Sea turtles

Proceedings of the Technical Workshop on Mitigating Sea Turtle Bycatch in Coastal Net Fisheries

Abstract:

Sea turtles are adversely affected by a range of factors, some natural and others caused by human activities, such as fishing operations. As a result, all sea turtle species whose conservation status has been assessed are listed as threatened or endangered in the International Union for the Conservation of Nature’s Red List. While the understanding of the relative risks of the full suite of mortality sources for individual turtle populations is generally poor, there is growing evidence that small-scale artisanal fisheries may be the largest single threat to some sea turtle populations.

Coastal passive net fisheries use gillnets, trammel nets, pound nets, fyke nets and other static gear that catch, and in some cases, drown turtles. Small-scale fisheries have the potential to substantially contribute to sustainable economic development. However, to secure their long-term economic viability and to ensure conformance with international guidelines for the conduct of responsible fisheries, they need to mitigate problematic bycatch of sea turtles and other sensitive species groups. Such mitigation approaches are part of an overall effective fishery management framework that includes measures to prevent the overexploitation of all retained and discarded catch, as well as unobserved fishing mortalities.

Forty-nine participants from 17 countries, representing fishery bodies and other intergovernmental organizations, national fishery management authorities, environmental non- governmental organizations, academic institutions, fishing industries and donor organizations attended the Technical Workshop on Mitigating Sea Turtle Bycatch in Coastal Net Fisheries from 20-22 January 2009 in Honolulu, U.S.A. The five workshop co-hosts were the International Union for the Conservation of Nature, Western Pacific Regional Fishery Management Council, Southeast Asian Fisheries Development Center, Indian Ocean – South-East Asian Marine Turtle MoU and the U.S. National Marine Fisheries Service Southeast Fisheries Science Center.

Accomplishments

This workshop represented the first opportunity for experts from multiple disciplines relevant to this issue to meet to share information from 20 coastal net fisheries worldwide to disseminate and transfer best practices for sea turtle bycatch assessment and mitigation. Accomplishments during the three-day workshop included:

  • Identifying the status of assessment and mitigation activities of fisheries represented at the workshop;
  • Describing the state of knowledge for the effective and commercially viable (economically viable, practical, safe) mitigation of sea turtle capture and mortality in coastal passive net fisheries;
  • Identifying characteristics of coastal passive net fishing gear and methods likely to have a significant effect on sea turtle and target species catch and mortality rates;
  • Identifying research priorities to advance promising new turtle-friendly fishing gear and methods, based on the understanding and gaps in knowledge of why and how sea turtles interact with passive net gear, and the understanding of gear characteristics that significantly affect turtle capture and mortality rates;
  • Exploring the full suite of tools available to assess, mitigate and manage sea turtle bycatch in artisanal fisheries;
  • Identifying a list of optimal information to understand the degree of risk a fishery poses to sea turtles and identify mitigation opportunities;
  • Sharing lessons learned of effective and ineffective practices and approaches for working with artisanal fishing communities to assess and manage bycatch; and
  • Fostering partnerships and catalyzing assessments, commercial demonstrations and mitigation activities identified as priorities during the workshop, in part, by transferring the lessons learned in the few net fisheries where progress has been made to priority fisheries in other regions.

Range of Potential Fishery-Specific Solutions

Several practices were identified as having the potential to effectively avoid, minimize and offset sea turtle capture, and improve the survival prospects following gear interactions in coastal passive net fisheries. Bycatch mitigation practices discussed during the workshop included: modifications to fishing gear and methods; gear restrictions; marine protected areas (temporal and spatial restrictions on fishing); changing to a gear type with lower turtle interactions; and handling and release best practices. However, participants recognized that the efficacy at reducing sea turtle capture rates, economic viability, practicality and safety are fishery-specific and therefore fishery-specific assessment is required before recommending a mitigation approach.

Priority Gaps in Understanding

Participants identified priority gaps in knowledge warranting further investment in order to advance mitigating sea turtle bycatch in coastal net fisheries. There is a need for:

  • A generic decision tree or logic framework process tool, which could be used as a starting point to guide artisanal fishery-specific assessment and mitigation activities;
  • Improved understanding of why turtles interact with coastal net fishing gear (e.g., are they attracted to the catch and/or floats); how turtles interact with the gear (e.g., what mechanism is responsible for capture [gilling, entangling, entrapping], and in which part of the gear are turtles captured); how the gear behaves under actual fishing conditions; what characteristics of the gear design, materials and fishing methods are significant factors affecting sea turtle capture and mortality rates; and, ultimately, what the opportunities are for mitigating turtle capture, injury and mortality;
  • Standardized terminology and a classification scheme for coastal passive net fishing gear, focusing on factors that significantly affect sea turtle capture and mortality rates;
  • Standardized units to report sea turtle catch-per-unit-of-effort (e.g., catch per trip, set, unit length of net, unit area of net, unit area per soak time, net weight).
  • Accurate data on the relative impact of coastal net fisheries and other anthropogenic hazards on the long-term viability of sea turtle populations, so that limited resources can be allocated to address priority threats, accounting for the likelihood that interventions will successfully mitigate targeted anthropogenic mortality source;
  • Characterizations of the degree of risk individual fisheries pose to affected sea turtle populations, based on accurate assessments; and
  • Improved understanding of the indirect effects that coastal net fisheries have on sea turtles (e.g., obstacle to critical habitat and migration routes, ghost fishing, repeat captures, altered diet from depredating catch from gear, reduced predators or prey populations), information that is needed to produce precise risk characterizations.

Gear Technology State of Knowledge

Empirical evidence of the fishery-specific efficacy and commercial viability of gear technology approaches (changes in fishing gear designs and materials and fishing methods) at mitigating sea turtle capture in coastal net fisheries is available from only a small number of fisheries and studies. The following are gear technology approaches that have been shown to significantly reduce sea turtle catch rates in individual gillnet fisheries:

  • Reducing net profile (vertical height);
  • Increasing tiedown length, or eliminating tiedowns;
  • Placing shark-shaped silhouettes adjacent to the net; and
  • Illuminating portions of the net using lightsticks.

Of these techniques, only net illumination was found to not cause a significant decrease in target species catch rates.

In coastal poundnets, several turtle bycatch mitigation approaches have been explored:

  • Replacing mesh with ropes in the upper portion of leaders has been observed to cause a significant reduction in the turtle capture rate with an increase in catch rate of one target species and no significant difference in catch rates of four other target species;
  • Incorporating a prototype turtle releasing device into the roof of a cone-shaped pound in the small-scale southern Japan pound net fishery resulted in high escapement of green sea turtles with nominal target species escapement
  • Modifying the roof of the pound in the Japanese large-scale pound net fishery to a rectangular-pyramid-shaped pound with the top angled at 20 degrees toward the apex effectively directed turtles towards the roof apex of the pound, where an escapement device could be situated.
  • Observations document that pound nets with open versus closed capture chambers (also referred to as pounds or traps) have higher survival rates of captured turtles.

Broad assessments in individual fisheries must precede advocacy for uptake of specific turtle bycatch reduction methods. This is because there are several locally variable factors that significantly affect sea turtle and target species catch rates, and industry acceptability of any reductions in catch rates of commercially important species will depend on the local socioeconomic and regulatory context.

Gear Technology Research Priorities

It is unclear at this incipient stage in investigating this conservation issue whether or not gear technology approaches will be an effective and commercially viable solution to sea turtle interactions in most coastal passive net fisheries. Several promising new approaches warrant additional or new investigation:

  • Fishing at sufficiently shallow depths, and increasing net liftability by adjusting the weighting design and/or anchoring system to allow captured turtles to reach the surface and breathe during the gear soak, increasing the proportion of caught turtles that survive the gear interaction;
  • Minimizing gear soak time/time between patrolling gear in order to reduce the time incidentally caught turtles remain in the gear;
  • Using alternative net materials and illumination to reduce the risk of turtle capture. For instance, making the upper portion of nets more visible, while leaving the lower portion relatively undetectable might be an effective and economically viable method. Using a clear, UV-absorbent plastic material for netting could reduce turtle bycatch without compromising fish catch rates. Using coarse multifilament line in place of monofilament in the upper portion, embedding luminescent materials into netting material and incorporating lightsticks are additional strategies to increase net visibility for turtles but not for target fish species. Continuing research on the effects on turtle and target species catch rates from alternative spectral frequencies and light brightness for net illumination is needed;
  • Using buoyless floatlines might reduce turtle attraction to the gear and entanglement in the floatlines. Modifying float characteristics and reducing the number of floats and vertical float lines might reduce turtle attraction and incidence of entanglement in floatlines and the net;
  • Conducting research, development and trials of devices to avoid and minimize turtle entrance into pound net and fyke net traps, such as use of a deflector grid;
  • Modifying baiting techniques, in cases where baiting is used;
  • Setting gear perpendicular to the shore to reduce capture rates with nesting females, and exploring effects of other gear orientations to and distance from the coastline;
  • Continuing research on reduced net profile and increased length or elimination of tiedowns. Expanding this to research if increasing the net hanging ratio (ratio of net height to net width) reduces turtle entanglement risk;
  • Continuing research on using shark-shaped silhouettes. For example, constructing the silhouette from clear UV-absorbent plastics instead of PVC and plywood could retain the turtle deterrent efficacy but avoid the reduced target species catch rate observed in trials. There is also a need to develop an improved attachment mechanism;
  • Developing other sea turtle deterrents, such as chemical olfactory repellents or acoustic repellents;
  • Using alternative net materials (appropriate twine diameter and material) to produce a breaking strength that allows turtles to break free of the gear and escape;
  • Continuing research, development and testing of prototype turtle escapement devices for use in different types of pound net and fyke net gear;
  • Continuing research on shapes of catchment chambers of pound nets with the aim of consistently directing turtles towards a location where an escapement device could be incorporated; and
  • Investing in research, development and testing of equipment to disentangle turtles caught in nets (e.g., purpose-made line cutters, selecting a headlamp light color to reduce turtle stress during handling).

Consideration for Successful Artisanal Fishery Assessments

Participants identified optimal information to collect through fishery assessments in order to understand the degree of risk a fishery poses to sea turtles and to identify mitigation opportunities. Participants identified four broad categories of information to be collected during fishery assessments:

  • Magnitude of the problem both in terms of effect on sea turtle populations (conservation status of affected turtle populations, age classes affected, status and trends in levels of turtle mortality from fishery interactions, and ultimately are population-level effects occurring) and effect on the fishery (gear damage and loss from interactions, time to remove turtles from the gear and repair or replace gear, lost catch, effects of any relevant regulatory measures);
  • Fishery characterization, including gear types used, characteristics of each gear type, fishing operations, and catch characteristics;
  • Management framework (self-management, co-management, or no management), including monitoring, control and surveillance; and
  • The socioeconomic context.

Considering potential socioeconomic effects of alternative sea turtle bycatch mitigation practices was seen as a fundamental requirement to achieve successful sea turtle bycatch management. This includes considering all potential effects on a fisheries’ commercial viability, including economic viability, practicality, and crew safety. Long-term data series may be needed to account for high inter-annual variability in gear used, gear designs, fishing grounds, turtle interaction rates and other fishery characteristics.

Pros and cons were discussed for alternative assessment practices, including: social surveys; onboard and dockside observers; logbooks; satellite imagery (to observe number of participating vessels); and electronic vessel monitoring systems in combination with data on spatial distribution of turtle abundance (to provide an indirect index of turtle interactions). At-sea data were seen as optimal for understanding catch characteristics and rates, noting that limited observer coverage can provide an index of the fleet as a cost-effective preliminary assessment.

Fisher surveys were seen as useful in providing a first order qualitative understanding of whether or not problematic sea turtle capture levels are occurring and an initial understanding of the magnitude of the problem. Techniques to optimize the quality of results from social surveys were discussed.

Practices and Approaches to Work with Artisanal Fishing Communities

Participants discussed reasons why direct participation of artisanal fishers is critical for successful fishery assessment and bycatch mitigation activities. Fishers have a large repository of knowledge, which can be tapped to contribute to finding effective and commercially viable solutions to problematic bycatch that will ultimately be acceptable to the artisanal fishing community. To optimize the likelihood of fishers adopting measures identified as effective at reducing unwanted turtle bycatch, fishers must first be convinced that catching turtles is a problem and then must buy into the use of the mitigation practices.

Considerations and lessons learned for maximizing the direct participation of artisanal fishers and effectively working with artisanal fishing communities were identified and discussed. For instance, identifying progressive individuals in a fishery who are open to consider changes and lead by example, the need for a sufficiently long-term investment to develop the credibility needed to gain the trust and access of stakeholders, and expertise needed on teams working with artisanal fisheries to mitigate bycatch were highlighted.

Next Steps

Participants committed to pursue development of a decision tree process tool to guide future interventions with artisanal fishing communities, to further explore sea turtle sensory physiology and behavior with an aim to identify differences with target species, to expand collaborative research on gear technology approaches to mitigate sea turtle bycatch in coastal passive net fisheries, and to contribute to finalizing an in-progress IUCN technical report Mitigating Sea Turtle Bycatch in Coastal Passive Net Fisheries. On-the-ground assessment, commercial demonstration and mitigation activities will hopefully folllow as a result of the workshop, leading to direct sea turtle conservation benefits, and improved environmental sustainability and long- term economic and social viability of passive coastal net fisheries. 

Date
2009
Data type
Research report
Theme
Research and monitoring
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2003

Abstract:

St Eustatius National Parks Foundation (STENAPA) is the only environmental non-governmental organization on St Eustatius. In 1996, the Island Government gave legal mandate to STENAPA to manage a new marine park.

The Marine Park maintains dive and yacht moorings and conducts many programs such as the Snorkel Club, the Junior Ranger club, surveys of marine life, school educational activities and since 2002, the conservation of sea turtles on St Eustatius.

Until present, three species of marine turtles are nesting on the St Eustatius beaches: the Leatherback (Dermochelys coriacea), the Green Turtle (Chelonia mydas) and the Hawksbill (Eretmochelys imbricata).

STENAPA’s second annual turtle monitoring program started on April 17, 2003. In June 2003, Nicole Esteban (STENAPA Manager) was appointed country coordinator for WIDECAST to replace the previous manager.

STENAPA has four permanent staff and is able to undertake projects such as the sea turtle conservation thanks to two international volunteer programs that started in 2001 and 2003.

Methodology for the 2003 programme included:

  • Volunteers participating in the programme receive a theoretical and practical training on the sea turtle monitoring programme.
  • When a sea turtle is observed nesting on Zeelandia Beach, the turtle width and length is measured, location of the nest is recorded and measured and the turtle is tagged by trained personnel who are in charge of nightly patrols.
  • STENAPA conducted video interviews of two elderly Statians in June 2003, to document historical information about the number and species of turtles. Information is now known about turtle nesting and hunting as early as the 1920’s.
  • Hatchling emergence from the nest is monitored and nests are inventoried.
  • In 2003, staff used GPS mapping to monitor beach erosion, sand movement and to identify nest location of sea turtles.
  • In 2003, STENAPA arranged a series of beach clean ups, schools and businesses presentations.

Results for the 2002 and 2003 Sea Turtle Monitoring Programme are as follows:

  • A minimum of 3 Greens and 1 Hawksbill nested in 2002.
  • A minimum of between 3-10 Leatherbacks, 2-3 Greens, 2-5 Hawksbills came and nested in 2003.
  • In 2003, two measurements on two Hawksbill turtles were taken, and in 2002 two measurements on two Green turtles were collected.
  • In 2003 one Hawksbill was tagged twice on the front right and the front left flipper. In 2002, three Greens were tagged on the front flippers.
  • A total number of 41 hatchlings were rescued in 2003.

Management Recommendations:

Recommendations for the 2004 programme include:

  • Increased supervision of Working Abroad night crew members: either the Sea Turtle Programme Coordinator or Marine Park Interns (Marine Biologists) will be in charge of night patrols.
  • Purchase of additional equipment to facilitate night patrols.
  • Training of staff at international meetings.
  • Monitoring of sunset emergence as soon as a dedicated truck for the turtle programme can be purchased.
  • Beach mapping to be conducted regularly to monitor changes and map turtles.
  • Continuation with the community education programme at schools and local businesses.

It is expected that, with a full time programme coordinator, improved monitoring and increased number of volunteers, there will be increased numbers of turtles monitored in 2004. 

Date
2004
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Eustatius

Activity Report on the Dutch Caribbean Nature Alliance Sea Turtle Satellite Tracking Project 2006

Date
2007
Data type
Research report
Theme
Education and outreach
Research and monitoring
Geographic location
St. Eustatius
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2004

Abstract:

The Sea Turtle Conservation Programme is managed by St Eustatius National Parks Foundation (STENAPA), which is the main environmental non- governmental organization on St Eustatius (also known as Statia).

Recent records of turtle nesting activities on St Eustatius date from June 1997 with the discovery of a nest by Jaap Begeman. Until this date, it was believed that leatherback turtles no longer nested on St Eustatius.

Since 2001, there have been confirmed nesting of three species of marine turtles: the Leatherback (Dermochelys coriacea), the Green Turtle (Chelonia mydas) and the Hawksbill (Eretmochelys imbricata). It is possible that the Loggerhead (Caretta caretta) is nesting on St Eustatius, and there was an unconfirmed sighting in 2004.

STENAPA has four permanent staff and is able to carry on with projects such as the sea turtle conservation thanks to two international volunteer programs: the STENAPA Internship programme and Working Abroad programme started in 2001 and 2003 respectively.

The St Eustatius Sea Turtle Conservation Programme is part of the Wider Caribbean Sea Turtle Conservation Network and follows its monitoring and tagging protocols.

In order to participate in the programme, volunteers follow a theoretical and practical training at STENAPA.

In the latter half of 2004, monitoring extended to six beaches with regular day and night patrols.

In 2004:

  • Two Green sea turtles were flipper tagged, 22 Green turtles nesting events were recorded, of which three were observed (with two successful lays) and 13 dry runs recorded.
  • Four Leatherback turtles were flipper tagged and two were pit tagged. 16 Leatherback nesting events were recorded, eight of these events were observed, (with seven successful lays), two dry runs were recorded in total.

A total of six Green turtle nests and seven Leatherback nests were inventoried:

  • STENAPA personnel recorded that it takes between 44 and 51 days for a Green turtle nest to emerge, and noted that it takes 50-57 days for Leatherback nests left in situ to emerge, and 64-66 days for relocated nests to emerge

In 2004, the sea turtle conservation programme reached the local and international communities. Three methods of publicizing the programme were used: STENAPA newsletters, STENAPA radio show and press releases.

Achievements for 2004 includes:

  • Continuation of beach clean up;
  • Beach mapping;
  • Police participation to enforce laws in regards to sea turtles protection (e.g: sand mining and beach parties);
  • Additional staff training (e.g: WIDECAST AGM and Sea turtle Symposium 2005);
  • Increased volunteer supervision; and
  • Monitoring of six nesting beaches thanks to the purchase of a dedicated vehicle for the programme. 
Date
2005
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Eustatius

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2005

Abstract:

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 hawksbills turtles.

Daily track surveys are carried out on Zeelandia Beach and Turtle Beach throughout the nesting season; the other nesting beaches are 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.

In 2005:

  • Track surveys were conducted from 5 April to 21 November; a total of 190 surveys were completed.
  • Leatherback nesting activity occurred from 29 March – 22 June; 11 nests and eight false crawls were observed; all emergences were on Zeelandia Beach.
  • Green turtles were recorded from 4 July – 1 October; 15 nests and 52 false crawls were encountered; nesting was on Zeelandia Beach, Turtle Beach and Kay Bay.
  • Two hawksbill nests were observed on 27 May and 19 September; the first was on Kay Bay, the second on Zeelandia Beach.

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.

In 2005:

  • Night patrols were conducted from 18 April – 20 October; 165 patrols were completed, totalling over 1,000 hours of monitoring.
  • Three leatherbacks and five green turtles were encountered during patrols; all were tagged by the Programme Co-ordinator.
  • One of the green turtles was carrying a tag that had originally been applied in August 2002; this was the first record of a remigrant turtle for the project.

Average carapace measurements for females nesting in 2005:

  • Leatherback: Curved carapace length (CCL) = 148.2cm; Curved carapace width (CCW) = 111.6cm
  • Green: CCL = 108.8cm; CCW = 100.0cm
  • No hawksbill turtles were encountered during night patrols.

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 observers record signs of hatchling emergence. Two days after tracks have been recorded the nest is excavated to determine hatching and emerging success.

In 2005:

  • 28 nests were marked; 11 leatherback, 15 green and two hawksbill
  • Two nests were lost during the incubation period; one leatherback nest was washed away during high tides and one green turtle nest was buried underneath a cliff fall.
  • Incubation period for leatherbacks was 60 days, for greens 58.6 days and for hawksbills 63 days.

Excavations were performed on 20 nests; eight leatherback, 10 green and 2 hawksbill.

  • Average egg chamber depth varied greatly between the three species; leatherback = 73.5cm, green = 57.5cm and hawksbill = 44.5cm
  • Mean clutch size for each species; leatherback = 77.8 yolked + 48 yolkless eggs; green = 101.2 eggs and hawksbill = 147 eggs.
  • Hatching success was greater for green nests than either hawksbill or leatherback; 76.8% compared to 41.1% and 3.5%, respectively.
  • Emerging success was lower for leatherback nests than either hawksbill or greens; 2.1% compared to 41.1% and 70.1%, respectively.
  • Very little predation was observed and few deformed embryos were recorded; one albino green turtle hatchling was encountered, and one green turtle egg contained twin embryos.
  • One green turtle nest was relocated 25 days after it was laid, due to the risk of erosion; the eggs appeared relatively unaffected by the relocation, for when excavated the hatching success was 76.4%.
  • In future years the practise of relocating nests laid in erosion zones to safer sections of the beach will continue.

A satellite tracking project was initiated in 2005 by the Dutch Caribbean Nature Alliance. This research was an inter-island collaboration of STENAPA and the Nature Foundation St Maarten. Dr Robert van Dam was the lead biologist, providing expertise and training in satellite telemetry methodology.

  • Two transmitters were successfully deployed on nesting females; one on a green turtle from St Eustatius in September, the second on a hawksbill from St Maarten in October.
  • The green turtle returned to nest once more after the transmitter was attached; she then remained in the near-shore waters of the island, less than 5km from the release site on the Atlantic coast. This may be the first record of an adult green turtle female being resident in her breeding area. Transmissions ended on 15 November, 2005.
  • The hawksbill turtle migrated over 350km; she travelled to the British Virgin Islands, before her transmissions stopped on 14 December, 2005.
  • An extensive education programme was part of the project. Island schools were visited by the Programme Co-ordinator and students aged 5 – 13 were taught about satellite telemetry and its use in turtle conservation. Several newspaper articles were published, and radio interviews given; in addition an exhibit was organised at the local library.
  • Two competitions were organised for students; for the “Name the Turtle” Competition students had to draw a picture of a turtle, write a story about a turtle or make a model turtle out of recyclable materials. 106 entries were received; three winners were chosen and they won various prizes, including the chance to pick the name of one of the transmitter turtles. A similar competition was held on St Maarten. The green turtle was given the name “Miss Shellie” and the hawksbill was called “Archy”.
  • The “Where’s the Turtle?” Competition had students guessing where the turtles would go on their migrations, and how far they would swim. The winners will be informed early in 2006.

Beach erosion continued on Zeelandia Beach in 2005:

  • Many of the numbered marker stakes were lost from 2004, due to high tides.
  • Over 20% were more than 2m from their 2004 location, suggesting extensive cliff erosion.
  • Sand mining compounds the erosion problem at the northern end of Zeelandia Beach. Despite being an illegal activity it occurred throughout 2005, in the gulley and on the beach
  • Five major cliff falls were recorded; each month from June – October.
  • Monitoring of erosion will be a priority for 2006.

Several different community activities were conducted in 2005:

  • A puppet show was organised for local schools and the after school programme to teach about several threats to turtles, and how they could be avoided.
  • Presentations on turtles were given at the Auxiliary Home and the Methodist church.
  • STENAPA participated in the School Vacation Programme; Antonio Flemming assisted with night patrols in his second year of the project.

Six beach clean-ups were conducted on Zeelandia Beach. A total of 12 trucks full of rubbish bags were removed in addition to a fridge, large rope, fishing net and car batteries. Unfortunately support from the local community in these events was disappointing.

The Sea Turtle Conservation Programme was featured in regular articles in the local press and on the radio. The STENAPA quarterly newsletter included two features about the research activities conducted in 2005 and the website contains several pages dedicated to the programme, with a focus on the Sea Turtle Satellite Tracking Project 2005.

Staff participated in several regional and international meetings in 2005:

  • The 2004 Programme Co-ordinator attended the 25th International Sea Turtle Symposium in Savannah, Georgia, USA, 16 – 22 January 2005 and the WIDECAST Annual General Meeting. A teacher from the high school and a student also travelled to the symposium.
  • The 2005 Programme Co-ordinator was invited to a workshop in Cuba; the focus of this meeting was to discuss the role of community involvement in sea turtle conservation projects. She gave a presentation about the programme on St Eustatius.
  • In October the Programme Co-ordinator gave a lecture as part of the “Sea & Learn on Saba” event; the work of the Sea Turtle Conservation Programme was presented to international biologists, tourists and local residents.

Management Recommendations:

Several recommendations were made for the 2006 season:

  • Continued participation of volunteers, from Working Abroad and the STENAPA Intern Programme.
  • 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, with the possible inclusion of leatherback turtles. 
Date
2006
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2011

The aims of this Annual Report include the following:

 Summarize the activities of the 2011 Sea Turtle Conservation Program.

 Review the accomplishments and deficiencies of the program in 2011.

 Suggest recommendations for the 2012 program.

 Provide a summary of the data from 2011 research initiatives.

 Present information locally, regionally and internationally about the research and monitoring program on the island.

 Produce a progress report for the Island Government, potential program funding organizations, the local community and international volunteers.

Date
2012
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2010

The aims of this Annual Report include the following:

• Summarize the activities of the 2010 Sea Turtle Conservation Program.

• Review the accomplishments and deficiencies of the program in 2010.

• Suggest recommendations for the 2011 program.

• Provide a summary of the data from 2010 research initiatives.

• Present information locally, regionally and internationally about the research and monitoring program on the island.

• Produce a progress report for the Island Government, potential program funding organizations, the local community and international volunteers. 

Date
2011
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2009

This Annual Report includes:

• Summarize the activities of the 2009 Sea Turtle Conservation Program.

• Review the accomplishments and deficiencies of the program in 2009.

• Suggest recommendations for the 2010 program.

• Provide a summary of the data from 2009 research initiatives.

• Present information locally, regionally and internationally about the research and monitoring program on the island.

• Produce a progress report for the Island Government, potential program funding organizations, the local community and international volunteers.

Date
2010
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

St. Eustatius Sea Turtle Conservation Programme - Annual Report 2008

Abstract:

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.
Morning track surveys are carried out on Zeelandia Beach and Turtle Beach throughout the nesting season. The other nesting beaches were monitored weekly. Every track is identified to species; categorised as a false crawl, activity or a nest; all confirmed nests are included in the nest survival and hatching success study.
In 2008:

  • Morning track surveys were conducted daily from 13 March to 6th November; a total of 238 index beach morning surveys were completed.
  • 20 confirmed leatherback nests (from deposition observation or excavation proof) were recorded from 13th March – 14th June on Zeelandia Beach (stakes 1-17); in addition, four probable lays and two false crawls were recorded.
  • Green turtles were recorded from 26 July until 14th October; 46 Activities were recorded including 1 confirmed nest, 14 probable lays and 31 false crawls.
  • Hawksbill turtles were observed from the 8th of April until 10th of September. A total of nine activities were recorded. Four were potential nests and 5 were tracks only.

Night patrols are only conducted on our index beach, Zeelandia to Turtle Beach due to limited personnel and minimal nesting on other beaches; patrols run from 9:00pm – 03:30am. 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.
In 2008:

  • Targeted night patrols were conducted from 24th March – 05 October; 74 patrols were completed, totalling 499.5 hours of monitoring.
  • 19 leatherback, 1 hawksbill and 5 green turtles were seen giving a 32% encounter rate.
  • Five individual leatherbacks were observed during patrols; all received external flipper tags and 3 received PIT tags. Biopsy samples were taken from these turtles.
  • Leatherback 133713290A, observed on 12th of May was originally tagged by STENAPA in 2002, again in 2004 and received new flipper tags in 2008. Leatherback 023*359*883 also received new flipper tags; this turtle was originally tagged in Trinidad and Tobago 2005.
  • No hard shell species were tagged or observed nesting during the 2008 season.

Average carapace measurements for female Leatherbacks nesting in 2008:

  • Leatherback: Curved carapace length (CCL) = 156.1 cm; Curved carapace width (CCW) = 115.6 cm.
  • No Greens or Hawksbills were measured for fear of disturbance in 2008.

All located leatherback nests were included in a study of nest survival and hatching success. During morning track surveys false crawls and probable nests were marked. Close to the expected hatching date the observers recorded signs of hatchling emergence. Two days after hatchling tracks had been recorded the nest was excavated to determine hatching and emerging success.
In 2008:

  • Only the confirmed leatherback nests were included in this study.
  • All probable hard-shell nests were lost due to storms, swash and flooding.
  • Mean incubation period for leatherbacks was 69 days.

Excavations were performed on 14 nests; 13 leatherback and the unmarked green nest. Many nests could not be found for excavation purposes.

  • Average egg chamber depth was 77.8 cm for the leatherback and one green nest = 47cm.
  • Mean clutch size for leatherback = 79 yolked + 35.8 yolkless eggs and the green nest = 116 yolked + 0 yolkless eggs.
  • Nine nests hatched or partly hatched out of 13 excavated Leather back nests, 4 were unsuccessful nests.
  • Leatherbacks showed a very low mean hatching success rate at 7.27% of the 13 excavated nests and 41.81% emerging success in 2008.

Turtle incidents amounted to one injured and four dead turtles in 2008, the highest annual number since commencement of the turtle conservation program.

  • On Sunday, the 23rd of March, an Olive Ridley (Lepidochelys olivacea ) was found dead entangled in a net at Lynch bay by local citizens of Saint Eustatius. This has been the first confirmed presence of an Olive Ridley turtle in Statian waters.
  • A small green turtle was observed by the Marine Park Manager and turtle intern on the 27th of April at 16:00 when returning from a dive. The injured turtle was seen on the surface just outside of the harbour pier and appeared to be stuck on the surface.
  • On April 28th a small (10-50cm) suspected green turtle was found by Alain Beurgur (Scubaqua) at STENAPA reef during a night dive and was described to be cut in half. The Marine Park Manager and the Turtle intern were informed the next morning and immediately inspected the site. No turtle was found and it is suspected that the carcass had been taken by a shark during the night.
  • The Marine Park Manager was alerted on the afternoon of July 6th to the presence of a stranded Hawksbill Turtle just out from the Twelve Guns snorkel site. On arrival Mr. Munson was greeted by Mr. Van Duren and was shown the turtle, which was deceased being severely tangled in green fishing net with no noticeable lacerations or body damage.
  • On the morning of 13th of September 2008, The Marine Park Manager accompanied by a STENAPA volunteer came across a dead Hawksbill at Lynch Beach. Biometrics were taken and the animal showed no obvious cause of death.

Beach erosion continued on Zeelandia Beach in 2008:

  • Many of the numbered marker stakes were lost due to high tides. Approximately 30 were replaced in March and the beach re-staked.
  • Beach mapping and erosion monitoring continued this year. Data were collected in March, July, September and October.
  • Sand mining compounded the erosion problem at the northern end of Zeelandia Beach. One summons was issued by STENAPA and fine paid by accused sand miner.
  • An estimated 20 tonnes of sand was taken from Zeelandia (at stake 14) from the 24th March to 2nd of November.
  • Beach protection efforts continued with the placement of massive boulders in front of a primary access point for sand miners.
  • Approximately 18 cliff falls were recorded from April to October.

Various community activities were conducted in 2008:

  • During July 2008, STENAPA conducted its second Summer Club for four sessions each week. A total of forty children aged eight to 13 signed up for the club which included hiking, snorkeling and turtle education activities. STENAPA’s Summer Club turtle education program ran from 2 July to 2 August every Tuesday and Thursday.

Twelve extensive beach clean-ups were conducted on our index beach, Zeelandia during Family Friday volunteer activities. The September cleanup coincided with Ocean Conservancy’s International Coastal CleanupTM Campaign on 20th September. Twelve large garbage sacks of itemized plastic, cans, rope, Styrofoam and a huge fishing net were collected on this particular cleanup. Beach cleanups were carried out by the Marine Park Manager, STENAPA staff and interns, Working Abroad volunteers, local citizens and BroadReach volunteers.

  • A total of 17 trucks full of rubbish bags were removed from the islands’ beaches.
  • During EnviroWeek in the week of 16 October the Junior Rangers, led by Parks Ranger Hannah Madden, conducted a cleanup on Lynch beach and Venus Bay. A number of island clean ups were carried out by local children in our education programs: Snorkel club and Junior Rangers.

The Sea Turtle Conservation Programme was featured in regular articles in the regional press, television and on the local radio. The STENAPA quarterly newsletter included several features about the research activities conducted in 2008. The STENAPA website contains several pages dedicated to the programme. The island videographer Dwight Barran was alerted to the beach on two occasions to video tape a nesting leatherback for local television. Reporters/dive magazine photographers also joined on a few occasions to witness and photograph nesting events.

The turtle conservation programme continued generating interest from the local population of St. Eustatius. The Marine Park Manager spoke with several interested members of the public who were keen to view the nesting activity of a turtle, nest exhumation or a hatchling release. The turtle phone was filled with a list of interested people to contact when there were possibilities for seeing turtles. This approach was very popular and a grassroots approach of connecting with marine turtles. In 2008 a total of 40 islanders and tourists joined the night patrols. Other interested Statians were called to the beach when a turtle was nesting.
Staff participated in several regional and international events in 2008:
The Marine Park Manager, Lee Munson, accompanied by the Office Administrator/Marine Park Assistant, Jessica Berkel attended a Turtle Research and Management techniques Course between October 13th – 18th, on Bonaire. Both Lee and Jessica, together with Manager, Nicole Esteban, attended the WIDECAST Annual General Meeting held on St Kitts from December 18th - 20th .
In April 2008, STENAPA welcomed its second Marine Turtle Intern, Joseph Roche to St Eustatius. Joe had previous experience working with marine turtles, especially leatherback turtles, in 2006 in Gandoca, Costa Rica. His duties included organizing the turtle aspect of the STENAPA Summer Club, coordinating beach cleanups, beach mapping and managing the data, as well as night patrols, tagging, morning beach surveys and habitat survey dives. Unfortunately Joe terminated his internship half way through the season. His partial replacement was Gerdijanne Leestemaker, our main island turtle volunteer from Holland who has shown a huge commitment and passion for nesting turtles. She has been invaluable to the success of the 2008 nesting program and has assisted in other areas at STENAP A.
In March 2008, the Zeelandia beautification project continued. The primary objective was to deter vehicles from driving on the beach, stop sand mining and prevent further erosion. A Family Friday was dedicated to replanting of palm trees and yucca plants that succumbed to the warm weather. Only a few of these plants took root and have established themselves at Zeelandia. The information signs placed at Zeelandia were routinely inspected and cleaned. 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. In 2008 the prime access point to the beach was blocked by way of huge boulders donated from a nearby construction site. This barrier offers limited protection as other access points still allow sand miners the opportunity to venture on to the beach. Our presence on the nesting beach at night dramatically reduces the instances of sand mining at Zeelandia.
Surveys for the In-Water Monitoring of Sea Turtle Aggregations in St Eustatius National Marine Park began in January 2008 in order to assess the current status and distribution of foraging turtle aggregations in the surrounding waters of St Eustatius. The foraging population is formed of greens, Chelonia mydas, and hawksbills, Eretmochelys imbricata. Surveys yielded a total catch per unit effort (CPUE) of 1.17 turtles per hour, with an average CPUE of 0.67 for greens and 0.50 for hawksbills. Greens and hawksbills were found to occupy different areas in different densities, with more greens in the less protected sea grass beds of the harbours and more hawksbills on the reefs of the reserves. Size and gender data indicate a healthy juvenile and sub-adult population for both species. Future monitoring is needed to assess any changes in this population, and active protection of the foraging grounds of these species is essential to their continued existence within the marine park.

Management Recommendations:

Several recommendations are made for the 2009 season:

  • Continued participation of volunteers, from Working Abroad and the STENAPA intern Programme. Limit beach patrols to 4 additional people.
  • Foster public awareness of the Turtle Programme within the island of St Eustatius and the Netherlands Antilles. Introduce the new intern on the radio along with the 2009 nesting season and activities for interested members of the community.
  • Continue with STENAPA Summer Club and have the Turtle Education activities integrated into a fundamental component.
  • Monitoring of nesting beaches to continue: daily track surveys on all beaches and effective night patrols of the primary nesting beach.
  • Further development of the research programme: Introduce an experimental hatchery in the “SAFE AREA” described in this report and monitor for hatching success.
  • Compare hatching success data with neighbouring islands such as St Kitts.
  • Strongly focus on relocating nests to the hatchery that may be exposed to swash, erosion, cliff fall, sand mining, runoff, and pollution.
  • A proposal to extend the satellite tracking to leatherback turtles for DCNA.
  • Continue with grant proposals that are necessary to finance equipment and activities of this programme.
  • Monitoring of the water table at Zeelandia beach should be a priority in 2009 to determine if the subterranean water levels are causing possible egg failure but more importantly accelerating possible beach erosion.
  • Continue to develop the Zeelandia Beautification Project to include a revamp of the concrete turtle, signage, plantation and possible picnic area for individuals interested in the beauty of Zeelandia Beach.
  • Make additions to the boulder barriers to deter vehicles from venturing on to the beach and organise for them to be painted during summer club.
  • Continue with the beach mapping project and make conclusions from comparisons with previous years.
  • 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.
  • Continue the in-water survey including night surveys and feeding behaviour investigations. o Continue with tissue sampling and arrange samples for processing.
  • Improve on nest marking from 2008 with more accurate triangulation, nest marking tape and a protocol that remains continuous throughout the season.
  • Approach NuStar energy and encourage a switch from white to red light for all East facing lights. This is also something to request for the lighting at the buildings that face Zeelandia beach. 
Date
2009
Data type
Other resources
Theme
Research and monitoring
Geographic location
St. Eustatius
Author

In-water monitoring of sea turtle aggregations in St. Eustatius National Marine Park

Abstract:

All species of sea turtles in the Caribbean have come under threat in recent years due to a multitude of factors. Habitat destruction and modification are playing a larger and larger role in current population declines. Trends projected from data of nesting females are useful in predicting potential shifts in populations, but such changes may not appear in adult female populations until it is too late to protect them. Changes in the populations of juveniles are a much earlier and more accurate indicator to assess the future of the population as a whole. In-water surveys of sea turtle foraging grounds are the best tool to monitor such changes in juvenile and sub-adult populations so that they can be more quickly and effectively protected.

In-water surveys began in the Statia National Marine Park in January 2008 in order to asses the current status and distribution of foraging turtle aggregations (greens, Chelonia mydas, and hawksbills, Eretmochelys imbricata) in the surrounding waters. Surveys yielded a total catch per unit effort (CPUE) of 1.17 turtles per hour, with an average CPUE of 0.67 for greens and 0.50 for hawksbills. Greens and hawksbills were found to occupy different areas in different densities, with more greens in the less protected sea grass beds of the harbors and more hawksbills on the reefs of the reserves. Size and gender data indicate a healthy juvenile and sub-adult population for both species. Future monitoring is needed to assess any changes in this population, and active protection of the foraging grounds of these species is essential to their continued existence within the marine park. 

Date
2008
Data type
Research report
Theme
Research and monitoring
Geographic location
St. Eustatius
Author