Sea turtles

An Inventory of the Geographical Distribution and Conservation Status ofMarine Turtles and Sharks in the Wider Caribbean andRelationship to Fisheries

Findings on Marine Turtles
·         Migration routes to and from nesting sites (typically index beaches) are variously known in the Caribbean, increasingly from satellite telemetry and studies of genetics. Without doubt the WWF priority areas are connected to each other, as well as to others in the Caribbean and to the high seas, especially the Sargasso Sea, through their shared responsibility for marine turtles during their different life stages.
·         Nesting habitat for marine turtles in the Caribbean are reasonably well know, although data is continually accruing from existing and new projects that monitor nesting activity. The imperative is to capture and share data in a meaningful way so as to enable comparison between sites and to permit the analysis of population trends.
·         There is a growing focus on in-water monitoring which helps to shed light on foraging sites. A number of parallel efforts by coral reef researchers to monitor ecosystems also provide valuable information on coral reef health and resilience to climate change in the region. While these studies are useful in highlighting overall declines in the coral reef ecosystems upon which marine turtles depend, there was found to be lack of similar efforts to monitor seagrass habitat for marine turtles, or  water  quality  monitoring  in  what  is  a  highly  populated  region  with  increasing  coastal development that generally lacks urban environmental infrastructure.
·         MPAs in the Caribbean have not specifically been designed as a network to protect endangered marine turtles in their different life stages and habitats. There is better coverage of nesting beaches via terrestrial protected areas than of foraging sites in marine protected areas (MPAs), which also reflects the reality of competing interests from fisheries, oil exploration and infrastructure development. Effective MPAs require adequate management capacity, and enhanced enforcement capacity is a top priority need among Caribbean MPAs.
·         Threats to marine turtles are extensive. The most common threats to nesting turtles shared by the priority areas are artificial lighting, beach erosion/accretion and pollution The most common threats to foraging/migrating turtles are fisheries entanglement, bycatch and pollution. Throughout the Caribbean it is evident that financial and human resources are a major challenge for governments, NGOs and communities in taking forward marine turtle conservation efforts.
 
Findings on Sharks
·         Information relevant to sharks in the Caribbean was found to be spread throughout a wide range and a large volume of literature. The disparate sources of shark information include reports from national scientific and fisheries divisions, from regional fisheries management organizations, from multilateral  agencies,  and  from  regional  and  international  academic  institutions.   Only  one publication was found to bring together regional shark information.
·         Consultation with key shark experts indicated that much is still unknown about sharks, even for the more common shallow water species. Still less is known about pelagic sharks and their movements into and through the eco-regions of the Caribbean.
·         Information on sharks was found to be unevenly distributed amongst the priority areas covered in this inventory. More extensive information on sharks was found to exist for non-priority areas of the Caribbean, such as Venezuela and the US, than for the priority areas. The inventory serves to highlight geographical gaps in knowledge about sharks in the Caribbean, for example in relation to Cuban sharks, and these geographical could guide further investigation.
·         Insufficient data exists to determine which shark species are of possible concern in the Caribbean. Also complicating the Indices of relative abundance were found to sometimes provide conflicting information on population trends.
·         Although sharks are highly migratory, information on shark movements in the Caribbean and the Sargasso Sea comes from only a handful of sources.
·         Some landings data exists for shark fisheries and some data exists on the incidental capture of sharks in other fisheries. However, making meaningful comparisons between datasets is a complex and time-consuming task which could be undertaken with a specialist partner such as a regional fisheries management organization or a researcher.
·         There is scope to seek further input on sharks from a number of knowledgeable experts who were willing to contribute but were unavailable for consultation in the timeframe of this inventory.
·         Some of the information that was compiled in the course of the inventory was found to be old and/or limited in its coverage. Expert consultation raised a number of doubts about key references such as IUCN classification of sharks. There is a fundamental need to validate the presence of sharks in the region and assess their population status. Recommended follow-up to this inventory could be key local informant interviews with fishers and relevant local experts in each of the priority areas about shark sightings, catch and bycatch.
·         A key step towards effective management of Caribbean Sharks would be a meeting of regional shark scientists and experts to share data, assess its application to conservation and sustainable use, and to develop a strategy for addressing significant gaps in knowledge. Such a meeting focused on Caribbean sharks has not yet been achieved.
 
Recommendations on GIS
·         Continue GIS data scoping and the collection of existing information from organisations working on similar initiatives. Invest in understanding existing governance frameworks and building partnerships for future collaboration with other regional fisheries management organisations, BINGOs (TNC and ICUN),  Universities  (UWI,  CERMES),  local  and  regional  NGOs  (see  Mahon  et  al.  2013  for  full Caribbean governance review), with a view to developing a data sharing agreement with key partners. This would enable continued sharing of GIS data collected and produced with others practitioners working the region.
·         Construct a Geodatabase that addresses WWF’s strategic priorities in the Caribbean region and which fills gaps in existing GIS information for these priorities. This could provide a valuable spatial synthesis of several types of information relevant to the priority areas.
·         The largest GIS data gap is in relation to sharks. There are a number of studies on sharks (i.e. NOAA fisheries observer boats, Fisheries Division’s datasets) but this data needs to be compiled and GIS data produced, which requires more significant effort than was possible within the scope of this inventory.
·         There are also opportunities to improve GIS data related to marine turtles. Turtle migration is an example of this. There are multiple initiatives by various different turtle conservation organisations and academic institutions that are tracking the migrations of marine turtles in the region, especially by satellite.  GIS data from satellite tracking from various locations in the region exists, but it has never been compiled at the regional level for large scale analysis of marine turtle migration. This task could be usefully undertaken in future, ideally in conjunction with the WIDECAST network.
·         We note that some marine turtle data used in GIS are dynamic rather than static in nature and in the interests of data integrity they would benefit from updating. For example, new information is constantly becoming available from nesting monitoring activities, both new from new projects and the ongoing activities of longer term projects. There have also been discoveries of marine turtle aggregations at foraging sites, providing new data to input to GIS. Threats to marine turtles across the region are emerging and changing, for example in relation to tourism development, and creative approaches to GIS representation of this information could be developed to assist with monitoring impacts on population status and trends.
·         In  the  course  of  this  inventory  we  explored  some  new  approaches  to  mapping  marine  turtle populations   and   trends   with   the   aim   of   assisting   interpretation   and   enhancing   strategy development. The sample maps are based on data from Bonaire and the Guianas only, since comparable datasets were either missing for the other priority areas or could not be provided in the timeframe of the inventory.  There is potential to work further with WWF on the development of new GIS layers that directly feed into the strategy development process.
 

Date
2013
Data type
Research report
Theme
Research and monitoring
Geographic location
Aruba
Bonaire
Curacao
Saba
Saba bank
St. Eustatius
St. Maarten

Research and Monitoring of Bonaire ’s Sea Turtles: 2014 Technical Report

Sea Turtle Conservation Bonaire (STCB) was initiated in the early 1990s to protect the island’s marine turtle populations. Our current research and monitoring efforts, which were standardized more than a decade ago, include monitoring nesting beaches around Bonaire, conducting intensive in-water netting and snorkel surveys (capture-mark-recapture), and tracking post-breeding migration using satellite telemetry. These techniques provide us with a better understanding of Bonaire sea turtles’ breeding success, abundance, health, growth rates, migratory paths and distant feeding grounds, residency duration, habitat quality, and threats.
During the 2014 season, we recorded 63 nests at our index beach on Klein Bonaire. Total hawksbill (45) and loggerhead (18) nests documented there were similar to numbers observed during recent years. Across Bonaire and Klein Bonaire, we observed three species crawling 260 times, including 83 confirmed or suspected nests. Only two green turtle nests were recorded in northeastern Bonaire, whereas hawksbills and loggerheads exclusively nested on Klein Bonaire and the beaches of southern Bonaire. Total nesting activities peaked during June through August, with nesting extending through December.
We documented a much higher number of false crawls (unsuccessful nesting attempts) for both hawksbills and loggerheads in 2014 than in 2013. This phenomenon may result from a small number of individuals which were inefficient nesters (i.e., false crawled multiple times before successfully laying a nest), disturbance to turtles during nesting, and / or indicate deterioration in the quality of particular nesting sites, perhaps due to factors such as removal of vegetation. Estimates of clutch size and hatch success suggest that nearly 8,700 turtles hatched on the beaches of Bonaire and Klein Bonaire during 2014, including some 6,300 hawksbills, 2,200 loggerheads and 160 green turtles.
During in-water snorkel surveys, we observed and captured green turtles and hawksbills in all regions sampled, including Klein Bonaire, along the west coast of Bonaire, and near the reef bordering Lac. Netting in Lac and Lagoen resulted in a record number of captures during 2014, primarily green turtles. The aggregation of green turtles near Lac remains much larger than sites along the west coast, and greens captured there were bigger than conspecifics elsewhere, perhaps a result of the composition and high densities of sea grasses in Lac. Analysis of the 2013 and 2014 capture data from Lac indicates that netting during the second week of a two-week session is less efficient at capturing turtles. These results suggest that conducting netting sessions during non-consecutive weeks may be a more effective sampling strategy.
We received reports from the WIDECAST Marine Turtle Tagging Centre of 5 green turtles caught in nets by Nicaraguan fishers in the sea turtle harvest during the past 18 months. These recoveries provide invaluable information about international movements and migratory behaviors. The prevalence of fibropapillomatosis (FP) among green turtles captured in and near Lac again increased in 2014, as roughly one-third of all captures were observed with external tumors. However, we recaptured two green turtles that were previously treated to eliminate the fibropapilloma tumors. In both cases, the results were positive, perhaps suggesting that removing tumors via surgery or ligation can improve the health of individual turtles and reduce the incidence of FP in Lac.
 
Retreived from http://www.bonaireturtles.org on April 13, 2015

Date
2014
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire

Research and Monitoring Report 2013 - Sea Turtle Conservation Bonaire

We observed green turtles and hawksbills along the west coast of Bonaire, around Klein 
Bonaire, and adjacent to Lac during snorkel surveys. Green turtle sightings were 
particularly high near Lac, and netting surveys also suggested large aggregations of green 
turtles in shallow, sea grass foraging sites of Lac. Green turtles documented there were 
larger than individuals reported elsewhere in Bonaire. 
Five green turtles tagged in 2003 and 2006 were reported in Nicaragua’s sea turtle harvest, 
valuable data about sea turtle movements which complement our satellite tracking 
program. Unfortunately, incidences of fibropapillomatosis among green turtles were more 
widespread in 2013 than recent seasons. 
In 2013, we tracked a post-nesting female hawksbill turtle using satellite telemetry from 
Bonaire to Honduras over a period of 85 days. The turtle passed through six national 
territorial waters, swimming over 5,000 km (3,000 mi) to reach a general area proven to be 
important foraging grounds for Bonaire breeding turtles. 
We also outfitted a hawksbill with a datalogger to gather information on hawksbill habitat 
use and behaviors. The device, which collects GPS locations and depth information, was 
We observed green turtles and hawksbills along the west coast of Bonaire, around Klein 
Bonaire, and adjacent to Lac during snorkel surveys. Green turtle sightings were 
particularly high near Lac, and netting surveys also suggested large aggregations of green 
turtles in shallow, sea grass foraging sites of Lac. Green turtles documented there were 
larger than individuals reported elsewhere in Bonaire. 
Five green turtles tagged in 2003 and 2006 were reported in Nicaragua’s sea turtle harvest, 
valuable data about sea turtle movements which complement our satellite tracking 
program. Unfortunately, incidences of fibropapillomatosis among green turtles were more 
widespread in 2013 than recent seasons. 
In 2013, we tracked a post-nesting female hawksbill turtle using satellite telemetry from 
Bonaire to Honduras over a period of 85 days. The turtle passed through six national 
territorial waters, swimming over 5,000 km (3,000 mi) to reach a general area proven to be 
important foraging grounds for Bonaire breeding turtles. 
We also outfitted a hawksbill with a datalogger to gather information on hawksbill habitat 
use and behaviors. The device, which collects GPS locations and depth information, was 
retrieved in July, 2013. Preliminary results are consistent with previously deployed 
dataloggers, indicating regular movements in and out of Lac Bay. 
Sadly, we recorded 18 turtles stranded during 2013, 12 of which were found dead or had to 
be euthanized. 
We will be undertaking several new research initiatives in the year ahead, including using 
our tagging data to estimate the total population of sea turtles using Bonaire’s waters 
(which will help to inform management policy) and to estimate the tremendous growth 
rates of green turtles in Lac, as well as reviewing our monitoring program to ensure that 
protocols are as efficient as possible. 
 

Date
2014
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire

BioNews 14 - February 2014

This month’s issue focuses on marine monitoring. The results of the 2013 lobster fisheries monitoring project on the Saba Bank are in and on Curaçao a sea turtle monitoring programme is developing in line with regional efforts. Monitoring with standardised protocols, using appropriate methods, guarantees the collection of comparable data and provides added value to our islands and the region as a whole.

Content:

Date
2014
Data type
Media
Theme
Education and outreach
Research and monitoring
Geographic location
Aruba
Bonaire
Curacao
Saba
Saba bank
St. Maarten
Author

Population stock structure of leatherback turtles (Dermochelys coriacea) in the Atlantic revealed using mtDNA and microsatellite markers

Abstract:

This study presents a comprehensive genetic analysis of stock structure for leatherback turtles (Dermochelys coriacea), combining 17 microsatellite loci and 763 bp of the mtDNA control region. Recently discovered eastern Atlantic nesting populations of this critically endangered species were absent in a previous survey that found little ocean-wide mtDNA variation. We added rookeries in West Africa and Brazil and generated longer sequences for previously analyzed samples. A total of 1,417 individuals were sampled from nine nesting sites in the Atlantic and SW Indian Ocean. We detected additional mtDNA variation with the longer sequences, identifying ten polymorphic sites that resolved a total of ten haplotypes, including three new variants of haplotypes previously described by shorter sequences. Population differentiation was substantial between all but two adjacent rookery pairs, and FST values ranged from 0.034 to 0.676 and 0.004 to 0.205 for mtDNA and microsatellite data respectively, suggesting that male-mediated gene flow is not as widespread as previously assumed. We detected weak (FST = 0.008 and 0.006) but significant differentiation with microsatellites between the two population pairs that were indistinguishable with mtDNA data. POWSIM analysis showed that our mtDNA marker had very low statistical power to detect weak structure (FST \ 0.005), while our microsatellite marker array had high power. We conclude that the weak differentiation detected with microsatellites reflects a fine scale level of demographic independence that warrants recognition, and that all nine of the nesting colonies should be considered as demographically independent populations for conservation. Our findings illustrate the importance of evaluating the power of specific genetic markers to detect structure in order to correctly identify the appropriate population units to conserve. 

Date
2013
Data type
Scientific article
Theme
Research and monitoring

Sea Turtle Conservation Bonaire - Progress Report 2005

2005 was a very successful year for Sea Turtle Conservation Bonaire as we built upon the accomplishments of 2004. In all the program areas, staff and volunteers worked hard to move us forward in pursuit of our mission: to ensure the protection and recovery of Bonaire’s sea turtle population throughout their range.

On the research front, we observed sea turtle nesting in 2005 at lower levels than during 2004, with a total of 61 nests recorded for all the beaches of Bonaire and Klein Bonaire. The in-water surveys on the turtle foraging grounds yielded a total of 105 turtles handled, of which 21 were recaptures from 2003 and 2004. Satellite tracking of breeding turtles was again a success, with four turtles fitted with transmitters: three on hawksbills and one on a loggerhead turtle, all at Klein Bonaire. We successfully followed all tracked turtles during their long-distance migrations to their foraging grounds. We generated daily maps and gave relevant information via our newsletter to the public, creating awareness about the situation of the sea turtles around the globe.

In the area of education and public awareness, our year long education and outreach campaign that started in 2004 and done in collaboration with the Dutch Caribbean Nature Alliance, STINAPA Bonaire, and Coral Resource Management was completed. The very successful and well-received campaign focused on sea turtles and provided a year of constant attention through the distribution of newsletters, posters, flyers, buttons, school and community presentations, beach clean-ups and press releases. Our regularly scheduled ‘Sea Turtles of Bonaire’ slide presentation continued to draw the interested public. During the year, we generated a record number of press releases in our effort to bring attention to sea turtle conservation and alert the public to vital issues.

This last year we were able to take a step forward in the organizational arena. Our staff team grew with the addition of Dr. Robert van Dam as our Scientist Coordinator, Eric van der Keuken as our financial advisor and accountant, and a part-time field assistant. Volunteer support and assistance was significantly increased with the addition of three new island residents contributing their time and talents in a consistent fashion. We were also contacted by scores of people offering to assist on an ad-hoc basis.

Our website and electronic newsletters became important and very effective tools for us to share information about the endangered sea turtles and inform about our continuing efforts to protect these animals.

Date
2006
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire

Sea Turtle Conservation Bonaire - Progress Report 2007

We focused our 2007 work on six objectives designed to help us achieve our mission:

  • Science - Improved understanding of sea turtle biology through research in order to guide conservation efforts in benefit of these endangered species.
  • Conservation - Effective management and conservation of Bonaire’s sea turtles and their habitats, resulting in improvements in environmental policy; law and enforcement that ensure conservation and recovery; clean nesting sites; and abundant, high quality foraging habitats.
  • Education and Public Awareness - Increased public awareness of, and concern for, sea turtle conservation, resulting in increased volunteerism and participation in conservation policy, action and advocacy.
  • Training and Collaboration - Provision of training and collaboration opportunities for conservation volunteers and workers that results in increased capacity, locally and throughout the region, for sea turtle conservation efforts.
  • Fund Development - Increased financial investment, both public and private, in support of the protection and recovery of Bonaire’s sea turtle populations.
  • Organizational Development - Development, maintenance, and use of systems and resources that facilitate effective operation of the organization 
Date
2008
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire
Author

Sea Turtle Conservation Bonaire - Progress Report 2008

Our 2008 work plan focused on the following objectives to help us achieve our mission:

  • Science - Improved understanding of sea turtle biology through research in order to guide conservation efforts in benefit of these endangered species.
  • Conservation - Effective management, conservation and advocacy on behalf of Bonaire’s sea turtles and their habitats, resulting in improvements in environmental policy, law and enforcement that ensure conservation and recovery; clean nesting sites; and abundant, high quality foraging habitats.
  • Education and Public Awareness - Increased public awareness of, and concern for, sea turtle conservation, resulting in increased volunteerism and participation in conservation policy, action and advocacy.
  • Training and Collaboration - Provision of training and collaboration opportunities for conservation volunteers and workers that results in increased capacity, locally and throughout the region, for sea turtle conservation efforts.
  • Fund Development - Ongoing public and private financial investment in support of the protection and recovery of Bonaire’s sea turtle populations.
  • Organizational Development - Development, maintenance, and use of systems and resources that facilitate effective operation of the organization. 
Date
2009
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire
Author

Research and Monitoring Report 2010 - Sea Turtle Conservation Bonaire

In 2010, we completed our 8th year of systematic research on the sea turtles of Bonaire. In this report you will read about the methods and results of our sea turtle research and monitoring activities, including nesting beach monitoring, foraging ground surveys, and turtle migration tracking.

Four of the Wider Caribbean’s six species of sea turtles are found in the waters of Bonaire. They are: the hawksbill (Eretmochelys imbracata), the green turtle, (Chelonia mydas), the loggerhead (Caretta caretta), and the leatherback (Dermochelys coriacea). The hawksbill and leatherback are considered “critically endangered” throughout their global ranges; and the green and loggerhead considered “endangered”. Bonaire offers a relatively safe haven for foraging juvenile hawksbill and green turtles, as well as critical nesting grounds for hawksbill, loggerhead, green, and the occasional leatherback. 

Date
2011
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire
Author