Sea Turtle Conservation on Bonaire. Sea Turtle Club Bonaire 1997. Project Report

The Sea Turtle Club Bonaire (STCB) is a non-governmental, non-profit organization. Its main goal is the conservation of the sea turtles that occur on Bonaire. To reach this goal, annual projects are undertaken, such as research and the promotion of public awareness on sea turtle conservation. The STCB undertakes research in order to monitor the nesting activity of the two sea turtles species which nest on Bonaire: the hawksbill turtle ( Eretmochelys imbricata ) and the loggerhead turtle ( Caretta caretta). Regular beach surveys are performed in order to locate and record the crawls. Nests are excavated to determine the number of eggs, the hatching success and to obtain information on the non-hatched eggs. Turtle nesting activity was observed from late April onward until December. A peak of activity was found in July and August. 54 crawls have been reported, made by an estimated number of eleven turtles. 72.2% of the reported nesting activity was situated on Klein Bonaire and 27.8% on Bonaire main island. Thirteen nests of the total of twenty estimated nests made in 1997 were found: six were nests of hawksbill and seven of loggerhead turtles. Two new sites were added to the list of potential nesting sites. On both sites, recent turtle activity was reported and on one of them an old nest was found. Compared to former years, these figures seem quite average. The number of crawls found in 1997 levels those found in 1993 and 1995. The high number of crawls recorded in 1996 (a total of 116) was striking though. Information on juvenile turtles around Bonaire is gathered by means of a divers’ and snorkelers’ sighting network. This year, the total number of sightings was 1464. This is an increase of 63.4% compared to last year. The quality of the data is influenced for a large part by the difficulty for divers to identify turtles and the distribution of the divers over the different dive sites. Though, given these two reasons, the network does not deliver imbiased data, the results gathered this year gave us a better insight in the behavior of the juvenile sea turtles. A photo identification project was started in 1995. Since then, a database has been made to identify individual sea turtles. After three years, some success can be reported. In this report, only preliminary results are shown. Next year’s project assistants will work out the precise data. Research also included two pilot studies, started this year. An effort was made to investigate the foraging ecology of the juvenile green ( Chelona mydas ) and hawksbill turtles in the coastal waters of Bonaire. Areas which are known to be frequently visited by hawksbill and green turtles were monitored. These included areas at the west coast of Bonaire (Andrea I and II, and Margate Bay) and on the north side of Klein Bonaire (Sampler) for the hawksbill turtle, and Lac Bay on the east side of Bonaire for the green turtle. No clear traces of predation of hawksbill turtles on sponges have been found. Information on feeding behavior of hawksbill turtles obtained through the sighting network did not support other studies in de Caribbean which demonstrated a clear preference for sponges. The expected feeding activity of green turtles in Lac Bay was not recorded either. It has become clear that in order to gather relevant data on this subject, methods must be adjusted. In order to educate local children on their natural environment, the STCB has cooperated in the organization of ‘Turtuganan di Boneiru’ with the Bonaire Marine Park (BMP) and the Tourism Corporation Bonaire (TCB) since 1995. It used to be a snorkel club for local schoolchildren. However, this year, an extended program on marine wildlife has been set up in cooperation with E. Scholtens, Coordinator Nature and Environmental Education Bonaire. Turtuganan di Boneiru now offers a variety of educational activities next to snorkeling. Many children attended the Turtuganan di Boneiru on a regular basis. Per afternoon, on average 22 children were present. In total, 82 children took part in the Turtuganan di Boneiru. To reach children throughout Bonaire, the program will be performed at different locations in the future. Sea turtles need clean beaches as debris may cause turtles to abandon nesting efforts. To improve the nesting habitat on Bonaire, the STCB organizes a coastal cleanup on an annual basis. This year, 150 volunteers gathered 809 bags of trash. Important information on the quantities and kinds of trash was recorded as well. This will be used to support requests to the government for deposits on products such as soda bottles. Klein Bonaire is an uninhabited islet in front of the West coast of Bonaire. It is the most important nesting habitat for sea turtles on Bonaire. Each year, 70-90% of the total nesting activity takes place on Klein Bonaire. However, it has been threatened with exploitation by the private owners. The STCB, together with other environmental organizations, devotes itself to the conservation of Klein Bonaire. A proposal to turn the 50 meter-zone beyond the shore line of Klein Bonaire into a national park has been presented to the Bonairean government. Every year, the STCB cooperates with many organizations. Again in this year’s project, assistance came from other NGOs and the local business community on Bonaire. However, a conservation project stretches beyond the local boundaries. Regional and international cooperation is necessary. This year, STCB Project Coordinator Niels Valkering met different people in Curaçao in order to discuss the status of the endangered sea turtles. He also attended the 18th International Symposium on Sea Turtle Biology and Conservation in Mexico. To keep the sea turtles from extinction, this kind of contact between organizations is very important. Regular exchange of information is necessary for the optimalization of the ongoing conservation program of the STCB.