coordination. Specific proposals which have yet to be implemented include: establishing a regional data bank, standardizing data and techniques, establishing a functional marking program, writing and distributing reports and research results, and reducing the exploitation of sea turtles while providing viable alternatives to fishermen and artisans. M.V.Z. Georgita Ruíz spoke about WIDECAST (Wider Caribbean Sea Turtle Recovery Team and Conservation Network), a UNEP-sponsored effort in the Caribbean, and gave examples of progress that had been made throughout the Caribbean region. She explained the structure of the WIDECAST organization, emphasizing that it depends on volunteer participation and works directly through governmental and nongovernmental coordinators in individual countries or government regions. An outline of the "sea turtle recovery action plan" produced for each country was discussed in detail, reviewing point-by-point the information which is sought to complete the plan. She concluded that a great deal of work still needed to be done before a final "action plan" for a country as large and diverse as Mexico could be considered complete. She noted that a person, or organization, was needed to coordinate WIDECAST's Yucatán activities, emphasizing the need to consolidate information from the Peninsula. Biol. Raquel Briceño spoke on BITMAR (Banco de Información de Tortugas Marinas). She explained that it was composed of four main activities: numeric data bank, bibliographic data bank, document data bank, and a trimestral newsletter. The need to standardize information was again mentioned, and data forms were illustrated. The relationship between BITMAR and other national data banks was explained, and advances which had been made over the past year were described. It was explained that funding for BITMAR was well assured. Biol. Elvia Rodríquez spoke on the need to standardize the taking and reporting of data, particularly measurements. The value of measurements in studies of growth, demography and population characterizations was mentioned.