Bay & Paul Foundation, Marine Turtle Conservation Fund and Norcross Wildlife Foundation

Transcription

1 REPORT ON THE 2009 GREEN TURTLE PROGRAM AT TORTUGUERO, COSTA RICA Submitted to Caribbean Conservation Corporation and the Ministry of Environment, Energy and Telecommunications of Costa Rica 31 July, 2010 by Clare Atkinson, Field Research Coordinator Laura Berrondo Ramos, Outreach and Education Coordinator Dr Emma Harrison, Scientific Director Ian Aspinall, Research Assistant Jose Alonzo Torres, Research Assistant Stella Maris Canevari, Research Assistant Dana Clark, Research Assistant Brian Drozd, Research Assistant Erick Duarte Betancourt, Research Assistant Phoebe Edge, Research Assistant Antonio Gómez Gómez, Research Assistant Celin Guevara Cortéz, Research Assistant Michael Howe, Research Assistant With assistance from Peter Kowalski, Research Assistant Petra Kranzfelder, Research Assistant Mandy Monroe, Research Assistant Steven O Connell, Research Assistant Mairon Ordoñez Ponce, Research Assistant Xochilt Pocasangre de Sermeño, Research Assistant Matías Pons Barrios, Research Assistant Daniel Struthers, Research Assistant Jorge Ivan Ramos, Track Surveyor With financial support from: Bay & Paul Foundation, Marine Turtle Conservation Fund and Norcross Wildlife Foundation Address: Apartado Postal NW 13 th St. Suite B-11 San Pedro Gainesville, FL COSTA RICA USA Phone: INT INT Fax: INT INT emma@cccturtle.org ccc@cccturtle.org Webpage:

2 Table of Contents TABLE OF CONTENTS... I LIST OF TABLES...II LIST OF FIGURES...II ACKNOWLEDGMENTS...1 EXECUTIVE SUMMARY INTRODUCTION METHODS Preparations Track Surveys Tagging of Nesting Sea Turtles Biometric Data Collection Fibropapilloma Assessment Determination of Nest Survivorship and Hatching Success Physical Data Collection Collection of Human Impact Data Environmental Education and Outreach Activities Independent Research Projects Satellite Tracking Project RESULTS Preparations Track Surveys Tagging of Nesting Sea Turtles Biometric Data Collection Fibropapilloma Assessment Determination of Nest Survivorship and Hatching Success Physical Data Collection Collection of Human Impact Data Environmental Education and Community Outreach Activities Independent Research Projects Satellite Tracking Project DISCUSSION Preparations Track Surveys Tagging of Nesting Sea Turtles Biometric Data Collection Fibropapilloma Assessment Determination of Nest Survivorship and Hatching Success Physical Data Collection Collection of Human Impact Data Environmental Education and Community Outreach Activities Independent Research Projects Satellite Tracking Project REFERENCES APPENDICES...57 I

3 List of Tables Table 1. Dead turtles encountered during the 2009 Green Turtle Program Table 2. Mean carapace length and clutch size of green turtles Table 3. Precision of carapace measurements for green turtle females Table 4. Mean carapace length of hawksbill females Table 5. Precision of carapace measurements for hawksbill females Table 6. Mean carapace length of leatherbacks Table 7. Fate, hatching and emerging success of marked green turtle nests in Table 8. Summary of excavation data for green turtle nests marked in Table 9. Incidence of albinism, twins and deformed embryos in Table 10. Summary of hawksbill nest excavations from Table 11. Summary of rainfall data January to December, Table 12. Summary of air temperature data January to December, Table 13. Mean monthly sand temperatures during the 2009 Green Turtle Program Table 14. Number of visitors to the CCC Natural History and Visitors Center Table 15. Number of paying visitors to Tortuguero National Park, Table 16. Room and bed capacity of the hotels and cabinas in the Tortuguero area Table 17. Number of visitors participating in turtle tours in Table 18. Hatchling disorientation observed during the 2009 Green Turtle Program Table 19. Summary of environmental education activities conducted during the 2009 Green Turtle Program Table 20. Duration of different phases of the nesting process for turtles subject to different levels of tourism impact data from 2008 and List of Figures Figure 1. Temporal distribution of green turtle nesting at Tortuguero in 2009, as determined from weekly track surveys Figure 2. Green turtle nesting trend at Tortuguero, , as determined by weekly track surveys of the entire beach Figure 3. Spatial distribution of green turtle nesting at Tortuguero in 2009, as determined from weekly track surveys Figure 4. Leatherback nesting trend at Tortuguero, , as determined by weekly track surveys Figure 5. Results of daily track surveys of the northern 5 2/8 miles of beach in Figure 6. Illegal take of green turtle nests and females in 2009, as determined from daily track surveys of the northern 5 2/8 miles of beach II

4 Acknowledgments The 2009 Green Turtle Program was conducted under a research permit from the Tortuguero Conservation Area of the Ministry of Environment and Energy of Costa Rica, detailed in resolution N o ACTo-GASP-PIN This report was made possible thanks to the dedication of the 2009 Green Turtle Program research team; all the data presented here were collected by Field Research Coordinator (FRC) Clare Atkinson and Outreach and Education Coordinator (OEC) Laura Berrondo Ramos, and the dedicated team of Research Assistants (RA): Ian Aspinall (Costa Rica), Jose Alonzo Torres (Costa Rica), Stella Maris Canevari (Argentina), Dana Clark (New Zealand), Brian Drozd (USA), Erick Duarte Betancourt (Costa Rica), Phoebe Edge (UK), Antonio Gómez Gómez (Spain), Celin Guevara Cortéz (Venezuela), Michael Howe (Australia), Peter Kowalski (Canada), Petra Kranzfelder (USA), Mandy Monroe (USA), Steven O Connell (USA), Marion Ordoñez Ponce (Costa Rica), Xochilt Pocasangre de Sermeño (El Salvador), Matías Pons Barrios (Uruguay) and Daniel Struthers (UK). In addition, we also gratefully acknowledge the assistance of Tifanny Barboza and Andrea Herrera, students from the Siquirres Technical College, who conducted their six-week practical placement during October - November, 2009, and the many volunteer participants who aided in data collection throughout the Program. The weekly track surveys of the entire beach were conducted by Jorge Ivan Ramos, whose considerable efforts we very much applaud. The hard work of all the John H. Phipps Biological Station staff was crucial to the success of the 2009 Green Turtle Program. Station manager Juan Carlos Cordero supervised the running of the station; Katherine Rodriquez and Adrianne Pacheco administrated the visitor center; boat captain Jorge Ivan Ramos safely transported researchers on the canals; Marcela Castellón made sure that everyone was well fed; Jeanette Molina and Yadile Rivera were responsible for keeping the station clean and ensuring that everyone had clean clothes; and the station was kept secure, day and night, by security personnel José Lara and Jorge Luis Vasquez. Mr. Eduardo Chamorro and the dedicated park rangers of the Tortuguero Conservation Area (ACTo) are due acknowledgement for their on-going efforts in reducing threats to sea turtles in Tortuguero National Park and surrounding areas. Also, the assistance of the park rangers, the Tortuguero Tour Guide Association and personnel of the Turtle Spotter Program, in helping to maintain a controlled tourist presence on the beach is much appreciated. In addition, the CCC would like to acknowledge the residents of Tortuguero, in particular Enrique Obando, for their continued support throughout the 2009 Green Turtle Program. Our outmost gratitude is extended to National Director Roxana Silman and her assistant Maria Laura Castro in San José, who provided complete logistical support throughout the Program. The help of CCC staff based in the Gainesville, Florida office is also recognized. For financial assistance we would like to thank the Bay & Paul Foundation, the Firedoll Foundation, the Marine Turtle Conservation Fund, the Marisla Foundation, the Norcross Wildlife Foundation and all the 2009 Green Turtle Program participants. 1

5 Executive Summary Monitoring and Research Activities Conducted 1 During 2009, a total of 52 track surveys were conducted along the entire 18 miles of beach between Tortuguero river mouth and Jalova lagoon. 2 Green turtle nesting was observed between April and December, 2009; with the first nest recorded on 4 April. 3 Peak nesting was recorded on 13 September; 2,161 green turtle nests were counted in a single night. 4 An estimated 109,741 green turtle nests were laid during This equates to a population of 18,290 39,193 nesting females. 5 A total of 14.7% of all green turtle nests recorded during track surveys were deposited between Tortuguero river mouth (mile 3/8) and mile 5, where all night patrols took place. 6 Jaguars killed a minimum of 37 green turtles in 2009; on 8 November five turtles were killed in a single night. 7 Hawksbill nesting density was very low throughout the season, with six nests recorded in May and June; on 25 June three hawksbill nests were counted from one night. 8 During daily track surveys conducted by RAs between 15 June and 2 November a total of 17,165 green turtle nests and 14,286 green turtle false crawls were recorded between the Tortuguero river mouth and the mile 5 marker. 9 Six leatherback and 18 hawksbill nests were recorded green turtle, one leatherback and two hawksbill nests were recorded as poached during daily track surveys. 11 Fourteen adult green turtles and one hawksbill were poached from the beach. 12 Illegal poaching activity was observed on 41.1% of surveys. 13 1,714 team hours of night patrols were conducted from 11 June 30 October. 14 A total of 1,025 green turtles were newly tagged, 594 green turtles had tags, and 379 females were encountered more than once during night patrols. 15 Ninety-two of the previously tagged turtles had been originally tagged more than 10 years ago and nine more than 20 years ago. 16 The longest nesting history for a turtle observed in 2009 was a turtle that was originally tagged in 1982, 27 years ago. 17 Thirty-two green turtles were encountered in 2009 with tags from other projects; six were tagged in Pacuare Nature Reserve, five in Mondonguillo, two in Parismina and 19 in Caño Palma. 18 Two turtles were encountered with tags from locations outside of Costa Rica; one from Belize, the other from Mexico. 2

6 19 Newly tagged green turtles had evidence of old tag holes or notches in at least one front flipper in 16.6% of cases. 20 Tagging efficiency for night patrols varied from %, with a mean of 9.2%, for nights preceding track surveys. 21 Green turtles encountered during night patrols nested in the open zone in 25.1% of cases (n = 495), 56.1% (n = 1,104) were located in the border zone and 13.7% (n = 270) in the vegetation zone. 5.1% of turtles were encountered during a false crawl emergence (n = 100). 22 Two newly tagged and four previously tagged hawksbill turtles were encountered during the 2009 Green Turtle Program. 23 Four hawksbills nested successfully; one nest was laid in the open zone, three were in the vegetation zone and two females did not lay. 24 Five leatherback turtles were encountered during the 2009 Green Turtle Program; one was tagged in Tortuguero in 2006, one in Tortuguero in 2007, two females were originally tagged in Parismina and one female was tagged in Pacuare Nature Reserve. 25 Overall carapace length for green turtles was 105.4cm (CCLmin) and 98.7cm (SCLmax). 26 Mean clutch size for green turtles was eggs. 27 Precision of CCLmin and SCLmax measurements of green turtles was the same within a single encounter; 0.4cm. For turtles seen more than once, SCLmax measurements were more precise. 28 Mean carapace length for hawksbill turtles was 86.8cm (CCLmin) and 83.4cm (SCLmax). 29 Mean clutch size for hawksbill females was 165 eggs. 30 Mean carapace length of leatherbacks was 150.4cm (CCLmin). 31 Clutch size for one leatherback nest was 76 yolked and 12 yolkless eggs. 32 Of 72 green turtles carefully examined for the presence of fibropapilloma tumors none were recorded with tumors. Only one turtle was observed with a small tumor on her front flipper. 33 A total of 173 green turtle nests were marked and the fate was determined for 110 nests. Overall mean hatching success is estimated at 77.6% and overall mean emerging success at 73.2%. 34 Four nests were partially depredated (n = 4); two nests (1.8%) were poached, while other nesting females disturbed or destroyed a further two nests. 35 Comparison between egg counts at excavation and the moment of oviposition showed a mean difference of 4.7 less eggs counted at the time of the excavation. 36 Mean depth for undisturbed green turtle nests at excavation was 57.8cm (n = 83) from the sand surface to the top egg and 73.6cm (n = 85) to the bottom of the egg chamber. 37 A total of six albino and one deformed embryo were observed in unhatched eggs, accounting for 0.06% of eggs. 38 Two hawksbill nests were monitored and their fate determined; both were undisturbed. 3

7 39 Hatching and emerging success of hawksbill nests (n = 2) was 84.7%. One nest contained 31 depredated eggs. 40 Mean depth to top egg for hawksbill nests was 50.0cm and to the bottom of the egg chamber was 57.0cm. 41 Rainfall was monitored from March - November 2009; November was the wettest month (885.6mm) and September was the month with least rain (145.3 mm). 42 Mean minimum air temperature was lowest in November (22.3 C); mean maximum air temperature was highest in April (29.0 C). 43 All the data loggers from the border and open zones were lost during the 2009 Green Turtle Program; only data from two loggers in the vegetation zone were recorded. 44 Mean monthly sand temperatures in the vegetation zone ranged from C. 45 A total of 27,565 persons visited the CCC Natural History and Visitors Center in 2009, a decrease of almost 2,000 people from numbers recorded in Tourist visitation to Tortuguero National Park (TNP) decreased significantly in 2009 (although data were only available from January November), to 107,261 paying visitors. Entrance fees to TNP (for the first 11 months of 2009) generated a total of 377,188,757 (~ US$673,070). 47 The capacity of hotels and cabinas in the Tortuguero available to tourists in 2009 was 689 rooms and to 1,456 beds. 48 A total of 34,805 tourists were issued permits to go on guided turtle tours in 2009; an average of 283 tourists per night during the green turtle season (July - October). The peak in tourist activity was on 11 August when 647 people participated in turtle tours. 49 The sale of brochures to fund the Turtle Spotter Program continued in 2009; 63.4% of tourists supported the program, raising $87,321 towards program expenses. Additional funds were used to build a new tourist waiting area, and for donations to TNP and the community of Tortuguero. 50 On only one occasion was evidence of hatchling disorientation caused by artificial lighting behind the beach observed; 18 live hatchlings were encountered and all made their way to the sea. 51 A coordinated environmental education program was carried out during the 2009 Green Turtle Program for students of the education establishments in Tortuguero and San Francisco. Activities were all conducted in the coastal communities of Barra del Colorado, Parismina and Moín. 52 The Junior Research Assistant Program ran for a second year; 15 students completed a series of different practical and theoretical assignments. 53 A fourth veterinary spay/neuter clinic was conducted September; 59 animals were castrated and 134 received medication for parasites. 54 One independent research project was conducted in 2009, continuing the study of the effect of tourists on the nesting behavior of females, and the survivorship and hatching success of nests. 55 Two satellite transmitters were attached to green turtles in July, 2009 to observe their behavior during the inter-nesting period, and post-nesting migrations; both were tracked to feeding grounds in Nicaragua. 4

8 Conclusions 1 The pattern of green turtle nesting was similar in 2009 to that observed in previous years, with most nesting occurring between July and October, and peaking in mid September. 2 The nesting trend for the green turtle population of Tortuguero continues to show an increase; continuing the pattern observed since surveys of the entire beach began in Daily track surveys provide detailed information about the illegal take of green turtle females and nests; information that is useful for the administrators of Tortuguero National Park, to effectively protect sea turtle populations. Poaching levels observed in 2009 were lower than those recorded in Biometric data show that the size of nesting females within the Tortuguero green turtle population remains constant each year. 5 Very few hawksbill turtles were observed in 2009; every effort should be made by research teams to encounter nesting hawksbills during patrols. 6 Environmental data collected at Tortuguero each year provide important baseline data on changes in rainfall, air temperature and sand temperature over the last 11 years. 7 Tourist visitation to CCC Visitor Centre and Tortuguero National Park decreased sharply in The Junior Research Assistant Program continued to involved local high school students in the monitoring activities of CCC; it also provided an opportunity for the OEC, FC and RAs to develop closer links with the community. 9 Continued research on the effects of tourism on green turtle nesting behavior provided supportive evidence that females alter their camouflaging behavior when large numbers of tourists are present; such results will help CCC provide technical recommendations to the Turtle Spotter Program Committee regarding management of tour groups on the beach. 10 Satellite tracking of green turtles from Tortuguero provided information about inter-nesting and post-nesting migratory behavior. Recommendations 1 The extended RA training and orientation program should be continued in future years as it gives RAs a more in-depth introduction to Tortuguero and the National Park, and provided more opportunity for group interactions during the first few weeks. 2 Reflective tape or paint for the mile markers might assist the RAs to locate themselves on the beach during night patrols. 3 Adequate training of RAs in all aspects of the monitoring protocol is essential to ensure that they are tagging and collecting data effectively and accurately; increased practical sessions should be scheduled during the orientation period, with on-going supervision throughout the program. 4 The weekly track surveys are vital for the continued evaluation of long-term trends of turtle populations at Tortuguero. 5 It is important that all data regarding illegal take of turtles and nests be provided to the relevant 5

9 enforcement authorities. It would be advisable to inform not only the Ministry of Environment, Energy and Telecommunications (MINAET), but also the Coast Guard, to ensure adequate patrols both on land (to protect nesting females) and at sea (to protect males and females in near-shore waters). 6 There is a continued need for increased coordination and data exchange between sea turtle conservation and monitoring projects being conducted throughout the Caribbean. 7 The veterinary clinics should be continued in future years and CCC should remain involved in the committee organizing the campaign to try and reduce the number of dogs in the community. 8 Collection of physical data should continue on a daily basis throughout the year, to monitor changes in environmental conditions in Tortuguero and provide a baseline for possible studies into the effects of climate change on sea turtles and their habitats. 9 The Turtle Spotter Program should continue in future years and CCC should remain responsible for the evaluation of the program activities and further studies to monitor potential negative impacts on turtles and their nests. It is important that CCC remains an integral part of the committee responsible for overseeing the development and implementation of the program activities. 10 With assistance from the turtle spotters, tourists should not be shown hawksbill turtles, to allow CCC researchers priority access nesting females, to increase the amount of data available for this critically endangered species. 11 Following the results of the study into the effect of tourist presence on the nesting behavior of green turtles conducted in 2008 and 2009, CCC recommends that a maximum of 20 people be permitted to observe each turtle. 12 A structured program of environmental education activities within the community should be continued, and further developed to include a broader section of the population, not just children. CCC should continue its efforts to become more integrated with the community; to provide information about the work of CCC in the region and to invite interested persons to participate in the monitoring activities. Having a dedicated Outreach and Education Coordinator facilitates community activities and should be contracted in future, funding permitting. 1. Introduction Dr. Archie Carr began studies of green turtles (Chelonia mydas) in Tortuguero in 1954 (Carr et al. 1978). Since 1959, the Caribbean Conservation Corporation (CCC) has implemented the annual Green Turtle Program. Prior to the 1998 nesting season, CCC staff and the Scientific Advisory Committee revised the Green Turtle Program monitoring protocol. The new protocol defines that the Green Turtle Program is conducted in order to fulfill CCC s scientific mission in Tortuguero: CCC will provide the scientific information necessary to conserve the populations of sea turtles that nest at Tortuguero, Costa Rica, so that they fulfill their ecological roles The 2009 Green Turtle Program represents the eleventh consecutive year of implementing the revised monitoring protocol. The objectives of this report are to summarize and discuss the results of the 2009 Green Turtle Program and provide recommendations for future sea turtle programs, conservation efforts and research activities in Tortuguero. 6

10 2. Methods 2.1 Preparations At the start of the 2009 Green Turtle Program the RAs completed an extensive orientation and training program; they received lectures about sea turtle biology and conservation, and the Green Turtle Program monitoring protocol was explained in detail by the FRC. The RAs were also introduced to key members of the community, including staff at the National Park ranger station. They learned about the history of the National Park, environmental laws relating to sea turtles, and the historical development of Tortuguero. They were also taken on a canal tour to learn about the flora and fauna of the park. In addition to the practical and theoretical training the RAs checked the position and condition of the beach markers in the northern five miles of beach (from the river mouth to the mile five marker); any missing markers were replaced and all markers were repainted white, with the mile numbers in black. 2.2 Track Surveys Weekly track surveys Track surveys were carried out approximately weekly during the entire Green Turtle Program. The track surveyor conducted surveys between the Tortuguero river mouth (mile -3/8) and Jalova lagoon (mile 18). The surveys commenced at dawn (4:30-5:00am) at the Tortuguero river mouth, or at Tortuguero village, and finished between 9:30am-12:00pm at Jalova lagoon. If the survey started at the village, and the section between Tortuguero river mouth and the village had not been surveyed in the morning, the same person surveyed that beach section upon completing the other part of the survey. Only tracks from the previous night were recorded and for each track the following information was recorded: Species Mile Nest or false crawl If the nest and/or turtle was poached If the turtle was depredated by jaguars A nest was recorded as poached if there were signs of human disturbance, including footprints around the nest, poke holes from a stick, evidence of digging, an empty egg chamber or fresh broken egg shells close to the nest. A turtle was considered poached when there was no down track heading back to the sea and there was evidence that she had been flipped over and dragged off the beach (either through the vegetation or to a boat). Dead turtles were considered depredated by jaguars (Panthera onca) when they were surrounded by jaguar tracks or showed characteristic jaguar injuries, such as extensive bites marks to the neck Daily track surveys In addition to the weekly track surveys of the entire 18 miles of nesting beach the FCs and RAs conducted daily track surveys along the northern 5 2/8 miles of beach (from the Tortuguero river mouth to the mile 5 marker) from June - October. These surveys commenced at 6.00am each morning. 7

11 Only tracks from the previous night were counted, and for each track the following information was recorded: Species Mile Nest or false crawl Once a nest had been recorded two lines were drawn through the track to ensure that it was not counted on future surveys Illegal take and nest predation During track surveys researchers also recorded the level of illegal take of nests and nesting turtles and depredation. For each nest the following information was recorded: Species Mile If the nest and/or turtle was poached by humans If the nest was predated Identify the predator if possible Dead turtles Any dead turtles encountered during track surveys were examined and an attempt was made to determine the cause of death. For each turtle the following information was recorded: Species Mile Sex if possible to determine If the turtle was killed by a jaguar Cause of death if possible to determine Presence of flipper tags numbers recorded if present Other pertinent observations 2.3 Tagging of Nesting Sea Turtles Tagging teams patrolled the beach every night from June - October. The northern part of the beach was divided into two sections: Boca - from the river mouth to the field station (at mile 2 5/8) and Park - from the field station to the mile 5 marker. Separate teams patrolled each section during two shifts: 8pm - 12am and 12-4am, when the number of researchers and volunteer participants allowed. Female turtles encountered during the patrol were tagged after finishing oviposition or when returning to the sea. Leatherbacks (Dermochelys coriacea) were tagged in the rear flippers; green and hawksbill (Eretmochelys imbricata) turtles were tagged axillary, close to the first scale on the front flippers. All turtles were double-tagged to allow identification even if one tag was lost between nesting emergences. For each encounter the following information was recorded: Date 8

12 Mile marker (to the north of the turtle) Species Tag numbers of existing tags and/or evidence of old tag holes or notches The location of the nest was classified into one of three groups: Open open beach with no vegetation and no shading Border nest partially shaded by vines or other sparse vegetation for some part of the day Vegetation dense vegetation completely shading the nest throughout the day Green turtles Inconel #681 tags were used to tag a minimum sample of 1,000 green turtles not carrying old tags. Every effort was made not to mix Inconel and Monel tags on the same individual. Thus, if a turtle was encountered carrying one Monel tag this was removed and two Inconel tags were applied. If it was not possible to remove the Monel tag for some reason, a second Monel tag was applied to the other flipper Hawksbill turtles Hawksbill turtles were tagged with Inconel #681 tags. Once tagged, a disposable sterile scalpel or a biopsy punch was used to collect tissue samples from all hawksbills encountered, when possible. The samples were stored in ethanol until the relevant CITES permits were obtained and then the samples were sent for genetic analysis to Dr Peter Dutton of the National Marine Fisheries Service. Due to the very low level of hawksbill nesting at Tortuguero, and the fact that they are listed as critically endangered, researchers always remained with the turtle until she returned to the sea and then they thoroughly erased the track afterwards, to minimize the possibility of the nest being taken by poachers Leatherback turtles Leatherback turtles were tagged in the rear flippers using Monel #49 tags. 2.4 Biometric Data Collection Green turtles Biometric data were collected from a sample of nesting green turtles. An attempt was made to count one clutch of eggs per night in each of the two beach sections (Boca and Park). Eggs counts were conducted as the eggs were laid, by a person wearing a plastic glove so as not to contaminate the nest. Eggs were counted using an egg counter; any yolkless eggs were counted separately. All egg counts were conducted after midnight, when there were no tour groups present on the beach. All tagged turtles were measured after they had finished nesting, if possible. Curved carapace length minimum (CCLmin), from where the skin meets the carapace by the nuchal notch to the posterior notch between the supracaudals, along the midline, was determined to the closest millimeter using a fiberglass tape measure. Straight carapace length maximum (SCLmax), from the anteriormost edge of the carapace to the posterior tip of the longest supracaudal, was determined, to the closest millimeter, using a set of calipers. Both CCLmin and SCLmax measurements were taken three times by the same person, whose name was recorded in the field book, in order to determine the precision of the measurements. Precision is defined as the difference in centimeters between the longest and the shortest of the three measurements. Precision for females encountered more than once during the 2009 season is defined as the difference between the shortest and the longest of all measurements taken from the same turtle over the course of the season. 9

13 2.4.2 Hawksbill turtles CCLmin and SCLmax measurements were taken for all hawksbills encountered during night patrols. As for green turtles, the same observer measured the turtle three times for each measurement, to allow the precision to be calculated. Whenever possible the clutch was counted, if the hawksbill had not already started to lay eggs when encountered Leatherback turtles For leatherbacks, CCLmin (from where the skin meets the carapace by the notch of the neck to the posterior end of the caudal projection, next to the central ridge) was measured using a 300cm fiberglass measuring tape. Each turtle was measured three times to determine an average CCLmin. No SCLmax measurements were taken as the calipers were not sufficiently large enough to measure a leatherback turtle. 2.5 Fibropapilloma Assessment For a minimum sample of 100 green turtles, those for which clutches were counted, an examination for fibropapilloma was also conducted. All soft body parts, including the cloacal region, were inspected for tumors, using a flashlight with a red filter. The following data were recorded for each assessment: The absence or presence of fibropapilloma tumors Location of fibropapilloma tumors Size of any tumors detected The name of the person examining the turtle Any evidence of fibropapilloma tumors on turtles for which the clutch was not counted was also recorded during the season. 2.6 Determination of Nest Survivorship and Hatching Success A sample of green turtle and hawksbill nests was marked during oviposition. These nests were all located between Tortuguero river mouth (mile -3/8) and the mile 5 marker. The nests were marked using three pieces of flagging tape that were attached to vegetation behind the nest. While the turtle was laying eggs the distance from the centre of the egg chamber to each of these tapes was measured to the nearest centimeter, so that the location of the nest could be determined at the time of excavation using triangulation. Three marker tapes were used to compensate for the loss of any tapes as a result of camouflaging turtles, insects or persons removing the tapes intentionally; if one marker tape was lost it was still possible to locate the nest using the other two tapes. The distance to the most recent high tide line was also recorded at the time of oviposition. In previous years nests have been excluded from the analysis of survivorship and hatching success because it was not possible to confirm that the excavated nest was in fact the original marked nest (high nesting density can result in other females laying eggs on top or very close to a marked nest). To assist in the positive identification of the marked nest during excavation a small piece of flagging tape with the nest code written on it was deposited in the egg chamber during oviposition. In addition, the morning after a nest was marked the measurements were checked to ensure that they crossed; any discrepancies were checked by the researchers responsible for marking the nest the previous night. In this way, erroneous measurements, or errors during the recording of data in the field books could be identified and corrected immediately. All of the marked nests were inspected daily at 6:00am. Evidence of depredation, poaching or beach 10

14 erosion were noted and resulted in termination of monitoring for that nest; if the evidence was inconclusive, monitoring continued as normal, but the date of the observed disturbance was recorded, so that any resulting anomalous excavation data could be accounted for. If evidence of hatching was observed, the date was noted and the nest was excavated two days later. If no depression or hatchling tracks were recorded, the nest was excavated after 65 days (75 days for any leatherback nests). After 65 days, or sooner if signs of emergence had been recorded, the nest was excavated, once the distances from the marker tapes had been re-measured to confirm that it was the original nest. Nests that had no obvious depressions were located by probing for soft sand using a wooden stick (only after 65 days, when it was presumed that hatching and emergence had occurred), and this technique greatly aided in locating several of the marked nests. The excavation was discontinued if the researcher encountered a large number of hatchlings in the nest; in such cases the hatchlings were re-buried and the nest excavated at a later date. If a few hatchlings were encountered, they were placed in a shallow hole close to the nest site and covered with sand so that they could reach the sand surface and emerge the following night. For each nest the following information was recorded during the excavation: Nest code Mile marker Name of persons conducting excavation Date laid, hatched (if available) and excavated Number of empty shells only shells corresponding to more than 50% of the egg were counted Number of hatchlings alive or dead Number of unhatched eggs - these were categorized as o Without embryo no visible embryo observed o Embryo an embryo at any stage of development was present o Full embryo a fully developed embryo was present Number of pipped eggs embryo had broken the shell but failed to hatch Number of predated eggs Number of deformed embryos including albinism or multiple embryos in a single egg Number of yolkless eggs If the nest identification tape was found Any other pertinent information In addition, the depth from the surface to the top of the egg chamber (to the first egg encountered), and the bottom of the egg chamber (after the last egg was removed) was measured to the nearest centimeter. If a nest could not be found when excavated, an additional attempt was made the following morning by a different research team. If after two attempts the nest could not be found, researchers tried to determine the fate of the nest. Nests were considered poached if an empty egg chamber was encountered. Nests were assumed dug-up by another turtle if broken eggshells and/or the nest code tape from within the egg chamber, and a new body pit were encountered where the original nest was supposed to be located. Nests were considered depredated if a large number of opened eggshells were found in close proximity to the location of the marked nest, and there were signs of digging by animals, or tracks. An attempt was made to identify the predator if possible. If human footprints and digging was observed at the location of the nest, the nest was considered dug-up by tour guides or other persons to show the hatchlings to tourists. Nests for which the fate could not be determined with certainty or which were not excavated entirely were excluded from the subsequent analysis of nest survivorship and hatching success. 11

15 2.7 Physical Data Collection Throughout the 2009 Green Turtle Program several environmental variables were monitored on a daily basis at the John H. Phipps Biological Station in Tortuguero. Rainfall was collected in a gauge that was emptied each day at 9.00am and recorded to the closest 0.1mm. Air temperature was recorded at 9.00am; the minimum and maximum values for the previous 24 hours, and the current temperature were noted. Sand temperature was measured using data loggers buried at 30, 50 and 70cm depth in the open, border and vegetation zones of the beach in front of the CCC station. The data loggers were set to take a temperature reading every hour. The data were downloaded in the middle and at the end of the 2009 Green Turtle Program. 2.8 Collection of Human Impact Data Visitors to CCC Visitors Centre The number of visitors paying to enter the CCC Natural History and Visitors Center was recorded each day during 2009 by the Visitor Center Administrator Visitors to Tortuguero National Park Staff at the Tortuguero National Park headquarters at Cuatro Esquinas provided information on tourist visitation to the park during Capacity of hotels and cabinas To monitor the growth of tourism development in Tortuguero a survey was conducted on the capacity of the hotels and cabinas in the region. The FRC (Clare Atkinson) and OEC (Laura Berrondo Ramos), collected information on the room and bed capacity from cabina owners and hotel managers in Tortuguero at the end of the 2009 Green Turtle Program Turtle tours The number of tourists going on guided turtle tours during the 2009 Green Turtle Program was calculated from the permits issued to tour guides by Tortuguero Conservation Area (ACTo). In 2009, the Turtle Spotter Program, the visitation system introduced in 2004 that aimed to reduce negative impacts of tourism on nesting sea turtles, was implemented for the entire northern five miles of beach where tourism is permitted (from the Tortuguero river mouth to the mile 5 marker). A new funding mechanism was implemented in 2007; an information brochure about the Turtle Spotter Program was designed and offered to tourists participating in turtle tours for a donation of $4. Each brochure contained a sticker which visitors were encouraged to wear during their tour, to show their support for the Program. Funds generated from these brochures were used to employ fourteen turtle spotters from the community of Tortuguero. The turtle spotters patrolled the beach searching for nesting turtles, and reported their location to the tour groups waiting with their guides at designated areas behind the beach. When the turtle was close to laying eggs, guides led their group to her location using a path behind the beach, thus reducing the number of people walking along the beach who could potentially disturb other turtles as they came ashore to nest. 12

16 2.8.4 Hatchling disorientation Any evidence of hatchling disorientation was recorded, for marked or unmarked nests. Where possible the light source causing the disorientation was noted, in addition to the number of disorientated hatchlings encountered (dead or alive) and the number of hatchlings that reached the sea successfully. 2.9 Environmental Education and Outreach Activities Presentations about sea turtle biology, conservation and the work of the CCC in Tortuguero were given opportunistically to groups staying at or visiting the John H. Phipps Biological Station. In addition, the 2009 Green Turtle Program RAs, supervised by the OEC Laura Berrondo Ramos, implemented a series of environmental education activities at the Tortuguero school and high school, and also at the school in San Francisco village. In response to concerns in 2007 from CCC, local guides and National Park staff about the level of dog predation of turtle nests and the increasing population of dogs in the village, a committee was organized comprising representatives from interested groups and individuals to coordinate a veterinarian spay/neuter clinic and educational program in 2008 with the aim of reducing the dog population and also providing advice to local residents on how to care for their pets. Two clinics were held in 2008; CCC remained an active member of the organizing committee throughout 2009, helping to plan and run two further clinics Independent Research Projects One independent research project was conducted during the 2009 Green Turtle Program which focused on the impacts of tourism on the nesting behavior of green turtles in Tortuguero. The project, a continuation of research initiated in 2008, was designed to gather information that could be used to help effectively manage the Turtle Spotter Program so that if fulfilled its objective of minimizing the negative impacts of tourism on sea turtles in the area Impact of tourist presence on the nesting behavior, survivorship and hatching success of green turtles Following the work of Catalina González Príeto in 2008, who found that turtle nesting behavior was significantly altered by the presence of more than 10 tourists, an undergraduate student from Canada (Peter Kowalski) decided to develop her study further and, in addition to observing the behavior of female green turtles subject to various levels of tourist impact during nesting, he marked the nest, monitored it during the incubation period and determined the emerging and hatching success through excavation (for methods see Section 2.6). For a minimum of 50 females, three different phases of the nesting process (oviposition, covering and camouflaging) were timed to the nearest second using a handheld stopwatch; the total number of people present around the turtle was also recorded. Only these phases of the nesting process were selected as tourists are not permitted to approach the turtle until she has started to lay her eggs. Subsequent analyses compared the behavior of females with respect to the number of people who had been present during the nesting process. The nests of at leasts 30 females were marked and monitored on a daily basis, and excavations conducted following emergence of hatchlings. Emerging and hatching success of nests laid by females observed by different numbers of tourists were subsequently compared Satellite Tracking Project In continuation with the satellite tracking project that has been conducted by CCC within the Caribbean region since 2001, in 2009 two satellite transmitters were available for attachment to green 13

17 or hawksbill turtles during the Green Turtle Program. These turtles were included in the 2009 Tour de Turtles; an on-line education event run by CCC to raise awareness about sea turtles, their migration behavior and threats that they face. The turtles in the Tour de Turtles compete to see which individual will be the first to swim 2,600km; each competitor has an independent sponsor, and has a cause for which they raise public awareness and funds. The transmitters were attached during the middle of the nesting season; the data would provide information on inter-nesting behavior between nesting emergences and also post-nesting migrations to feeding grounds away from Costa Rica. Turtles were selected by researchers depending on their size, physical characteristics of the carapace (to aid attachment by not having any deformities or irregularities in the scutes) and distance from the field station (to facilitate their relocation to the station where they were retained overnight). The following morning the transmitter attachment process began at 6.00am, following the protocol of Coyne et al.(2008): The turtle s carapace was cleaned of any epibionts and the surface abraded to ensure a good adhesion; it was then cleaned with acetone to remove dust and/or debris. An Epoxy adhesive was used to secure the satellite transmitter to the carapace of the turtle. The epoxy was allowed to dry completely and the turtle was released to the sea. Prior to the attachment of the transmitter the turtle was tagged and CCLmin and SCLmax carapace measurements were taken. Visitors from the lodges and cabinas, and members of the community were invited to observe the attachment procedure and release of the turtle. CCC researchers were available to answer any questions about sea turtles, satellite telemetry or the work of CCC. Data from the transmitters were used to produce migration maps which were regularly updated on the Tour de Turtles website ( 3. Results 3.1 Preparations The RAs arrived in Tortuguero on 8 June, During the first two weeks of the 2009 Green Turtle Program the RAs received an intensive training program and general orientation. This included lectures about sea turtle biology, conservation, tourism in Tortuguero, and the history and structure of CCC. There was also a detailed explanation of the Green Turtle Program monitoring protocol. In addition to theoretical instruction they also received practical training in flipper tagging, nest marking and other data collection procedures from the FRC. Training patrols were conducted on several nights along sections of beach close to the field station (between the Tortuguero river mouth and mile 5), during which the FRC demonstrated field techniques and supervised RAs tagging and measuring turtles, and recording data in the field books. To have a better understanding of the National Park, environmental laws and the community, the RAs spoke to park rangers and members of one of the founding families of Tortuguero to learn about the history and development of the area. To facilitate the environmental education program there were also visits to the school and high school in Tortuguero, and the school in San Francisco. RAs also visited the biological research station at Caño Palma to talk to investigators conducting sea turtle research north of the Tortuguero river mouth. 14

18 During the first week of the program the mile markers on the beach between the Tortuguero river mouth (mile -3/8) and the mile 5 marker were replaced and/or repainted as necessary, to ensure that there were three markers at each 1/8 of a mile. These markers were put in the same locations as those positioned at the start of the 2009 Leatherback Program. 3.2 Track Surveys Weekly track surveys Fifty-two weekly track surveys were conducted from 3 January to 27 December Nesting of green turtles was observed regularly from May - November (See Figure 1), although the first green turtle nest was recorded on 4 April. Peak nesting was observed on 13 September, when 2,161 nests were recorded in a single night. Using the methodology of Troëng & Rankin (2005), it was estimated that 109,741 green turtle nests were laid along the entire 18 miles of beach during the 2009 nesting season (See Figure 2). This equates to a population of between 18,290 39,193 nesting females. As observed in previous years, green turtle nesting density was found to be highest away from the river mouths that mark the end of the beach; the least stable area of nesting habitat (See Figure 3). Increased nesting was observed within Tortuguero National Park, between miles 5-13, with the highest density occurring close to the centre of the beach at mile 10 (almost 10% of nests were recorded within this mile). Nests laid between the Tortuguero river mouth and the mile 5 marker, where nightly beach patrols were regularly conducted, accounted for 14.7% of all nests laid on the entire beach (See Figure 3). On 16 August 160 green turtle nests were recorded as poached; this included all of the nests laid in mile 13, 13 4/8, 15, 15 4/8, and three nests from close to the Tortuguero river mouth at mile -1/8. Between 4 April (the first date that green turtle nesting activity was observed) and 20 December, the track surveyor reported a total of 37 green turtles that had been killed by jaguars the night before the survey. On five occasions more than three turtles were killed in a single night, including 8 November when five turtles were killed. As in previous years, very low levels of hawksbill nesting activity were recorded during the weekly track surveys throughout 2009; six hawksbill nests were observed between 2 May 25 June; on 25 June three hawksbill nests were recorded from one night. Leatherback nesting activity was observed from late February to early July, with peak nesting occurring on 11 April when eight nests were recorded. It was estimated that a total of 274 leatherback nests were laid in 2009 (See Figure 4); however results from track surveys conducted during the 2009 Leatherback Program suggest that more nests were actually laid. For a more detailed discussion of the temporal and spatial distribution of leatherback nesting in 2009, and levels of illegal take, see the 2009 Leatherback Program Report. 15

19 Figure 1. Temporal distribution of green turtle nesting at Tortuguero in 2009, as determined from weekly track surveys 3,500 3,000 2,500 2,000 1,500 1,000 Number of nests/false crawls Jan 17-Jan 31-Jan 14-Feb 28-Feb 14-Mar 28-Mar 11-Apr 25-Apr 9-May 23-May 6-Jun 20-Jun 4-Jul 18-Jul 1-Aug 15-Aug 29-Aug 12-Sep 26-Sep 10-Oct 24-Oct 7-Nov 21-Nov 5-Dec 19-Dec Date Nests False Crawls 16

20 Figure 2. Green turtle nesting trend at Tortuguero, , as determined by weekly track surveys of the entire beach 200, ,000 Estimated number of green turtle nests 160, , , ,000 80,000 60,000 40,000 20, Year 17

21 Figure 3. Spatial distribution of green turtle nesting at Tortuguero in 2009, as determined from weekly track surveys % of green turtle nests / Mile 18

22 Figure 4. Leatherback nesting trend at Tortuguero, , as determined by weekly track surveys 2,000 1,800 Estimated number of leatherback nests 1,600 1,400 1,200 1, Year 19

23 3.2.2 Daily track surveys Daily track surveys were conducted by the FRC, OEC and RAs between 15 June and 2 November (except 7 August, 20 October and 27 October). A total of 17,165 green turtle nests and 14,286 green turtle false crawls were recorded between the Tortuguero river mouth and the mile 5 marker (See Figure 5a and 5b); successful nesting was observed in 54.6% of green turtle emergences. Figure 5a shows the spatial distribution of green turtle nests and false crawls for the northern 5 2/8 miles of beach. Nesting density per 1/8 mile was greater within the National Park (past 3 3/8), except for mile 2/8. Subsequently the overall number of nests recorded was much greater within the limits of the park (54.7% compared to 45.3% outside the park). As in previous years, nesting density was lowest close to the river mouth (up to mile -2/8) and in front of Tortuguero village (miles 2 7/8-3 2/8). The temporal distribution of nesting for the 2008 Green Turtle Program is shown in Figure 5b. Peak nesting activity was recorded on 30 August, when 361 green turtle nests were counted from the previous night; more than 300 nests were also recorded on 26 and 28 August, and 2, 3 and 11 September. Nesting activity remained above 50 nests per night from 20 July - 21 October (except for 22 July and 8 October). Six leatherback nests and eight false crawls were counted during the same time period; the last nest was recorded on 16 July. Hawksbill nesting activity was observed from June to September with a total of 18 nests and 11 false crawls recorded during track surveys. The majority of nests were recorded between June and August; two nests were recorded on 3, 11 and 24 July. The last hawksbill nest was observed on 5 September Illegal take and nest predation During the daily track surveys researchers also noted the level of illegal take of both eggs and female turtles (See Figure 6a and 6b). In total, 133 green turtle nests (0.8% of the total number laid) were taken from June October; one leatherback and two hawksbill nests were also poached. Fourteen green turtles and one hawksbill turtle were recorded as poached from the nesting beach. From Figure 6a it can be seen that the majority of nest poaching occurred towards the Tortuguero river mouth, between mile -3/8 and mile 0 and close to the village (between miles 2 6/8 and 3 2/8). As in previous years there was also a sharp increase in the number of nests taken illegally around the limit of Tortuguero National Park, between miles 3 3/8-3 5/8. Poaching of nesting turtles was also concentrated in these two same areas of the beach (See Figure 6a). From 15 June - 2 November, poaching (of either nests or turtles) was observed during 58 of 141 (41.1%) track surveys (See Figure 6b). The highest number of poached nests was recorded on 28 August, when 10 green turtle nests were taken in one night. Poaching was observed throughout the nesting season although there seemed to be more consistent illegal take in August (See Figure 6b). On 17 June, a group of tourists witnessed a pair of mating green turtles being harpooned in front of the airport, at around 6.30am. Photographs taken by the tourists were included in a letter CCC sent to MINAET and the Coast Guard, demanding increased, coordinated protection efforts (See Appendix 1). Only three newly laid green turtle nests were recorded as depredated by dogs from June October; although this is probably a gross underestimation of the level of dog predation as groups of dogs were often observed by researchers during track surveys, occasionally with more than 10 individuals. It is likely that dogs are predating older nests, especially those close to hatching, and so researchers are not recording the number of nests being affected. 20

24 Figure 5. Results of daily track surveys of the northern 5 2/8 miles of beach in 2009 a) Spatial distribution 1,700 1,600 Number of nests and false crawls 1,500 1,400 1,300 1,200 1,100 1, /8-1/8 1/8 3/8 5/8 7/8 1 1/8 1 3/8 1 5/8 1 7/8 Nests 2 1/8 Mile False Crawls 2 3/8 2 5/8 2 7/8 3 1/8 3 3/8 3 5/8 3 7/8 4 1/8 4 3/8 4 5/8 4 7/8 b) Temporal distribution Number of nests/false crawls Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug 31-Aug 7-Sep 14-Sep 21-Sep 28-Sep 5-Oct 12-Oct 19-Oct 26-Oct 2-Nov Date Nests False Crawls 21

25 Figure 6. Illegal take of green turtle nests and females in 2009, as determined from daily track surveys of the northern 5 2/8 miles of beach 18 a) Spatial distribution Number of nests/turtles /8-1/8 1/8 3/8 5/8 7/8 1 1/8 1 3/8 1 5/8 1 7/8 2 1/8 2 3/8 2 5/8 2 7/8 3 1/8 3 3/8 3 5/8 3 7/8 4 1/8 4 3/8 4 5/8 4 7/8 Mile Nests Turtles b) Temporal distribution Number of nests/turtles Jun 22-Jun 29-Jun 6-Jul 13-Jul 20-Jul 27-Jul 3-Aug 10-Aug 17-Aug 24-Aug 31-Aug 7-Sep 14-Sep 21-Sep 28-Sep 5-Oct 12-Oct 19-Oct 26-Oct 2-Nov Date Nests Turtles 22

26 3.2.4 Dead turtles During daily track surveys conducted during the 2009 Green Turtle Program seven dead green turtles were encountered; one of these had been killed by a jaguar, but the other six had either been killed by people or stranded on the beach (See Table 1). In addition, two dead green turtles were found by the police at a house in the village. Table 1. Dead turtles encountered during the 2009 Green Turtle Program Date Mile Species Sex Comments 22 June 4 Cm Male Washed ashore; no cause of death determined 22 June 4 4/8 Cm Male Washed ashore; no cause of death determined 5 July 4 3/8 Cm Female Washed ashore; no cause of death determined 6 Sep 3 7/8 Cm Female Killed by jaguar; found in vegetation; no tags present 10 Sep 4 5/8 Cm Female Washed ashore; no cause of death determined 2 Oct Unknown Cm Female Washed ashore; several days old; no cause of death determined 6 Oct Unknown Cm Female Two green turtles found by police at a house in the village 7 Oct 0 Cm Female Killed by people Cm = Green turtle 3.3 Tagging of Nesting Sea Turtles Tags used during the 2009 Green Turtle Program were National Band & Tag Company (NBTC) Inconel #681 tags , , , , Green turtles A total of 1,988 green turtle encounters were recorded during 1,714 team hours of night patrols between 11 June and 30 October 2006 (See Appendix 2). These encounters included 1,609 individual females; 1,015 (63.1%) initially observed without tags and 594 (36.9%) who had tags. In addition there were 379 encounters with turtles observed more than once during the 2009 nesting season. During the 2009 Green Turtle Program, 32 green turtles tagged at other nesting beach projects in Costa Rica were encountered; 19 were tagged by researchers from the Caño Palma turtle monitoring project (north of the Tortuguero river mouth), five were tagged in Mondonguillo, two in Parismina and six in Pacuare Nature Reserve, which are all beaches south of Tortuguero National Park. In addition there were two females encountered with tags from countries other than Costa Rica. One had tag number AK999, which is thought to have been used in Mexico; researchers have been contacted by the SD for information on when and where the tag was applied. The other turtle had tag number XXN904; Linda Searle, a biologist working for Ecomar in Belize, informed the SD that this turtle was one of five that were tagged between , as part of their Save a Sea Turtle Program. Money from tourist donations was used to purchase turtles from fishermen at the market in Belize City; these turtles were tagged and then released. This is the first record of one of the rescued turtles being encountered. 23

27 The other females that had tags were all originally tagged in Tortuguero. Eighty-two individuals had been tagged more than 10 years previously; of these eight were tagged more than 20 years ago. The female with the longest tagging history for 2009 was observed on 25 October; female with ID# was originally tagged in She has only been observed in three other nesting seasons in the intervening 27 years; 1986, 1988 and Of 966 newly tagged green turtles checked for the evidence of old tag holes or notches when encountered for the first time during the 2009 Green Turtle Program, 160 (16.6%) had evidence that they had been previously tagged in at least one flipper. Tagging efficiency for green turtles emerging (nests and false crawls) between the Tortuguero river mouth and the mile 5 marker on nights before track surveys from July thru October (n = 116) ranged from 0% to 36.4%, with an overall mean of 9.2%. Beach zone was recorded for 1,969 green turtles encounters; 25.1% (n = 495) of those females nested in the open zone, 56.1% (n = 1,104) were located in the border zone, 13.7% (n = 270) in the vegetation zone and 5.1% were encountered while making a false crawl (n = 100) Hawksbill turtles Six female hawksbill turtles were encountered during the 2009 Green Turtle Program (See Appendix 1). Of these, two were newly tagged, and four were previously tagged; one in Tortuguero in 2001, one in Tortuguero in 2003 and the other by researchers at Caño Palma. The one newly tagged hawksbill turtle checked for evidence of previous tags had no old tag holes or notches. Three of the females nested in vegetation zone (50.0%), one nested in the open zone (16.7%) and the other two (33.3%) individuals were encountered while making a false crawl Leatherback turtles A total of six leatherback encounters were recorded at the beginning of the 2009 Green Turtle Program; the last encounter was on 15 July. Five different females were observed; two were tagged in Tortuguero (one in 2006, one in 2007), two were tagged in Parismina and one was tagged in Pacuare. Four of the encounters were during successful nesting attempts; all nests were laid in the open zone. 3.4 Biometric Data Collection Green turtles Table 2 shows the mean carapace length and clutch size of green turtle females measured during the 2009 Green Turtle Program. To ensure independence of the data, only the first measurements taken for each individual were included in the analysis. The overall mean curved carapace length (CCLmin) was 105.4cm (Range = cm) and the overall mean straight carapace length (SCLmax) was 98.7cm (Range = cm). Previously tagged females were slightly larger than newly tagged individuals, but there was no difference between newly tagged females with or without evidence of previous tags (See Table 2). Clutch size ranged from eggs for all nests counted ( x = eggs, n = 86; See Table 2). Newly tagged females (with or without evidence of previous tagging) laid slightly larger clutches than previously tagged individuals (See Table 2). Not included in the estimation of average clutch size for newly tagged females were two nests in which the turtle laid only a very small number of eggs (10 and 16 eggs) before covering the nest and completing the nest process. For previously tagged females one 24

28 nest was excluded from the determination of average clutch size; the turtle abandoned the nest after laying only 16 eggs and proceeded to lay 16 more eggs on her way back to the sea. Table 2. Mean carapace length and clutch size of green turtles Sample Newly tagged females no OTH/OTN Newly tagged females OTH/OTN CCLmin / cm SCLmax / cm Clutch size / eggs n x ± S.D. n x ± S.D. n x ± S.D ± ± ± ± ± ± 25.5 Previously tagged females ± ± ± 20.9 All ± ± ± 19.5 OTH = Old tag hole, OTN = Old tag notch For green turtles CCLmin was measured with the same degree of precision for RAs and participants; SCLmax was measured with a slightly greater degree of precision by RAs than by participants (See Table 3a), although the range of precision values were similar for both groups. The two different carapace measurements taken during one encounter were equally precise (See Table 3a). Observer Table 3. Precision of carapace measurements for green turtle females a) During the same encounter CCLmin / cm SCLmax / cm n x ± S.D. Range n x ± S.D. Range Research assistants ± ± Participants ± ± Total ± ± b) Between encounters CCLmin / cm SCLmax / cm Encounters n x ± S.D. Range n x ± S.D. Range ± ± ± ± ± ± For females encountered and measured on two or more occasions in 2009, SCLmax measurements were taken with a higher level of precision than CCLmin measurements (See Table 3b). For both CCLmin and SCLmax measurements there were occasions when the difference between the length measurements on subsequent encounters with the same female was greater than 2cm (See Table 3b). 25

29 3.4.2 Hawksbill turtles Carapace measurements were only taken for three of the six hawksbill females observed during the 2009 Green Turtle Program (See Table 4). CCLmin ranged from cm and SCLmax from cm. Average size for the two clutches that were counted was 165 eggs. Sample Table 4. Mean carapace length of hawksbill females CCLmin / cm SCLmax / cm Clutch size / eggs n x ± S.D. n x ± S.D. n x ± S.D. Newly tagged females Previously tagged females ± ± All ± ± ± 36.8 Precision of SCLmax measurements of hawksbill females was slightly higher than that of CCLmin measurements (See Table 5); data from newly tagged and previously tagged females were combined. An inter-species comparison shows that the precision of SCLmax measurements is slightly greater for hawksbills than for green turtles; however, CCLmin measurements have a slightly higher precision for green turtles than hawksbills (See Table 3a and Table 5). Sample Table 5. Precision of carapace measurements for hawksbill females CCLmin / cm SCLmax / cm n x Range n x Range All Leatherback turtles During the 2009 Green Turtle Program biometric data were collected for four of the five leatherback females encountered; all of which were previously tagged (See Table 6). The overall mean carapace length (CCLmin) of leatherbacks was 150.4cm, with a range of cm (See Table 6). Only one leatherback clutch was counted; the female laid 76 eggs and 12 yolkless. The precision of leatherback CCLmin measurements was 0.4cm, with a range of cm. Sample Table 6. Mean carapace length of leatherbacks n CCLmin / cm x ± S.D. n Clutch size / eggs Normal eggs x ± S.D. Yolkless eggs x ± S.D. All ± Fibropapilloma Assessment A total of 72 green turtles were subject to a thorough examination for the presence of fibropapilloma tumors; no individuals were recorded to be affected with the disease. In addition to the females who 26

30 were checked specifically for the presence/absence of fibropapilloma, tumors were also recorded if encountered during the routine check physical abnormalities conducted on all females encountered. Only one female was found to have a fibropapilloma tumor; it was located on the front left flipper and measured 4 x 2cm. 3.6 Determination of Nest Survivorship and Hatching Success Green turtles A total of 173 green turtle nests were marked between 11 April and 30 September, 2009; three of which were marked during the 2009 Leatherback Program. Of these nests; 34 nests could not be found during the excavation and the fate could not be determined with certainty; another four nests could not be excavated as another turtle had laid a nest very close to the marked nest, so the excavation could not be conducted without disturbing the new nest; for four nests all three flagging tapes were lost; two nests could not be excavated as they were buried under logs and vegetation; one nest was disturbed by people after hatching; for four nests the triangulation measurements were recorded inaccurately; and for three others there were hatchlings still in the nest at the end of the Green Turtle Program on 30 November, In addition, two marked nests were eggs relocated by researchers; two nests contained very small clutches; for one nest only three eggs were found during excavation; in one nest only dead hatchlings were found during excavation; four nests were excavated, but two nests were found together, and for one nest the excavation data were not recorded correctly. These 63 nests, therefore, were excluded from subsequent analysis, leaving a sample of 110 green turtle nests monitored from the date of oviposition until their fates could be determined. Table 7 lists the fate of all of the green turtle nests marked in It can be seen that the majority of nests (included in the analysis) (77.3%) remained undisturbed during incubation (n = 85). Of those nests that were disturbed; predation accounted for 3.6% and poaching for a further 2.7%. Nesting turtles disturbed or destroyed 1.8% of marked nests, and nine nests (8.2%) were either unhatched or hatched but the hatchlings did not emerge. Fate Table 7. Fate, hatching and emerging success of marked green turtle nests in 2009 Boca n Park n Total n % of total Hatching success (%) Emerging success (%) 1. Undisturbed Partially excavated Hatched but did not emerge Partially depredated Unhatched Poached Disturbed by another turtle Destroyed by another turtle Total Calculated as the mean of all 110 nests 27

31 Table 7. Continued Not included in analysis Could not find at excavation All three tapes lost Measurements incorrect New nest close to marked nest Excavated two nests Live hatchlings in nest Small clutch Relocated nest Nest buried under vegetation Disturbed by people Only dead hatchlings found Only three eggs found Data recorded incorrectly Total Overall hatching success was calculated as 77.6% (n = 110) and overall emerging success was estimated as 73.2% (n = 110) (See Table 7). These values were determined as the mean of all 110 marked nests for which the fate could be determined. If the categories of poached, unhatched, disturbed by another turtle or destroyed by another turtle are removed from the determination of the overall hatching and emerging success the values are 82.0% and 77.3%, respectively. Data from the nest excavations of the 110 green turtle nests monitored through incubation are summarized in Table 8. 28

32 Table 8. Summary of excavation data for green turtle nests marked in 2009 Fate * n Hatchlings Live Dead Empty shells Pipped eggs No embryo Unhatched eggs Embryo Full embryo Depredated eggs Destroyed eggs Yolkless eggs , Total , * For fate code details see Table 6 29

33 Average clutch size (determined from egg counts conducted at the time of oviposition) was eggs (n = 104); this value includes nests that were subsequently excluded from the analysis of hatching and emerging success. Of the 110 nests included in the analysis of hatching and emerging success the majority (60.0%) were laid in the border zone (n = 66), 29 (26.4%) were deposited in the open zone and 15 (13.6%) were laid in the vegetation. There was no obvious correlation between nesting zone and the level of disturbance, ie. disturbed nests showed the same prevalence for the border zone as undisturbed nests. A comparison between egg counts at the time of oviposition and at excavation for a sample of undisturbed nests (n = 53) shows a mean of 4.7 fewer eggs counted at the time of excavation than at the time of oviposition (range: -35 to +56 eggs). The distance between the sand surface and the top eggshell at the time of excavation for undisturbed nests (n = 83) ranged between 11 and 86 cm with a mean of 57.3cm. The distance between the sand surface and the bottom of the egg chamber (n = 85) varied between 30 and 195 cm with a mean of 73.6cm. It was only possible to determine the incubation period for one nest; it was 70 days. Unhatched eggs that contained albino or deformed embryos accounted for only 0.06% of all eggs laid in undisturbed and disturbed nests that were excavated (See Table 9). Of the albino embryos three were found in the same nest. Table 9. Incidence of albinism, twins and deformed embryos in 2009 Type of abnormality n % of total Albino Deformed embryo Total Hawksbill turtles Three hawksbill nests were marked between May July 2009; only two of these were encountered during excavation. Both remained undisturbed during the incubation period, and hatched successfully. The results of the excavations of hawksbill nests are summarized in Table 10. Mean hatching success was 84.7% (range = 81.1% 88.2%) and emerging success was 84.7% (range = 81.1% %); these values were determined as the mean for both nests. One of the nests had a considerable number of depredated eggs (n = 31), and one of the females also laid two yolkless eggs in addition to the normal eggs. No deformed embryos or hatchlings were recorded. Table 10. Summary of hawksbill nest excavations from 2009 Fate 1 n Empty shells Hatchlings Live Dead No embryo Unhatched eggs Embryo Full embryo Pipped Depredated Hatching success % Emerging Success % For fate code details see Table 7 30

34 The mean distance between the sand surface and the top eggshell at the time of excavation for hawksbill nests (n = 2) was 50.0 cm (Range = cm). The mean distance between the sand surface and the bottom of the egg chamber was 57.0 cm (Range = cm) Leatherback turtles The hatching and emerging success of leatherback nests laid at Tortuguero during 2009 is discussed in detail in the 2009 Leatherback Report. 3.7 Physical Data Collection Rainfall Rainfall was recorded daily from January December, 2009, during the Leatherback and Green Turtle Programs (See Table 11). The driest month was May with a total of 208.8mm of rain recorded; the wettest month was November, with 937.4mm recorded during November. July was also a very wet month, with 833.2mm of rain. The total amount of rain recorded at the station during 2009 was 5,466.5mm; an average of 15.0mm per day. Average daily rainfall each month ranged from 6.7mm to 31.2mm per day (May and November, respectively). The highest rainfall recorded for a single 24 hour period was on 7 February, with 107.6mm. Table 11. Summary of rainfall data January to December, 2009 Month Total rainfall mm/month x rainfall mm/24 hours January February March April May June July August September October November December Total 5, Data for 48 hours 1-2, 24-25, 26-27, 28-29, January 2 Data for 48 hours 1-2, 3-4, 10-11, 25-26, 27-28; for 72 hours 14-16, and for 120 hours February 3 Data for 48 hours 30 April - 1 May 4 Data for 48 hours 12-13, July 5 Data for 48 hours 6-7, August 6 Data for 48 hours September 7 Data for 48 hours 5-6, 8-9, October 8 Data for 48 hours 31 October-1November, 3-4 November 9 Data for 168 hours 2-8 December and for 48 hours 10-11, December 31

35 3.7.2 Air temperature Minimum, current and maximum air temperature was recorded daily from January thru December, Mean monthly minimum and maximum air temperatures for 2009 are shown in Table 12. Table 12. Summary of air temperature data January to December, 2009 Month Mean minimum air temp / C Mean maximum air temp / C January February March April May June July August September October November December Overall mean Data for 48 hours 1-2, 24-25, 26-27, 28-29, January 2 Data for 48 hours 1-2, 3-4, 10-11, 25-26, 27-28; for 72 hours 14-16, and for 120 hours February 3 Data for 48 hours 30 April - 1 May 4 Data for 48 hours 12-13, July 5 Data for 48 hours 6-7, August 6 Data for 48 hours September 7 Data for 48 hours 5-6, 7-8, 20-21, October 8 Data for 48 hours 31 October-1November, 3-4 November and for 72 days 2-4 November 9 Data for 168 hours 2-8 December and for 48 hours 10-11, December Recorded air temperature ranged between 19 C and 31 C. February was the coolest month, with the lowest mean minimum and maximum temperatures (22.1 C and 25.1 C, respectively); April had the highest mean maximum temperature (28.9 C). The daily variation in temperature ranged from 0-11 C, with an average of 4.7 C difference between the minimum and maximum temperature recorded over a 24 hour period Sand temperature Mean sand temperatures recorded during the 2009 Green Turtle Program are shown in Table 13. Unfortunately all of the data loggers for the border and open zones (n = 6) were lost during the program; those in the border were possibly disturbed by another nesting turtle and then taken by people. Those in the open zone were either eroded by high tides or removed deliberately by people. In the vegetation zone, two data loggers were present; at 50cm and 70cm depth. Sand temperatures in the vegetation zone remained relatively constant from June November; at 50cm depth temperatures ranged from ºC, and at 70cm depth from ºC. Mean sand temperature from June thru November at 50cm and 70cm were 26.1ºC and 26.4ºC, respectively. 32

36 Table 13. Mean monthly sand temperatures during the 2009 Green Turtle Program Zone Vegetation x temperature / ºC Border x temperature / ºC Open x temperature / ºC Depth / cm June N/A N/A N/A N/A N/A N/A N/A July N/A N/A N/A N/A N/A N/A N/A August N/A N/A N/A N/A N/A N/A N/A September N/A N/A N/A N/A N/A N/A N/A October N/A N/A N/A N/A N/A N/A N/A November N/A N/A N/A N/A N/A N/A N/A Retrieval depth / cm 1 December N/A N/A N/A N/A N/A N/A N/A Overall mean N/A N/A N/A N/A N/A N/A N/A N/A = No data logger at that depth during that month 3.8 Collection of Human Impact Data Visitors to CCC Natural History and Visitor Centre The number of visitors paying to enter the CCC Natural History and Visitor Center in Tortuguero is shown in Table 14. In 2009, around almost 2,000 fewer visitors were recorded than in 2008; 27,565 compared to 29,536 respectively. This was the third successive year in which visitation to the center decreased. Table 14. Number of visitors to the CCC Natural History and Visitors Center Month Total x / day Total x / day Total x / day January 3, , , February 3, , , March 3, , , April 2, , , May 1, , June 1, , , July 3, , , August 2, , , September 1, , October 1, , , November 2, ,025, 68 1, December 2, , , Total 30, , ,

37 The pattern of visitation throughout the year was very similar to that observed previously, with most visitors coming in January March; this was followed by a decline from April to June. Increased numbers of visitors were reported in July and August, but another dramatic decrease occurred in September, with fewer than 1,000 people for the entire month. The mean number of visitors per day in 2009 ranged from 27 (September) to 132 (March), with an average of 76 visitors per day for the year, which was less than that recorded for 2007 and Only January and October showed a higher daily visitation rate in 2009 than in 2008 (See Table 14) Visitors to Tortuguero National Park Table 15 shows the annual visitation to Tortuguero National Park (TNP) in the last ten years. Unfortunately, data available from Tortuguero Conservation Area (ACTo) for 2009 only included January November. However, these values would suggest that visitation to TNP decreased in 2009, opposite to the trend that has been observed for the last 10 years. For the first 11 months of 2009, 107,261 people were registered by ACTo as having paid the entrance fee to the park. During 2009 visitors did not pay an entrance fee to enter Barra del Colorado Wildlife Refuge. The entrance fees to TNP for the first 11 months of 2009 generated 370,188,757 (~US$673,070) in revenue for the Ministry of Environment, Energy and Telecommunications (MINAET). Year Table 15. Number of paying visitors to Tortuguero National Park, Tortuguero National Park CR visitors Foreign visitors Total visitors Barra del Colorado Wildlife Refuge Total visitors TNP and BCWF Total fees raised ,543 36,354 41,897 2,639 71,409, ,175 39,057 45,232 2,941 76,556, ,745 44,594 50,339 3,999 98,495, ,643 59,026 67, ,715, ,545 71,912 81, ,313, ,292 77,791 87, ,347, ,257 80, , ,924, ,898 92, , ,368, , , , ,051, ,652 83, , ,188,757 Data from ACTo data is for January November only During 2009 it was brought to the attention of CCC that there had been a change to the way in ACTo staff were recording tourist visitation to TNP. Since 2006, guides and boat captains who enter the national park during canal tours have also been included in the value for national visitors. Thus, the apparent dramatic increase in Costa Rican nationals that was observed from 2005 to 2006 (See Table 14), does not represent an actual increase in the number of national tourists, but rather is an artifact of this change to the way in which data have been recorded. Thus, the values for Costa Rican tourists from should be viewed with caution as they are undoubtedly exaggerated. 34

38 3.8.3 Capacity of hotels and cabinas The number of hotel rooms available to tourists in Tortuguero in 2009 increased only slightly from 2008; 689 rooms compared to 675, respectively (See Table 16). Only a couple of the hotels/cabinas constructed more rooms. There was, however, a decrease in the number of beds available (from 1,519 to 1,456, respectively); this is due to the fact that several of the larger hotels/lodges altered rooms from triples to doubles, although some of the cabinas actually increased the number of beds available. Very few of the hotels or cabinas made extensive changes to their properties during In 2009 the smaller cabinas in the village accounted for approximately the same percentage of the overall room capacity as in 2008 (24.8% compared to 24.2%, respectively). Laguna Lodge added another 10 rooms, although it reduced the number of beds; it remains the biggest hotel, with 110 rooms (21.2% of the total room capacity of the lodges). The Lapa Verde cabina continues to rent exclusively to local community members. Table 16. Room and bed capacity of the hotels and cabinas in the Tortuguero area Hotel / Lodge Rooms Beds Cabina Rooms Beds Anhinga All Rankin Lodge Evergreen Aracari Ilan-Ilan Balcón del Mar 4 10 Baula Cabinas Tortuguero Laguna Casa Marbella Manatus La Casona Mawamba Hostel el Icaco Pachira Meryscar Samoa Miss Miriam 6 12 Tortuga Miss Miriam # Turtle Beach Lodge Miss Junnie s Hotel Total Hotel/Lodge 518 1,074 Princesa 8 22 Princesa del Rio 8 14 Princesa Resort Taylor s Place 3 5 Tropical Lodge 8 20 Total Cabina Total 689 Rooms, 1,456 Beds Lapa Verde CCC Rented exclusively to locals 2 Only available to CCC volunteer participants Turtle tours Since 2005 the Turtle Spotter Program (TSP) has been implemented along the entire 5-mile stretch of beach (from the Tortuguero river mouth to mile 5) where tourism is permitted by MINAET. In 2009, CCC continued to play a central role in the TSP committee, along with representatives from ACTo, the 35

39 Tortuguero Development Association, the Tour Guide Association and the local hoteliers. In 2009 no Coordinator was hired for the TSP; daily supervision of the turtle spotters and program activities were conducted by a member of TNP staff. Fourteen turtle spotters were hired for the official green turtle season (1 July 31 October). Of these 14, one was designated as the Supervisor, who helped oversee the other turtle spotters on the beach. The number of visitors who participated in night-time turtle tours during months when the TSP was running (July October) is shown in Table 17. The Public Beach is the northern 3 3/8 miles of beach from Tortuguero river mouth to the limit of Tortuguero National Park; this part of the beach is divided into three sections for the TSP. The Park Beach is the 1 5/8 miles of beach from the limit of the National Park to mile 5, and is divided into two sections for the TSP. Visitors who participate in tours within the Park section of beach must have a valid National Park entrance ticket. Table 17. Number of visitors participating in turtle tours in 2009 Month Public Beach # visitors Park Beach # visitors Total # visitors x visitors / night July 6,869 4,654 11, August 8,531 4,946 13, September 4,935 1,291 6, October 1 3, , Total 23,369 11,436 34, Data from ACTo 1 No data recorded for 6, 7 and 18 October 2 Calculated from 1 July 31 October Almost 35,000 visitors participated in turtle tours between 1 July and 31 October 2009 (See Table 17); this was 12,705 fewer than in As in previous years, the Public Beach section was more popular with guides than the Park Beach; more than twice as many people took tours in the three northernmost sections of TSP (23,369 compared to 11,436 visitors, respectively). Peak visitation was in August, when 13,477 visitors went on tours, with an average of 435 visitors per night during that month (See Table 17). For 2009 an average of 283 visitors per night participated in turtle tours during the TSP. The maximum number of tourists to participate in turtles tours on a single night was 647 on 11 August; the maximum number of people per section for a two hour tour, recorded on 7 August, was 70 (Data from ACTo). Following the successful implementation of the alternative funding scheme for the TSP in 2007, during which all the expenses of the TSP were funded from the sale of information brochures that were offered to all tourists to Tortuguero, the TSP committee continued the system in Throughout the four months of the TSP (1 July - 31 October) 34,805 tourists participated in turtle tours; of these 22,066 purchased a brochure, or 63.4% of all visitors (Data from ACTo). The percentage of visitors purchasing a brochure was almost the same as in 2008 (63.7%). Local guides were still reluctant to purchase the brochure for their tourists, and the larger hotels were the primary supporters of the TSP. The brochures and the sale of t-shirts to the end of December 2009 raised a total of $92,421. This was not enough to cover the expenditure for the TSP during the entire season ($97,248), which included all the salaries and benefits of the spotters, the purchase and maintenance of equipment, production of 36

40 merchandise, all administration charges and two donations to the community and Tortuguero National Park; however, there was a surplus of funds from 2008 which covered the remainder. The two donations were towards the costs of a new roof for the community basketball/meeting salon in the centre of the village ($31,177), and the construction of a roof for one of the administration buildings at the park ranger station in Tortuguero ($13,556). At the beginning of 2009, the TSP committee decided to use the excess funds from 2008 to construct a new tourist waiting area in sector 2, and to make alterations and renovations to the airport building (owned by CCC) for use as the waiting area in sector 1. Additional surplus funds were used to produce new brochures and t-shirts prior to the 2009 season, and to provide a cash buffer to cover program start-up expenses for the new season Hatchling disorientation On only one occasion from June - November was evidence of disorientated hatchlings recorded during monitoring activities (See Table 18). Researchers conducting a night patrol encountered disorientated green turtle hatchlings trying to make their way to the sea; all of the 18 hatchlings found alive successfully made it to the ocean. Table 18. Hatchling disorientation observed during the 2009 Green Turtle Program Date Species Mile Possible cause of disorientation No. hatchlings disorientated No. hatchlings found dead No. hatchlings found alive 20 Sep Cm 3 Icaco Cabina Cm = Green turtle 3.9 Environmental Education and Community Outreach Activities Environmental Education Program Several environmental education activities (See Table 19) were organized by the OEC and RAs during the 2009 Green Turtle Program, for students at the Tortuguero school and high school, and the San Francisco school. In addition, events were also held in Barra del Colorado, Parismina and Moin; these are coastal communities close to Tortuguero. Appendix 3 includes photographs of some of the environmental education activities conducted. Table 19. Summary of environmental education activities conducted during the 2009 Green Turtle Program Date Description of activity Objectives Student Group 28 July Creation of educational posters to display in Tortuguero village. Distribution of energy-saving light bulbs to community members. To teach students about the benefits of saving electricity and helping to save the environment. To raise awareness in the community about the benefits of using energy-saving bulbs. Tortuguero High School and student participants from Harker Group. 37

41 Table 19. Continued Date Description of activity Objectives Student Group 5 Aug 28 Oct August, September, October September, October Creation of informative posters for tourists to Tortuguero National Park. Distribution of posters to hotels and cabinas in Tortuguero. Treasure hunt in which groups of students had to perform several different tasks, each related to a different species of sea turtle found in Costa Rica. For each task successfully completed they received a piece of the treasure map. Informative theatre play entitled Joba and the turtles in trouble. Weekly cinema for children from Tortuguero community. To raise awareness among visitors to Tortuguero about the rules of Tortuguero National Park during the sea turtle nesting season. To teach the students about the different turtle species found in Costa Rica. To teach the biology and species characteristics of all sea turtles that nest in Costa Rica, and the threats that each species faces. Provide a location where children could watch ageappropriate films in a supervised environment. Allow interaction between RAs and members of the community. Student participants from UNC Group. 2 nd 6 th grades students at Tortuguero school. Students at Tortuguero, San Francisco, Barra del Colorado, Parismina and Moin schools. Children from Tortuguero CCC was also invited to participate in the 2 nd Tortufest the 3 5 September; a cultural and music festival organized by members of Tortuguero community. The OEC and RAs developed a series of different events for the three day festival: Kite workshop approximately 50 children participated over the course of the three days to create simple kites that were displayed for the duration of the festival. Local artisans assisted the RAs in the production of the kites. Informative trail entitled Discover sea turtles a series of posters were created for the public with information and photographs about sea turtle biology, species characteristics of the turtles nesting in Costa Rica and a summary of the 50 years of research and conservation of CCC in Tortuguero. At the end of the trail was a tree of ideas where people were invited to write their thoughts about CCC, the beach, sea turtles and the environment. RAs presented the play Joba and the turtles in trouble the play, designed to give information about the different sea turtle species nesting in Costa Rica, was presented to community members and tourists. 38

42 Face painting RAs conducted a face painting activity with children from the community. Cinema films were presented for children from the community; this activity became a weekly event throughout September and October. On 8 September the OEC was invited to participate in the 1 st Scientific Fair organized by Tortuguero High School; information panels produced for the Tortufest were displayed and the OEC was asked to judge the student poster competition. The OEC, FC and RAs held an activity at Tortuguero School on 12 September to celebrate Children s Day; approximately 30 children from the community took part in the event. To celebrate Costa Rican Independence Day on 14 September, the OEC, FC and RAs were invited to take part in the lantern procession organized by Tortuguero High School. From 29 October to 1 November the OEC, FC and RAs organized a series of events as part of the celebration of the 34 th anniversary of Tortuguero National Park: Photograph exhibition Presentation of photographs taken during the kite workshop as part of Tortufest in September. Drawing competition Children from the community took part in a competition to create a design for Ecobags. Cinema films were presented for children from the community; this activity became a weekly event throughout September and October. Boat parade CCC boats were decorated by the OEC, FC and RAs to represent the marine environment and the OEC, FC and RAs created costumes to wear during the annual boat parade along the Tortuguero river. Mask parade The OEC, FC and RAs produced paper mâche masks with students from the Tortuguero High School for the parade Junior Research Assistant Program The Junior Research Assistant Program (JRAP) ran for a second year in 2009; from September thru October. Fifteen students, some of them returning for a second year in the program, received theoretical and practical classes which included basic sea turtle biology, principal threats at the national and international level, and an introduction to turtle conservation initiatives; of these six completed all the necessary assignments and received a certificate and specially designed t-shirt. As part of the JRAP activities, CCC was invited to participate in the 8 th Student Sea Turtle Symposium on 19 th September, This annual symposium is organized by Ecology Project International, an organization that coordinates environmental education trips for high schools students in Costa Rica and other countries. The OEC, Scientific Director, one of the RAs and a group of seven Junior RAs (all students from Tortuguero High School) participated in the symposium. They had the opportunity to share their sea turtle experiences with other high school students from the region and presented posters showing the two research projects conducted by the Junior RAs in 2008: How has the straight carapace length of green turtles (Chelonia mydas) nesting at Tortuguero beach changed over the last 10 years? Does the lunar phase affect green turtle (Chelonia mydas) nesting behavior at Tortuguero beach? 39

43 3.9.2 Community Outreach Activities Veterinary Clinic Following the success of the first spay/neuter clinic program during 2008, two further clinics were conducted during 2009, one during the Leatherback Program, the other September. CCC was involved in the coordination prior to the clinic, and also provided logistical support during the three days that the veterinarians were working in Tortuguero. In June the results of the 2008 veterinary clinics were presented to the tour guides of Tortuguero; their support was requested for the project, in the form of a financial donation towards materials, from the voluntary contributions made by guides to a community fund during the turtle season. Prior to the clinic in September RAs assisted TNP staff to conduct educational talks at the schools and to members of the communities of Tortuguero and San Francisco; they discussed the importance of castration for the health of domestic animals, and gave details about the clinic. Veterinarians from the Humane Association for Animal Protection in Costa Rica (AHPPA) attended the clinic on September; they spent 1 ½ days in Tortuguero and one day in San Francisco. In Tortuguero 42 dogs/cats were castrated and 72 animals received parasite medication; in San Francisco, 17 animals were castrated and 62 were given parasite medication. These figures bring the total for 2008 and 2009 to 257 castrations. CCC provided board and lodging to the vets during the clinic. In addition, the FRC and RAs provided logistical support to the vets in Tortuguero as needed Independent Research Projects The independent research project conducted by Peter Kowalski during the 2009 Green Turtle Program was completed successfully and provided some interesting data about the impacts of tourism on turtle nesting behavior, depredation and hatching success Impact of tourist presence on the nesting behavior, survivorship and hatching success of green turtles The student (Peter Kowalski) worked in close liaison with the Turtle Spotter Program to encounter turtles with tourists present during the nesting process; all of the spotters and guides were very helpful during the data collection phase of the study. The 2009 Green Turtle Program RAs assisted in the collection of data for the project; to ensure that the sample size was sufficiently large enough to make valid scientific analyses. In 2009, a total of 55 females were included in the study. Of these, 42 turtles were timed during the nesting process and the nest was marked to determine survivorship and hatching and emerging success. The other 13 turtles were only timed. Due to the fact that the nest marking process could have affected the behavior of the turtle (as it is conducted while she is laying her eggs); it was decided to not combine these data with those from females whose nests had not been marked. Therefore, data from 11 of the 13 females whose nests were not marked were combined with data collected in 2008 (n = 85). Two of the 2009 females were excluded from analysis as they abandoned the nest after laying only a few eggs (and continued to lay more eggs on their return to the sea) and four were excluded from 2008 as they did not complete all of the phases of the nesting process. This gave a total of 92 females for which timings of each phase of the nesting process were conducted, and 42 females who were timed 40

44 and had their nests marked. Unfortunately, 14 of the marked nests could not be found during the excavation, and so analyses comparing survivorship, hatching and emerging success to the number of tourists present included data from only 28 females. The number of people (including researchers, spotters, guides and tourists) observing a single turtle (2008/2009) ranged from Individual turtles were assigned to one of three categories depending on the number of people present during the nesting process; No impact turtles that were observed only by 1-2 researchers, Low impact turtles observed by 3-40 people or High impact turtles observed by more than 40 people. For the analysis data from 2008 were also incorporated to give a larger sample size for analysis. In total, data from 92 females were analyzed; 33 No impact, 28 Low impact and 31 High impact. Table 20 shows the mean duration of the different phases of the nesting process calculated for turtles in each of the three impact categories; in 2009, oviposition was not timed, only covering and camouflaging the nest site. Table 20. Duration of different phases of the nesting process for turtles subject to different levels of tourism impact data from 2008 and 2009 Impact Category N Covering Camouflaging x min ± SD Range x min ± SD Range No impact ± ± Low impact ± ± High impact ± ± Total ± ± From Table 20 it can seen that there was considerable individual variation in the time spent on the different phases of the nesting process; covering ranged from minutes and disguising the nest site ranged from minutes. As in 2008, no significant difference was observed between the three different impact categories for the time spent in covering ( No impact / Low impact : F = 3.55, p = 0.064; Low impact / High impact : F = 1.4, p = 0.242); No impact / High impact : F = 0.5, p = 0.483). However, there was a significant difference observed for the time spent camouflaging the nest site between the No impact and the two categories with tourists ( No impact / Low impact : F = 4.55, p = <0.05; No impact / High impact : F = 9.29, p = <0.05); no difference was detected between Low impact and High impact groups (F = 0.90, p =0.346). No difference in hatching success was determined between the three different categories. Depredation of nests was used as a variable by which to investigated survivorship; in order to determine whether turtles which spend a shorter amount of time camouflaging nests will experience higher levels of depredation, the median time for the entire range of green turtle camouflage time was determined (range = minutes, median = minutes). Durations which were below the median were classified as Short camouflage time and durations which were above the median were classified as Long camouflage time. The sample sizes for these groups were too low to determine statistical significance (n = 28). However, the percentage of nests depredated in the Short camouflage group (66.7%) was twice that observed for nests Long camouflage group (33.3%). This trend was also evident in the number of depredated eggs found in the nest at excavation; the data exhibit a weak (non-significant) negative correlation between the camouflage time and the number of depredated eggs in a nest (R 2 = ). 41

45 3.11 Satellite Tracking Project Both satellite transmitters were successfully deployed in July, The first turtle was encountered nesting close to the station in mile 2 4/8 on 20 July; she measured 107.3cm CCLmin and 97.6cm SCLmax. The transmitter was attached the following morning and she was given the name Chica in honour of Chica Maynard, a long-term member of the CCC Board of Directors who passed away in 2009 (See Appendix 4 for photographs of the transmitter attachment process and release). Her transmitter was sponsored by CCC and her cause was the effect of sea level rise and climate change on sea turtles and their habitats. Following her release Chica stayed close to the nesting beach for several weeks; she was tracked south for a few miles, but she remained within the marine limits of Tortuguero National Park. She was observed nesting again at mile 4 1/8 on 10 August; researchers checked the condition of the transmitter and reported no obvious problems. She was not encountered again on the beach and at the start of September was tracked heading north away from the nesting beach. Chica was tracked for 134 days, during which time she swam a total of 391 miles (629 km); when her transmitter stopped sending signals in October, 2009 she was located in shallow waters off the coast of Nicaragua, presumably in sea grass habitat (See migration map in Appendix 3). The second turtle was encountered on 21 July; she nested just south of the CCC field station in mile 2 6/8; she measured 102.5cm CCLmin and was given the name Aurora. She was fitted with a GPS satellite transmitter sponsored by Shark Reef Aquarium and her cause was the impact of continued consumption of sea turtle meat. Following her release, Aurora was also tracked for several weeks in near-shore habitat close to Tortuguero, although she moved much further south than Chica, reaching almost as far south as Limon before she returned to within Tortuguero National Park marine boundaries. She was not encountered again on the nesting beach, and at the end of August began her migration north; she was tracked to the same area as Chica, a known green turtle feeding area. Aurora traveled 570 miles (916km) before her transmitter stopped sending signals in October 2009 (See migration map in Appendix 3). 4. Discussion 4.1 Preparations The training and orientation program given to the RAs by the FRC is essential for them to learn the monitoring protocol in detail, and to give them the opportunity to practice various important skills, such as tagging, carapace measurements and nest marking. Even for RAs with previous experience working with sea turtles these theoretical and practical sessions ensure that everyone collects data according to the CCC protocol. In future years care should be taken to make sure that all RAs receive sufficient practice in tagging during the training sessions, and adequate supervision throughout the program to detect anyone who might be having issues tagging. The FRC should work with all the RAs regularly to evaluate the data collection of the RAs, and bring to their attention any errors that are being made at the soonest opportunity to ensure a high level of accuracy in the data being collected. The new orientation program, incorporated in 2008 helps to provide the RAs with a more balanced view of Tortuguero, the National Park and the community. Also, the organization of regular group activities, designed to develop good dynamics amongst the RAs, helped to maintain a good relationship in the group. Fortunately the majority of the beach markers placed at the start of the 2009 Leatherback Program were still in excellent condition at the start of the 2009 Green Turtle Program; the FRC and RAs were limited to replacing an occasional missing marker and repainting those still in place. This activity, 42

46 though somewhat time consuming, is important as it provides the opportunity to teach the RAs the need to familiarize themselves with the beach and the markers to facilitate the night patrols. For future years it might be worth investigating the possibility of using reflective paint or tape for the beach markers to assist with finding them at night. 4.2 Track Surveys The surveyor who was contracted in 2008 continued to conduct track surveys in The FRC was responsible for collecting the completed data sheets the day after a track survey; this protocol should definitely be continued in future years Green Turtles Green turtle nesting was observed from April to December, with one obvious peak in nesting in September; over 2,000 nests were observed in a single night on 13 September (See Figure 1). Almost 110,000 green turtle nests were estimated to have been laid during the 2009 season, which was slightly higher than in The overall positive trend in green turtle nesting observed since the mid s, when surveys of the entire nesting beach began, continues (See Figure 2); a 94% increase in green turtle nesting per year has been recorded since In 2009 green turtle nesting between the Tortuguero river mouth and the mile 5 marker represented 14.7% of all nesting for this species between the river mouth and Jalova lagoon; this is slightly less than the percentage observed in The overall spatial distribution along the beach was similar to that observed in recent years, with a distinct increase in nesting noted between miles 4 13 (See Figure 3). Peak nesting occurs within the centre of the beach; in 2009, mile 10 had the highest number of nests recorded. The daily track surveys conducted by the FRC and RAs from June - November between the Tortuguero river mouth and the mile 5 marker require considerable effort but provide invaluable data relating to spatial and temporal nest distribution, level of illegal take of nests and females, and dog predation. While they were originally initiated in 2004 as a means of evaluating the effectiveness of the Turtle Spotter Program in minimizing negative impacts of tourism on turtles, they are now an integral part of the monitoring protocol for the Green Turtle Program. Over 17,000 green turtle nests were laid in the first five miles of the beach, and more than 14,000 false crawls were recorded; successful nesting was recorded in 54.6% of emergences. Of these, nesting within the limits of Tortuguero National Park accounted for 55% of all nests (for the first five miles), which was the same as in There seemed to be more nesting towards the river mouth (from mile - 1/8 to 7/8), with few nests recorded in front of the village (mile 2 7/8 3 3/8). Temporal distribution of nesting observed from the daily track surveys was similar to that for the weekly surveys, with the peak of the green turtle season occurring at the end of August to mid- September (See Figure 5b). On only three occasions during the weekly track surveys in 2009 was the illegal take of turtles or nests reported. However, during one survey 160 nests were recorded as poached; all of the nests within certain miles of the beach, within the limits of Tortuguero National Park. Such intense poaching suggests highly organized groups are targeting the beach, and it remains high priority to share all information regarding illegal take of nests and or nesting females with the authorities. The harpooning of turtles in near-shore waters close to the nesting beach appears to have become more prevalent during Evidence of this activity (photographs of a pair of mating turtles being harpooned), 43

47 which targets both male and female turtles, was sent to both MINAET and the Costa Rican Coast Guard to highlight the problem and also to request a more integrated protection strategy. As a consequence of this letter CCC signed a memorandum of understanding with the Coast Guard to assist in their turtle protection efforts; a joint patrol of near-shore waters within Tortuguero National Park was conducted by the Coast Guard and MINAET personnel during the 2009 Green Turtle Program, with CCC providing financial assistance to cover gasoline costs. Such operatives are vital to deter would-be poachers/fishers by the presence of the relevant enforcement authorities. In future years CCC will continue to search for funding to support such protection initiatives. Poaching levels were lower in 2009 than those recorded in 2008, however, during the daily surveys of the northernmost five miles of beach poaching of either nests or turtles was still observed on over 40% of surveys. A total of 133 green turtle nests, plus 14 females were taken during the 2009 Green Turtle Program (See Figure 6); a similar pattern of illegal take was observed in 2009, with many nests taken close to the river mouth (mile -2/8 2/8), and around the limit to Tortuguero National Park (mile 3 3/8). Data were shared with MINAET staff, and it is recommended that in future programs a weekly report of all illegal activity recorded during by CCC researchers during daily and weekly track surveys be sent to the Tortuguero National Park staff, to allow them to focus limited resources and personnel in problematic sections of the beach. Jaguars continued to predate turtles in 2009; weekly track surveys recorded 37 females killed within the park from June November. This is a minimum number as the surveyor only recorded freshly killed turtles from the previous night, and did not include all those killed since the prior survey. As observed previously the percentage of females taken by jaguars is insignificant and they do not pose a grave threat to the nesting population; however, it appears that jaguar predation is becoming more consistent, especially during the main green turtle nesting season, with freshly killed turtles recorded on all but four surveys from 14 June to 22 November; with up to five individuals being killed in a single night on occasions. Further investigation of jaguar predation would help develop a model of turtle-jaguar interaction within Tortuguero National Park Hawksbill turtles During the weekly track surveys of the entire nesting beach just six hawksbill nests were observed in 2009; however, the daily track surveys of the northern five miles recorded 18 nests and 11 false crawls. Unfortunately the low density of hawksbill nesting is not easily detected by weekly surveys, and so it is useful to have the data from the daily surveys with which to compare. Also, the smaller hawksbill tracks could easily be erased by the numerous green turtle tracks, especially in areas of the beach with high green turtle nesting density, such as the middle of the park, for example. It is important, therefore, to view the number of hawksbill nests as a minimum, with the assumption that some tracks are not reported due to the presence of large numbers of green turtle tracks. From the surveys it would appear that hawksbill nesting has shown a slight increase in the last few years, which is very encouraging for this critically endangered species. Temporal distribution of hawksbill nesting seemed to show a similar pattern to 2008, with increased activity recorded in July; on two nights in July two hawksbill nests were recorded. The data from the daily track surveys are important to provide more detailed information to corroborate the weekly surveys Leatherback turtles A comprehensive discussion of leatherback nesting at Tortuguero in 2009 can be found in the 2009 Leatherback Program Report. Leatherback nesting density still remains low at Tortuguero, though the 44

48 estimate for 2009 was slightly higher than The development of the regional leatherback data base, and open communication between nesting beach projects along the Caribbean coast of Costa Rica and Panama will assist with protection and conservation efforts aimed at this critically endangered species. 4.3 Tagging of Nesting Sea Turtles Green turtles The goal of 1,000 newly tagged green turtles was successfully achieved in October Whilst tagging efforts were obviously focused on the peak of the season, to ensure that 1,000 new females were tagged, new turtles were also tagged throughout October, Additional tags were purchased to ensure that there were sufficient to continued tagging efforts until night patrols ended on 30 October. In future years this practice will be repeated, to allow information about newly tagged turtles encountered later in the season to be collected. Almost one third of all individual females observed in 2009 were previously tagged (n = 594); this was higher than the number observed in As always, these encounters with previously tagged females are important for they allow the estimation of between season tag loss, annual survival probabilities and also highlight any turtles that are from other research projects, either on nesting beaches or foraging grounds. There were a considerable number of females that had originally been tagged more than 10 years previously; of the 594 females 82 (13.6%) were first seen in Tortuguero more than a decade earlier. Furthermore, nine females were first tagged over 20 years previously. The turtle with the longest nesting record observed in 2009 was a female first encountered in 1982 (27 years ago). It is good to see that there are a considerable number of older females that return to nest each year, and that there are still plenty of new (untagged) females being encountered; which suggests a balance of different age classes within the Tortuguero nesting population. Each year several green turtles are encountered with tags from other nesting beach projects, and 2009 was no exception. There were 32 females with tags from Cano Palma (the research project just north of the Tortuguero river mouth), Mondonguillo, Parismina and Pacuare. As other monitoring projects become established along the Caribbean coast of Costa Rica the information about the frequency with which green turtles move between different beaches will become more widely available. It was also very interesting to encounter green turtles with tags from locations outside of Costa Rica; one from Belize and one from Mexico. Every effort is being made to contact sea turtle researchers working in Mexico to determine when this female was originally tagged. It is presumed that she was encountered during in-water tagging projects on feeding grounds, and not on nesting beaches. The turtle from Belize is especially interesting as she was one of only five turtles tagged as part of the Save a Sea Turtle Program, and the only turtle to have been encountered following her release. Researchers in Belize were extremely excited to learn this turtle had been observed while nesting at Tortuguero. Such encounters highlight the significance of the work conducted by the Archie Carr Centre for Sea Turtle Research, based at the University of Florida in Gainesville. They are responsible for the coordination of tag returns from turtle projects working within the Caribbean, and facilitate communication between researchers in various countries when they encounter tags from different projects. 45

49 4.3.2 Hawksbill turtles Disappointingly very few hawksbill turtles were encountered in 2009 (n = 6); this was less than half the number observed in 2008 (n = 13). Of the few females that were seen, however, it was encouraging to encounter individuals that were tagged at Tortuguero several years ago (2001 and 2003); there were also two females that were first tagged by Caño Palma researchers working north of the Tortuguero river mouth. Given the very low nesting density of this species at Tortuguero it is important that all RAs realize the importance of every encounter with a nesting hawksbill during night patrols as they provide very valuable information on the species. The protocol to not show hawksbill turtles to tour groups (first implemented in 2008 following a request by the Scientific Director to the Turtle Spotter Program committee) was continued in Priority was given to CCC research groups for this species Leatherback turtles The 2009 Leatherback Program Report includes a detailed review of the tagging of leatherback turtles at Tortuguero in Once again, however, a number of leatherback turtles (n = 5) were encountered during night patrols during the first month of the 2009 Green Turtle Program; the last nesting female was observed on 15 July. None of these females had been encountered during the 2009 Leatherback Program. 4.4 Biometric Data Collection Green turtles The overall mean curved carapace length (CCLmin) was 105.4cm and the mean straight carapace length (SCLmax) was 98.7cm. These measurements are consistent with those obtained from the Tortuguero green turtle population in previous seasons, and they also show a typical range from very small to very large individuals ( cm CCLmin; cm SCLmax). In addition, the mean clutch size of eggs was very similar to that determined in other years. Research Assistants and volunteer participants showed the same degree of precision for CCLmin measurements, but RAs were slightly more precise when taking SCLmax measurements. This would indicate that the training provided by the FCs at the start of the program was effective, although care should be taken to ensure that the volunteer participants are adequately supervised during the collection of carapace length data. There was, however, considerable variability in the measurements taken of the same female when she was observed on more than one occasion, and so care should be taken during training sessions, with RAs and volunteer participants, to ensure that everyone is measuring the carapace in the same manner, using the same start and end points. CCLmin and SCLmax measurements were taken with the same degree of precision, and it is suggested that both measurements continue to be taken for a sample of females nesting at Tortuguero Hawksbill turtles Carapace measurements obtained for hawksbill turtles during the 2009 Green Turtle Program were within the range observed in previous years. CCLmin measurements were less precise for hawksbills than for green turtles, but the opposite was true for SCLmax measurements. The mean clutch size for hawksbills was similar to that determined in other years (165 eggs), and is well within the known range 46

50 for this species in the Caribbean region Leatherback turtles The 2009 Leatherback Program Report summarizes biometric data collected from leatherback turtles nesting in Tortuguero in 2009 from March to June. For females observed during the 2009 Green Turtle Program, the mean carapace length (CCLmin) was 150.4cm. Only one clutch of eggs was counted, and it contained 76 eggs, plus 12 yolkless eggs. 4.5 Fibropapilloma Assessment Of the sample of green turtle females specifically examined for the presence of fibropapilloma tumors in 2009 (n = 72) none were reported to have tumors present. This is unusual, as there is typically a very small percentage of females that do have the disease; however, the number of turtles checked was lower than in previous years, and this could reflect the fact that no affected individuals were encountered. It is important that the subset of females checked for this disease remains relatively constant each year, to ensure that any changes in the prevalence of this disease within the Tortuguero green turtle population can be identified. Fibropapilloma is definitely present in the green turtle population nesting in Tortuguero; in 2009 one female was observed with a small tumor on her left front flipper. It is important to continue to monitor the presence of this disease in future programs, and to pay particular attention to the training of RAs in its identification, so that any real increase in its prevalence can be monitored immediately. With reference to a recommendation from 2008, permission to photograph turtles encountered during night patrols that have injuries or anomalies (including fibropapilloma tumors) was included in the application for the 2009 research permit. 4.6 Determination of Nest Survivorship and Hatching Success Green turtles A total of 173 green turtle nests were marked during the 2009 Green Turtle Program, which is more than were marked in Of these 110 were inspected daily during the incubation period, and excavated to determine hatching and emerging success. The other 63 nests were eliminated from the analysis of survivorship and hatching success for a variety of reason; including those that could not be found at excavation, those that lost all three flagging tapes, those that still contained hatchlings at the end of the program, or for another reason could not be excavated. It was discouraging that 34 (19.6%) nests could not be found on excavation, and so their fate or hatching success could not be determined. A proportion of these nests could potentially have been poached within a couple of days of being laid, or were disturbed during the incubation period by another nesting turtle; and that these situations were not detected by researchers during the daily nest check. It is important to stress to the RAs during their training sessions the need to carefully monitor all of the marked nests every day during the incubation period, and to be extra vigilant of new nests, which are subject to poaching pressure during the first couple of days. Nests close to the predicted emerging date should also be carefully inspected for signs of hatching (depressions or hatchling tracks); in 2009 the incubation period could only be determined for one nest for which hatching was observed. Although depressions and hatchling tracks can be quickly eliminated by heavy rain or strong winds it should be possible to detect evidence of hatching if RAs are more conscientious. As in previous years the majority of nests (77.3%), remained undisturbed during the incubation period and hatched successfully. Of those nests that were disturbed only two were poached; which was much 47

51 fewer than the number recorded in There were also only four nests that were partly depredated, which hopefully is a reflection of a reduction in the number of dogs in the village and/or better control by dog owners during the turtle nesting season. In future programs it would be interesting to monitor the level of dog predation, in both fresh nests and also older nests that could be due to hatch and so have hatchlings within the egg chamber. Overall hatching and emerging success of marked nests was lower in 2009 than in 2008, 77.6% and 73.2%, respectively; although they are within the range observed for green turtles at Tortuguero previously. For undisturbed nests (n = 85) emerging and hatching success were high, 86.5% and 84.8%, respectively. The estimation of overall hatching and emerging success were affected by nests that hatched successfully but did not emerge; large numbers of dead hatchlings were found within the egg chamber at excavation suggesting possible inundation after they emerged from the egg. Also by nests that were partly depredated or disturbed by another nesting female. As previously, very few deformed embryos were recorded during excavations. The same pattern of nest site selection was observed in 2009 as in previous years, with the majority of green turtles choosing to lay their eggs in the border zone; these nests would be partially shaded during the day and so less likely to be subject to extremely high temperatures that could result in embryonic death Hawksbill turtles Only two hawksbill nests were marked during the 2009 Green Turtle Program. Both nests were undisturbed and hatching and emerging success were high (84.7%), as has been observed previously at Tortuguero for this species. It is hoped that the policy to not show hawksbill turtles to tour groups will allow CCC personnel priority access to this species, and that in future more nests will be marked and followed during the incubation period, to gain a further insight into the survivorship and hatching success of this critically endangered species at Tortuguero Leatherback turtles A discussion of leatherback nest survivorship and hatching success in Tortuguero during 2009 can be found in the 2009 Leatherback Program Report. 4.7 Physical Data Collection Rainfall The pattern of precipitation observed in 2009 was similar to that observed in other years, with very high rainfall in July, August and November. Surprisingly, May and June were very dry months; typically rainfall increases in June. September was very dry and then rainfall increased in October and November was the wettest month with over 900mm of rain collected during the month. The physical data collected by CCC at Tortuguero over the last ten years are important as they provide a baseline of information against which any future changes that may arise as a result of global climate change might be compared. It is, therefore, important to maintain the daily collection of rainfall and air temperature as part of the standard monitoring protocol. 48

52 4.7.2 Air temperature The air temperature data recorded during 2009 somewhat reflect the pattern of rainfall observed during the Green Turtle Program; July, August and November (with high rainfall) were the cooler months, while September had the higher temperatures recorded (and was also the driest month). The range of temperatures observed (19-31 C) was consistent with those from other seasons in Tortuguero Sand temperature Unfortunately the loss of the data loggers from the Border and Open zones during the 2009 Green Turtle Program was not detected until the end of the season when the data loggers are typically retrieved to download the stored information. It is assumed that the data loggers were possibly disturbed by a nesting turtle, which uncovered the cord used to secure them; it is possible that someone then encountered the data logger containers and removed them from the beach, either knowingly or from simple curiosity. The data loggers cannot be used without the correct computer software, and so are of no use to anyone other than CCC; however, occasionally research equipment, including data loggers has been taken intentionally in the past. In future, it might be worthwhile downloading the information from the data loggers each month to ensure that they are in the correct locations and have not been disturbed, either by natural causes or people. From the data loggers that were present during the 2009 Green Turtle Program; those in the Vegetation zone at depths of 50cm and 70cm, the data indicated that sand temperature ranged from C. As has been observed in other years, the Vegetation zone was not subject to extreme temperature changes and remained relatively constant throughout the year, despite large differences in the level of rainfall experienced from June to November. Eggs in nests laid in the vegetation zone will like be subject to temperatures before the recorded pivotal temperature for green turtles, and so it is assumed that the majority of hatchlings produced will be male. However, the percentage of green turtle nests laid in the vegetation zone is low; only 13.6% of all marked nests were deposited in this zone of the beach. In future programs it is important to continue to monitor sand temperatures at Tortuguero, as for the other physical data that are recorded each day, this information will allow the detection of any changes to the nesting habitat environment that could be a result of global climate change. 4.8 Collection of Human Impact Data Visitors to CCC Visitors Centre 2009 was the third year in succession in which there was a decline in the number of people entering the CCC Visitors Centre; the decrease in visitation, however, was much greater than that previously observed, with almost 2,000 fewer tourists received in 2009 than in This decline in tourism reflected the situation of the global economy, with fewer people choosing to take international vacations; for the majority of tourists to Tortuguero are from countries other than Costa Rica. The situation recorded at the CCC Visitors Centre was also observed throughout the community of Tortuguero in 2009, with some of the larger lodges and hotels forced to close for periods of time, or run with minimal staff to reduce expenses. It is hoped that in future years the global economy will improve and so visitation will increase in Visitors to Tortuguero National Park Data available from ACTo for 2009 only include visitation figures from January to November; 49

53 however, from these data it would appear that tourist visitation to TNP in 2009 declined for the first time in at least 10 years (See Table 15), with over 20,000 fewer tourists paying the park entrance fee. However, the discovery in 2009 that there had been a change made to the way in which visitation to the park was recorded in 2006, without informing CCC or other institutions that might have subsequently used the data, prompted CCC to write an official letter of complaint to ACTo. In the opinion of CCC, tourist visitation data have been recorded erroneously by park staff since 2006; they have included guides and boat captains in the figures for national visitors, when obviously these individuals are leading tour groups and so are not, technically speaking, tourists. Considering the number of tours that are conducted within TNP each year, including the canals, trails and the beach, and the number of guides that repeatedly enter the Park over the course of the season, the potential for error in the number of national tourists could reach into the thousands. For example; if one tour guide enters the National Park to give a turtle tour five days a week during the peak turtle tourism months of July October, that one person would be counted as 80 individuals. Given that there are over 100 registered turtle tour guides, then there could be over 8,000 tourists counted as having entered the park. From Table 15 it is possible to see the dramatic increase in national tourists recorded between 2005 and 2006, when the change in the data collection method occurred; from 9,292 to 21,257, respectively. Furthermore, the value for the number of national tourists is further compounded by the fact that tourists from Central American countries are also included as national tourists; due to the fact that they pay the same reduced park entrance fee. When these errors were made known to CCC they requested the true national tourist values from ACTo staff; however, it appears that the data are not readily available in digital format to recalculate the value, and so to date no new data have been received. What is apparent is that there was a genuine decline in the number of tourists visiting TNP in 2009; reflecting the decline in visitation observed by CCC to the Visitors Centre, and the overall reduced level of tourism to the area as a result of the global economy. Revenue to TNP was undoubtedly much reduced in 2009, and there was an evident lack of personnel during the Green Turtle Program. No park guards were observed during monitoring activities (either during the day or night), although it is possible that the limited resources were focused on more problematic areas within the Park (ie. where poaching pressures on turtles and nests are higher), and so these initiatives would not have been witnessed by researchers. CCC will continue to work with MINAET personnel to provide relevant information about illegal take of turtles and/or nests, to assist in the focused protection efforts. In addition, agreements such as that signed with the Coast Guard, will be implemented with MINAET to allow CCC to provide funding for increased protection initiatives aimed at protecting turtles Capacity of hotels and cabinas The capacity of hotels and cabinas in Tortuguero fluctuates between years, as establishments increase the number of rooms or are closed for refurbishment for extended periods. In 2009 there were few hotels that constructed new rooms; while room capacity did increase slightly (to 689 rooms) the number of beds available to tourists actually decreased slightly (to 1,456 beds). During 2009 several of the larger hotels actually closed due to unsustainable occupancy levels, and many others cut staffing levels due to reduced numbers of visitors. CCC will continue to monitor the growth of tourism in the area to ensure that future development does not impact negatively on the fragile ecosystems and endangered species that exist in the region Turtle tours Turtles are one of the main reasons why many visitors come to Tortuguero; thousands of people are attracted to TNP each year with the expectation of witnessing a turtle nesting on the beach. In 2009 the reduction in the number of visitors to TNP was, therefore, reflected by a decline in the number of 50

54 tourists who paid to go on a turtle tour. During the official green turtle season (July October) 34,805 people paid to go on turtle tours in 2008; a reduction of almost 13,000 from Tourism peaked on 11 September when 647 people participated in tours on one night. While the Turtle Spotter Program (TSP) is designed to coordinate the tour groups, and definitely limits the impacts that such numbers of people are having on the nesting turtles, there were definitely occasions in 2009 when there appeared to be no control of the groups around nesting turtles. There was no defined limit to the number of people that were permitted around a single female and, as can be send from the results of the study to investigate the effects of tourist presence on turtle nesting behavior (See section and ), more than 60 people were allowed to be on the beach to view just one female. Park guards were not encountered conducting checks of tour guides or ensuring that the rules of the Park were being observed, and at times it was difficult to conduct monitoring activities due to the presence of many tour groups. It should be a priority of the TSP committee to address the issue of carrying capacity and MINAET (who ultimately control tourist activities within TNP) need to set a limit for the maximum number of people that can be permitted to view one turtle. One of the primary objectives of the TSP is to minimize negative impacts of tourism on the nesting population of green turtles on the beach; with no defined limits then the program is potentially failing to achieve this goal. The lack of a designated coordinator for the TSP in 2009 was also evidenced, despite ACTo staff taking on the majority of the responsibilities of the coordinator. This was most obvious in the lack of coordination of the data pertaining to the sale of brochures; in 2008 a daily record of the number of brochures sold was entered by the Coordinator. However, in 2009 this information was not recorded each day, and so it was not possible to determine the support of each of the guides independently, or the hotels; only a much more general description of the brochure sales was possible at the end of the season. In future it would be advantageous for the TSP to contract someone to manage the data regarding the daily brochure sales; funds from these sales cover the TSP expenses and it is vital to have the most detailed and up to date information available for hotel owners and guides who support the program. Although the percentage of tourists who purchased a brochure in 2009 was similar to that for 2008 (63.4% compare to 63.7%, respectively) the reduction in the actual number of tourists participating in turtle tours meant that the revenue raised from the sale of brochures was considerably less than in previous years. In 2009 a total of $87,321 was raised from brochure sales, plus a further $5,100 from t-shirt sales; the total amount raised was not, however, enough to cover the program expenses of $97,248. Fortunately additional funds from 2008 were available to cover the difference. Money generated from the sale of brochures in 2008 was also used to construct an additional tourist waiting area prior to the start of the 2009 program. As was originally perceived when the brochures were introduced, additional money could be made available to the National Park and the community of Tortuguero; in 2009 the TSP funds were donated to TNP, to construct a roof for one of the buildings at the Cuatro Esquinas ranger station, and the community received a donation towards the reconstruction of the community salon which was destroyed in In 2009 additional efforts were made to increase the support of the local guides in the village for the TSP activities by purchasing brochures for their tourists. CCC RAs and turtle spotters manned a small information kiosk in the centre of the village during the afternoons, to talk to guides and tourists about the TSP and encourage them to purchase brochures to help fund the program. These activities seemed to improve the number of local guides who purchased brochures, and also allowed RAs to interact with turtle spotters and guides more frequently, thus developing a good relationship between all stakeholder groups working on the beach at night. 51

55 The TSP committee also discussed the possibility of making the purchase of a brochure mandatory for all tourists participating in turtle tours, to ensure that sufficient funds are generated to cover program expenses and also provide additional money for donations to the National Park and community projects. The legal issues associated with this change from a voluntary fee are currently being explored by MINAET. The TSP is definitely having a positive impact on the turtle population on Tortuguero, and also the community and the National Park; in 2009 substantial donations were made to TNP and the community. However, the coordination of tour groups on the beach continued to be disorganized in 2009, and there is definite urgent need to improve this vital aspect of the program. What is evident is that there is still overall agreement among stakeholder groups that the TSP is the best method to conduct turtle tours in Tortuguero, given the number of tourists that want to observe turtles. It is important that CCC remains an integral part of the TSP committee, and that it continues to provide technical evaluation of the impacts of tourist activities on the nesting populations of turtles at Tortuguero. Further studies on potential negative impacts and an evaluation of the perceptions of tourists to the TSP would be valuable in the future Hatchling disorientation Only one record of hatchling disorientation was witnessed in 2009 although the issue with excessive artificial light visible on the nesting beach remained a problem despite efforts during the 2009 Leatherback Program to work with the Costa Rican Electricity Institute (ICE) to shield public lights in the village. CCC needs to conduct a dedicated campaign in Tortuguero to raise awareness within the community of the problem that lights can cause to nesting turtles and hatchlings. 4.9 Environmental Education and Community Outreach Activities Environmental education program The continued employment of a dedicated coordinator for environmental education and outreach in 2009 helped to strengthen links between CCC and the community of Tortuguero. CCC was invited to participate in the Tortufest cultural activities and the Eco-Caribena festival to celebrate the anniversary of TNP, in addition to community events organized for Independence Day and National Children s Day. During these events the OEC and RAs conducted educational and fun activities with children and adults; raising public awareness about sea turtles in Costa Rica, the threats that different turtle species face and the work of CCC in Tortuguero over the last 50 years. Through the active participation of CCC staff and RAs in these different events, they developed strong links with community members, especially the students of the school and high school. The role of the OEC is an important one for maintaining a good relationship with community leaders in Tortuguero, and also acting as a liaison between CCC, ACTo staff, tour guides and the TSP. Hopefully sufficient funding will remain available for this position in the future. It was also possible to visit several other coastal communities in 2009; Barra del Colorado (north of Tortuguero), Parismina (just south of TNP) and Moin (close to the town of Limon to the south of Tortuguero). CCC was invited to conduct environmental education activities in these different villages, to help raise awareness along the coast of the importance of sea turtles to the region, and to explain the CCC project over the years in Tortuguero. Hopefully such visits will continue in the future, to generate support among the members of other communities for turtle conservation initiatives, and it might even be possible to coordinate visits by students from these other villages to Tortuguero, to participate in the CCC monitoring activities and interact with local students, especially those involved in the Junior Research Assistant Program 52

56 4.9.2 Junior Research Assistant Program In 2009 the Junior Research Assistant Program (JRAP) ran for the second year; allowing the participation of high school students in all aspects of the Green Turtle Program in Tortuguero. As in 2008, many students participated in the talks and the beach patrols, but few completed all of the necessary requirements to complete the course and receive the certificate of participation. Several of the students from 2008 returned in 2009, and there were also many new recruits. Those students who participated in the Student Sea Turtle Symposium had an opportunity to share their experiences with other students from the region; it is hoped that maybe in 2010 a group of students from Tortuguero can visit Pacuare Nature Reserve as part of a planned trip organized by Ecology Project International. Such a visit will allow students from Tortuguero the opportunity to get more practical experience of sea turtle research and conservation efforts on the Caribbean coast of Costa Rica, and hopefully encourage them to continue their association with the CCC project Community outreach activities Veterinary clinic Further veterinary clinics held in Tortuguero and San Francisco during 2009 continued to receive support for the community. In September 59 animals were in June was extremely successful; more than 60 animals were spayed/neutered, bringing the total since the start of the program in 2008 to 257. Obviously the clinics are not an immediate solution to the problem of dog predation of turtle nests on the beach, however, it is hoped that this will provide a long-term answer to the situation, by reducing the number of dogs in the community over time. Also, the education component of the program aims to raise awareness about animal welfare and so hopefully encourage people to take better care of their domestic animals and also feel a sense of responsibility towards them, so that they do not go out on the beach and destroy turtle nests. CCC will remain involved in the coordination of the clinic program, providing logistical support whenever possible Independent Research Projects Data collection for one independent research project was conducted during the 2009 Green Turtle Program, which was a continuation of a study initiated in 2008 to investigate the potential negative effects that tourists could have on green turtle nesting behavior in Tortuguero. One of the suggestions from the research conducted in 2008, where it was observed that females observed by more than 10 people spent less time camouflaging their nest, was to mark nests and follow them during the incubation period to determine whether there were any subsequent effects on the survivorship and/or hatching success of nests that were laid when large numbers of tourists were present. The student in 2009 received full support from the spotters and the tour guides, many of whom were very interested to know the results of the research. The study showed that many turtles were observed by numerous tour groups, with over 60 people recorded with a single female, and also corroborated the finding from 2008 that females observed by large numbers of people will spend significantly less time camouflaging the nest site than if few people are present. Interestingly, this is in complete contrast to the perceived idea of many of the tour guides who say that if a tour group remains with a turtle while she is camouflaging, she will spend longer at the nest site. This highlights the importance of sharing the results of such studies with all the guides, spotters and other interested groups, to dispel any commonly held mistaken beliefs about turtle nesting behavior. Unfortunately the results of the investigation into the effect of tourist presence on the subsequent survivorship and hatching success of the nest were inconclusive as insufficient nests were monitored or excavated to conduct statistical analysis. However, it would appear that there was a higher level of predation in the nests of turtles that were observed by large groups of people (ie. that spent less time 53

57 camouflaging the nest site). It would be very interesting to continue this investigation in future years, to get a much larger sample size to permit statistical analysis. Given that the results from both years suggest that green turtles are altering their behavior when observed by lots of people, CCC recommends to the TSP committee and MINAET that there be a maximum number of people who can observe a single turtle; a proposed limit of 20 people will be suggested for the 2010 season. At present a maximum of 10 people (ie. one tour group) are permitted around the turtle at any time; any other groups present need to remain at an appropriate distance from the turtle and wait their turn to observe the nesting process. Unfortunately problems arise when there are numerous groups waiting for the same turtle, as there is lots of movement and often the guides cannot adequately control their tourists, and hence why the turtle is disturbed. Also, when turtles are retuning to the sea and there are many people present, they tend to crowd around her and can even impede her progress to the sea. By implementing a limit of 20 people this would allow for 10 people to be close to the turtle, while only 10 others are present on the beach; this should ensure greater control of tourists and minimal impact to the turtle. What is very clear from the studies conducted in both 2008 and 2009 is that the TSP is not fulfilling its objective to minimize potential negative impacts of tourist activities on turtles; while it is preventing the tour groups from walking the beach, it is not adequately controlling tourist groups around nesting turtles. Too many people are being allowed to observe the same turtle; the spotters appear to be sending all the groups to one turtle and then spend their time coordinating the groups around the turtle, rather than sending a few people to the first turtle and then searching for others for the remaining groups. There is some confusion over the perceived role of the spotter on the beach; theoretically they are supposed to look for turtles and indicate their location to the guide and then continue looking for more turtles. It is important, therefore, that the role of the spotters is clearly defined and explained to both the spotters and the tour guides, to avoid any misunderstandings and problems on the beach Satellite Tracking Project The two turtles successfully fitted with satellite transmitters during the 2009 Green Turtle Program were the first to be tracked from Tortuguero since 2002, and will provide further information about the migration behavior of the green turtles population nesting at this important beach. It was very interesting to follow the two females during the inter-nesting period, in which both turtles remained in near-shore waters. Once they had finished nesting both females immediately left the nesting beach and crossed into Nicaraguan waters; their migration routes were almost identical, as they stayed close to the shore heading northwards before reaching their feeding ground (See maps in Appendix 4). At the foraging ground the two turtles remained with a defined area, within approximately 50 miles of each. Satellite telemetry is a very useful tool for researchers to investigate the migratory behavior of sea turtles once they leave the nesting beach, and to determine the location of their feeding grounds; to assess potential threats that they might face either on route or once at their foraging site. Furthermore, it can be a useful educational tool, providing an exciting way in which to engage the general public in science and conservation initiatives. The on-line Tour de Turtles event organized by CCC allows people the opportunity to follow sea turtles during their migrations, while at the same time raising awareness about a variety of different threats to turtles and their habitats, through the campaigns of each of the turtle competitors. In Tortuguero several hundred people, tourists and members of the local community, were able to observe the transmitter application process and the release of the turtles. The project was, therefore, very successful, both from a scientific and a public awareness perspective 54

58 5. References Carr, A., Carr, M.H. & Meylan, A.B The ecology and migrations of sea turtles, 7. The west Caribbean green turtle colony. Bull. Amer. Mus. Nat. Hist. 162, Coyne, M., Godfrey, M., Godley, B. & Lay, K Hard shell sea turtle PTT attachment protocol. On-line manual - Troëng, S. & Rankin, E Long-term conservation efforts contribute to positive green turtle Chelonia mydas nesting trend at Tortuguero, Costa Rica. Biol. Conserv. 121, Wetherall, J. A Analysis of double-tagging experiments. Fish. Bull. 80,

59 56

60 6. Appendices Appendix 1. Photographs of harpoon incident 17 June, 2009 (Courtesy of Eva Maria Merino Rivera) Pair of green turtles mating offshore Harpoon being thrown at pair of mating green turtles 57

61 Appendix 2. Nightly sea turtle encounters for the 2009 Green Turtle Program Date Leatherback Green Hawksbill New REM REN Total New REM REN Total New REM REN Total 9-Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul

62 Date Appendix 2. Continued Leatherback Green Hawksbill New REM REN Total New REM REN Total New REM REN Total 15-Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Jul Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug

63 Date Appendix 2. Continued Leatherback Green Hawksbill New REM REN Total New REM REN Total New REM REN Total 22-Aug Aug Aug Aug Aug Aug Aug Aug Aug Aug Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep Sep

64 Date Appendix 2. Continued Leatherback Green Hawksbill New REM REN Total New REM REN Total New REM REN Total 29-Sep Sep Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Oct Total Key to table New Turtles that had no tags on first encounter in 2009 REM Remigrant turtles that had tags from previous years/other projects on first encounter in 2009 REN Renester turtles that were encountered on more than one occasion during

65 Appendix 3. Photographs of environmental education activities conducted in 2009 Students from Tortuguero High School and Harker Group with posters about conservation of electricity RAs performing the play Joba and the turtles in trouble for students in Moín and Barra del Colorado Children participating in the kite workshop, and CCC staff presenting posters at the 2 nd annual Tortufest 62

66 Photograph exposition during the celebrations of the 34 th anniversary of Tortuguero National Park CCC staff, RAs and children from the community participating in Independence Day festivities and a masked parade Junior RAs, and CCC staff at the 8 th Student Sea Turtle Symposium 63

67 Appendix 4. Photographs of the satellite transmitter attachment process and migration maps of the two green turtles tracked during 2009 Photographs Sabine Bernert 2009 Members of the public waiting to see the turtle CCC staff explaining the transmitter attachment process to tourists Attaching the transmitter using epoxy adhesive Cleaning the carapace before attachment of the transmitter Chica returns to the sea, watched by Junior RAs, ACTo staff and members of Tortuguero community 64

68 Appendix 4. Continued Maps showing migration routes of Aurora and Chica ; on leaving the near-shore waters close to the nesting beach at Tortuguero at the end of the season, both turtles made an almost identical migration, remaining in the shallow coastal waters of Nicaragua up towards their foraging area. Both turtles traveled to the same location and remained within a 50 mile radius of each other, presumably on sea grass beds. 65

69 Appendix 4. Continued Close-up detail of foraging areas of Aurora and Chica off the coast of Nicaragua; notice that both turtle appear to be foraging within a defined area close to the two small islands that can be seen in the upper right-hand corner of each map. 66