St. Eustatius Sea Turtle Conservation Programme - Annual Report 2007
The St Eustatius Sea Turtle Conservation Programme was initiated in 2001 due to concerns that the island’s sea turtle populations were being threatened due to habitat degradation and destruction. The programme is managed by St Eustatius National Parks Foundation (STENAPA), which is the main environmental non-governmental organization on the island.
The Sea Turtle Conservation Programme is affiliated to the Wider Caribbean Sea Turtle Conservation Network (WIDECAST) and adopts its monitoring and tagging protocols.
Since monitoring began, three species of sea turtles have been confirmed nesting on the island; leatherback (Dermochelys coriacea), green turtle (Chelonia mydas) and hawksbill (Eretmochelys imbricata). There was an unconfirmed nesting by a fourth species, the loggerhead (Caretta caretta), in 2004.
Five nesting beaches have been identified; Zeelandia Beach, Turtle Beach, Lynch Bay, Oranje Bay and Kay Bay. Zeelandia Beach is the primary nesting beach, and the only place where all three species nest regularly; the other beaches are used occasionally by green and hawksbill turtles.
Daily track surveys are carried out on Zeelandia Beach and Turtle Beach throughout the nesting season. The other nesting beaches were monitored sporadically. Every track is identified to species; categorised as a false crawl or a nest; all nest locations are recorded for inclusion in the nest survival and hatching success study.
- Track surveys were conducted daily from 8 March to 23 November; a total of 260 morning surveys were completed.
- Leatherback nesting activity occurred from 30 March – 18 May
- 5 leatherback nests (or probable nests) were recorded March – June on Zeelandia Beach; in addition, two false crawls and one non-nesting track were also observed on Zeelandia and Oranje Bay.
- A leatherback nesting attempt was recorded on 18 May, 2007 on Oranje Bay. The turtle attempted to nest but hit rocks and abandoned the attempt. The non-nesting track on Oranje Bay was the first reported case of a leatherback attempt to nest on the Caribbean side of St. Eustatius.
- All leatherback nests that were recorded were on Zeelandia Beach.
- A member of the public reported seeing turtle tracks on Oranje Bay behind a dive centre, Dive Statia, on 11 May, 2007. The Marine Turtle Progamme Co-ordinator investigated behind the dive centre but could not find any tracks or anything resembling a nesting site.
- Green turtles were recorded from 15 July until 16 September; 5 nests and 34 false crawls were encountered; nesting was on Zeelandia Beach but false crawls were on Zeelandia, Turtle Beach and Kay Bay.
- Hawksbill turtles were observed from the 8 July until 13 November.Two nests and false crawls were recorded. Hawksbills nested on Zeelandia (2 nests), but recorded false crawls on Zeelandia and Crook’s Castle.
Night patrols are only conducted on Zeelandia Beach due to limited personnel and minimal nesting on other beaches; patrols run from 9.00pm – 4.00am. Each turtle encountered is identified to species; tagged with external flipper tags and an internal PIT tag (leatherbacks only); standard carapace length and width measurements are taken; nest locations are recorded for inclusion in the nest survival and hatching success study.
- Night patrols were conducted from 30 March – 26 September; 119 patrols were completed, totalling 719.22 hours of monitoring.
- Three leatherback, one green turtle and two hawksbill turtles were encountered during patrols; all leatherbacks received external flipper tags.
- The first green turtle was observed on 29 July. She successfully nested and had a tag which showed that she was tagged previously in 2002. She was also observed in 2005. This turtle nested approximately four times during the 2007 season including 2 September 2007 when she was fitted with a satellite transmitter.
- No hawksbills were tagged during the 2007 season. Two hawksbills were seen but one did not break the high tide line while the other was unable to be tagged.
- One green turtle during the night patrol was selected for satellite tracking in 2007. This was the last satellite transmitter that was applied for the DCNA Turtle Tracking Project. This has been the third consecutive year that the Dutch Caribbean Nature Alliance Satellite Tracking Project has been conducted and successfully accomplished.
Average carapace measurements for females nesting in 2007:
- Leatherback: Curved carapace length (CCL) = 147.00 cm; Curved carapace width (CCW) = 110.3 cm
- Green: CCL = 110.0 cm; CCW = 105.5 cm o Hawksbill:CCL=88.0cm;CCW=73.0cm.
All marked nests were included in a study of nest survival and hatching success. During track surveys they are monitored for signs of disturbance or predation; close to the expected hatching date the observers record signs of hatchling emergence. Two days after hatchling tracks have been recorded the nest is excavated to determine hatching and emerging success.
- 12 nests were marked: five leatherbacks, five greens and two hawksbill nests.
- 2 nests were lost during the incubation period; both were leatherback nests lost due to high tides near natural nests near stake 22-25.
- Mean incubation period for leatherbacks was 58 days, for greens 55.25 days and for hawksbills was indeterminable since none survived.
- One hawksbill nest was laid on Zeelandia beach on 12 November. A local resident observed hatchlings on 31 December but after 11 days of searching, the nest could not be relocated and the nest (EI0702R) was declared “Partially Hatched”.
Excavations were performed on 12 nests; five leatherbacks, five greens and two hawksbill nests.
- Average egg chamber depth varied between the three species: leatherback = 64.67 cm, green = 53.25cm and hawksbill = 53cm.
- Mean clutch size for each species: leatherback = 66 yolked + 30.7 yolkless eggs and green = 130 yolked + 0.25 yolkless eggs. Hawksbills are indeterminable since none hatched successfully.
- Five nests hatched or partly hatched leaving one that washed away by the tide (CM0705); two that could not be located and three that failed to hatch.
- Leatherbacks showed identical hatching and emerging success rate from 2006; 21.16% hatching success compared to 21.1%, but higher emerging success of 64.58% to just 15.3% in 2006.
- Greens were more successful in 2006 and hatching success was 33.84% compared to 51.0% in 2006, but emerging success was 57.18% in 2007 and 46. 2006.
- The survival of nests varied but overall was not very high. All nests were laid on Zeelandia Beach.
- In future years the practise of relocating nests laid erosion zones to safer sections of the beach will continue.
On 29 April, 2007, a stranded leatherback turtle was encountered by the Marine Park intern, Mirella Wognum, on Zeelandia Beach during a morning track survey at approximately 08:15. Lacking the necessary equipment to perform a necropsy turtle was moved above the surf line, to ensure that it was not swept away by the tide. Later that day the remains the turtle washed northward to stake number 1. The Programme Co-ordinator, , assisted by Marine Park interns Liz Hartel and Mirella Wognum, returned and performed a rudimentary necropsy to try and determine the cause of death.
On the morning of 16th of May, STENAPA staff came across a drowned Hawksbill on the City Harbor. The juvenile hawksbill had been trapped in the net of a local fisherman and could not free itself from the nets, subsequently drowning.
On the 7th of November, a stranded Green Turtle was discovered by a local diver, Derrick Goudrian, in Oranje Bay nearby dive site Blue Bead Hole. Mr. Goudrian presented the deceased turtle to STENAPA staff which took photos and buried the juvenile Green nearby Zeelandia beach. Unfortunately the Programme Coordinator was away on holiday and unable to perform a necropsy.
A satellite tracking project was initiated in 2005 by the Dutch Caribbean Nature Alliance (DCNA) and concluded in 2007. This research was an inter-island collaboration between STENAPA and the Nature Foundation St Maarten. Dr Robert van Dam was the lead biologist, providing expertise and training in satellite telemetry methodology.
The two turtles tracked by satellite since 2006 continued into 2007. In mid-September 2006, two turtles received their tracking satellites. Lisa, a hawksbill turtle, was fitted with a satellite transmitter while Grace, the green turtle, was fitted a transmitter. Lisa’s last transmission was 1 February 2007. From the time of her nesting on Zeelandia beach until the time of her last transmission, Lisa had traveled a total of 2870km. Grace transmitted from sea grass beds off the waters of St. Kitts and Nevis. Grace’s last transmission was on 6 June 2007 at 18:18:09. During the lifetime for the transmission, Grace traveled a total of 4412km in her foraging grounds.
- On 1 September 2007, a green turtle arrived on Zeelandia Beach at 23:27. She was previously recorded in 2002 and in 2005. The Green turtle, named “Track”, attempted to nest but found the area she chose too rocky. On her wa back to the water she was placed in a turtle holding pen and her satellite transmitter was activated at 00:11. She was released back into the ocean at 03:20, Sunday the 2nd of September.
- All STENAPA volunteers and interns, along with Arturo Marine Turtle Programme Coordinator, as well as several local residents were present for this major event. The entire process was videotaped by Dwight Ba and aired on Channel 15 on 6 September from 7:30 to 8:00pm.
- Track made a brief stop at Prickly Pear Island in the itish Virgin Islands. Track then skimmed the northern coast of Puerto Rico and stopped the north-east coast of Dominican Republic. At the time of writing this report, Track was currently in the same feeding grounds of El Macao, Santo Domingo.
- STENAPA has been in contact with Yolanda Leon, a known turtle biologist from the Dominican Republic. Ms Leon stated that there are many beaches in the area where Track is located. Track entered an area of intense tourism development, however, there are nearby areas with less developed beaches and offshore sea grass. One particular beach in this area was a historically important leatherback nesting beach.
- Track’s satellite transmitter stopped responding approximately 23 December 2007. At her last transmission, she was still in the same feeding grounds as previously indicated.
- In concurrence with attaching the final satellite transmitter, the Marine Turtle Programme Coordinator visited all the island schools to give a brief presentation to all students. The motive for these visits was to educate and inform the local students of two different competitions in relation to this project.
Beach erosion continued on Zeelandia Beach in 2007:
- Many of the numbered marker stakes were lost due to high tides. Approximately, 21 were replaced.
- Beach mapping and erosion monitoring was continued this year. Data were collected February, May, August and December. Data was compared for seasonal changes as well as yearly changes. All months were compared for within the year changes. 28.13% of the stakes had recorded a positional change from the cliffs that were less than 50cm from their December positions. 40.63% of the stakes recorded a positional change of 50-100cm while 29.69% of the stakes recorded a change of over 100cm. Seventeen of the stakes moved between one to two meters while two moved more than two meters. The data do point to extensive cliff erosion, and possibly steady to accelerating erosion. Preliminary data stills needs multiple year analyses before any tangible conclusions can be made.
- Sand mining compounds the erosion problem at the northern end of Zeelandia Beach. Despite being an illegal activity, it occurred throughout 2007, in the gully and on the beach.
- Seven major cliff falls and 16 minor cliff falls were recorded from February to December. o Monitoring of erosion will be a priority for 2008. A suggestion for 2008 is to monitor erosion rates and create a water table study to see if there is a correlation.
Several different community activities were conducted in 2007:
- In 2005 the “Help Out or Sea Turtles Miss Out” programme, teaching the local communities about sea turtle conservation issues, with Education Officer Dominique Vissenburg, was particularly successful. In 2006/7, the year the focus of the school education programme was water.
- On 11 February, 2007 the Marine Turtle Program Co-ordinator gave a presentation to the public. The title of the presentation was regarding the conservation of marine turtles on St. Eustatius. Among the persons present were eight University of St. Eustatius medical students.
- On 21 March, 2007, a presentation was given to STENAPA’s Junior Rangers regarding the history of turtles in the Caribbean, their current threats and laws protecting them. The presentation was called “Sea Turtle Conservation And Laws Protecting Them”. Furthermore, in the month of December, there were also sessions with Junior Ranger I and II regarding marine turtles and their habitat.
- During July 2007, STENAPA started its inaugural STENAPA Summer Club. Twenty-four children aged eight to 13 signed up for the club which included hiking, snorkeling and turtle education activities. STENAPA’s Summer Club ran from 2 July to 2 August every Monday, Wednesday and Thursday.
- On 5 December, in conjunction, with the St. Eustatius Marine Park 10 year anniversary, a one hour seminar for the general public was given on the Biology, Ecology and History of Turtles in St. Eustatius Marine Park at the Golden Era Hotel.
Twelve beach clean-ups were conducted on Zeelandia Beach. Cleanups were performed on Zeelandia Beach, Turtle Beach, Lynch Beach and Oranje Bay. This was the first recorded time that Lynch Beach had rubbish removed from its beach. The September cleanup coincided with Ocean Conservancy’s International Coastal CleanupTM Campaign on 15 September. Beach cleanups were carried out by the Sea Turtle Conservation Programme Coordinator, STENAPA board, staff and interns, Working Abroad volunteers, local citizens and BroadReach volunteers.
- A total of 22 trucks full of rubbish bags were removed, including a large mooring rope, fishing nets, oil barrel, fishing ropes and buoys, several pallets.
- Local citizens were on hand in several beach cleanups (March, July and September).
- On 15 September 2007, volunteers gathered on Zeelandia Beach to participate in the largest singular most successful worldwide volunteer movement, the International Coastal Cleanup. This particular beach clean up was unique because it was the first time St. Eustatius National Parks, STENAPA, collaborated with The Ocean Conservancy on this event.
- During EnviroWeek in the week of 16 October the Junior Rangers, led by Parks Ranger Hannah Leslie, a cleanup was conducted on Venus Bay. This was the first recorded cleanup of Venus Bay by STENAPA.
The Sea Turtle Conservation Programme was featured in regular articles in the local press, Television and on the radio. The STENAPA quarterly newsletter included several features about the research activities conducted in 2007 and the new website contains several pages dedicated to the programme, with a focus on the culmination of the DCNA Sea Turtle Satellite Tracking Project.
A new approach was taken for the upcoming season in generating interest from the local population of St. Eustatius. The Marine Turtle Program Co-ordinator spoke with several interested members who were keen to view the nesting activity of turtle, nest exhumation or a hatchling release. A turtle phone was purchased with a list of interested people to contact when there were possibilities for seeing turtles. The new approach was popular avenue and a grassroots approach of connecting with marine turtles.
Staff participated in several regional and international meetings in 2007:
- The Programme Co-ordinator, Arturo Herrera, attended the 27th International Sea Turtle Symposium in Myrtle Beach, South Carolina USA from 25 to 28 February 2007) and the WIDECAST Annual General Meeting (23 – 24 February 2007).
- On the first week of December, STENAPA held its Ten Year Marine Park Celebration. Many activities were included and one was the hour-long Marine Turtle presentation held at the Golden Era Restaurant and Hotel on 5 December 2007.
On 10 June, 2007, STENAPA greeted its first Marine Turtle Intern, Shizu Fukui to St Eustatius. Shizu Fukui is the first Marine Turtle Intern and has d previous experience working with marine turtles, especially, leatherback turtles, in 2006 in Gandoca Costa Rica. Her duties included organizing the turtle aspect of the STENAPA Summer Club, creating a STENAPA Turtle Volunteer Manual, and spearheading a Zeelandia Beach beautification project, as well as night patrolling, morning beach surveys and habitat surveying dives.
In June 2007, the Zeelandia beautification project commenced. The primary objective is to offer an area on Zeelandia Beach where visitors can enjoy the beach. Another objective is to deter vehicles from driving on the beach, stop sand mining and prevent further erosion. On 15 June 2007, a visitor information board was installed at the primary entrance to Zeelandia Beach. 20 July 2007 was dedicated to the installation of plants and fencing at the prime Zeelandia entrances. On 7 September 2007, another Family Friday was dedicated to replanting of palm trees and yucca plants that succumbed to the warm weather. Three signs have been strategically placed at the entrances. The purpose of these signs is to educate the public about turtles that nest on the beach and remind people not to drive on the beach. STENAPA intern for the Turtle Programme, Zoe Fukui lead this project and hopes the signs will inform the public about the work of the Marine Park to protect turtles by means of nightly turtle patrols, cleaning the beach and protecting the beach from erosion.
The In-Water Survey and Monitoring project was initiated in January 2007 in order to provide fundamental data on the populations and trends of resident and migrant turtle species that use the surrounding waters of St. Eustatius. The information gathered will be used to monitor, detect trends and assess the habitats where turtles rest, nest and feed. The objective is to build on existing knowledge of the population demographics of marine turtles in the St Eustatius Marine Park. There are no previous in-water studies about the resident sea turtle populations in the area. Equipment such as ArcGIS 9.0 Software and Satellite Imagery was purchased to begin the habitat mapping of the areas where resident turtles may reside. The first habitat map for the Marine Park was produced in May 2007.
Several recommendations are made for the 2008 season:
- Continued participation of volunteers, from Working Abroad and the STENAPA Intern Programme.
- Foster public awareness of the Turtle Programme within the island of St Eustatius and the Netherlands Antilles. Utilize the new television medium along with Dwight Barran to videotape a nesting female turtle for a documentary on nesting females on St. Eustatius.
- Continue with month-long STENAPA Summer Club and have the Turtle Education feature integrated into a fundamental component.
- Monitoring of nesting beaches to continue: daily track surveys on all beaches and night patrols of the primary nesting beach.
- Further development of the research programme: expand the focus of the programme by implementing an in-water survey of juvenile turtles and continue the satellite tracking project.
- A proposal to extend the satellite tracking to leatherback turtles for DCNA.
- Monitoring of erosion should also become a priority. In addition, monitor the water table at Zeelandia beach to determine if the subterranean water levels are causing possible egg failure but more importantly accelerating possible beach erosion.
- As well as the monitoring of erosion, continue to develop the Zeelandia Beautification Project to include a concrete turtle and possible a picnics area for individuals interested in the beauty of Zeelandia Beach.
- Revitalize the in-water turtle sighting surveys with the local diving centres. This information will help make more informed decisions regarding the in-water monitoring programme.
- Create a turtle baseline study within the Marine Park and a carrying capacity survey.