Conservation

A quantitative assessment of the vegetation types on the island of St. Eustatius, Dutch Caribbean

Caribbean dry forests are among the most endangered tropical ecosystems on earth. Several studies exist on their floristic composition and their recovery after natural or man-made disturbances, but little is known on the small Dutch Caribbean islands. In this study, we present quantitative data on plant species richness and abundance on St. Eustatius, one of the smallest islands of the Lesser Antilles. We collected and identified trees, shrubs, lianas and herbs in 11 plots of 25 x 25 m in different vegetation types. We compared their floristic composition and structure to vegetation surveys from roughly the same locations in the 1990s and 1950s. We found substantial differences among our 11 plots: vegetation types varied from evergreen forests to deciduous shrubland and open woodland. The number of tree species ≥10≥10 cm DBH ranged between one and 17, and their density between three and 82 per plot. In spite that all plots were subject to grazing by free roaming cattle, canopy height and floristic diversity have increased in the last decades. Invasive species are present in the open vegetation types, but not under (partly) closed canopy. Comparison with the earlier surveys showed that the decline of agriculture and conservation efforts resulted in the regeneration of dry forests between the 1950s and 2015. This process has also been reported from nearby islands and offers good opportunities for the future conservation of Caribbean dry forests.

Date
2016
Data type
Scientific article
Theme
Research and monitoring
Geographic location
St. Eustatius

Sand temperatures for nesting sea turtles in the Caribbean: Implications for hatchling sex ratios in the face of climate change

A 200-year time series of incubation temperatures and primary sex ratios for green (Chelonia mydas), hawksbill (Eretmochelys imbricata) and leatherback (Dermochelys coriacea) sea turtles nesting in St. Eustatius (North East Caribbean)was created by combining sand temperature measurementswith historical and current environmental data and climate projections. Rainfall and spring tides were important because they cooled the sand and lowered incubation temperatures. Mean annual sand temperatures are currently 31.0 °C (SD = 1.6) at the nesting beach but show seasonality, with lower temperatures (29.1–29.6 °C) during January–March and warmer temperatures (31.9–33.3 °C) in June–August. Results suggest that all three species have had female-biased hatchling production for the past decades with less than 15.5%, 36.0%, and 23.7% males produced every year for greens, hawksbills and leatherbacks respectively since the late nineteenth century. Global warming will exacerbate this female-skew. For example, projections indicate that only 2.4% of green turtle hatchlings will be males by 2030, 1.0% by 2060, and 0.4% by 2090. On the other hand, future changes to nesting phenology have the potential to mitigate the extent of feminisation. In the absence of such phenological changes, management strategies to artificially lower incubation temperatures by shading nests or relocating nest clutches to deeper depths may be the only way to prevent the localised extinction of these turtle populations. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Geographic location
St. Eustatius

Reef flattening effects on total richness and species responses in the Caribbean

1. There has been ongoing flattening of Caribbean coral reefs with the loss of habitat having severe implications for these systems. Complexity and its structural components are important to fish species richness and community composition, but little is known about its role for other taxa or species-specific responses. 2. This study reveals the importance of reef habitat complexity and structural components to different taxa of macrofauna, total species richness, and individual coral and fish species in the Caribbean. 3. Species presence and richness of different taxa were visually quantified in one hundred 25-m2 plots in three marine reserves in the Caribbean. Sampling was evenly distributed across five levels of visually estimated reef complexity, with five structural components also recorded: the number of corals, number of large corals, slope angle, maximum sponge and maximum octocoral height. Taking advantage of natural heterogeneity in structural complexity within a particular coral reef habitat (Orbicella reefs) and discrete environmental envelope, thus minimizing other sources of variability, the relative importance of reef complexity and structural components was quantified for different taxa and individual fish and coral species on Caribbean coral reefs using boosted regression trees (BRTs). 4. Boosted regression tree models performed very well when explaining variability in total (823%), coral (806%) and fish species richness (773%), for which the greatest declines in richness occurred below intermediate reef complexity levels. Complexity accounted for very little of the variability in octocorals, sponges, arthropods, annelids or anemones. BRTs revealed species-specific variability and importance for reef complexity and structural components. Coral and fish species occupancy generally declined at low complexity levels, with the exception of two coral species (Pseudodiploria strigosa and Porites divaricata) and four fish species (Halichoeres bivittatus, H. maculipinna, Malacoctenus triangulatus and Stegastes partitus) more common at lower reef complexity levels. A significant interaction between country and reef complexity revealed a non-additive decline in species richness in areas of low complexity and the reserve in Puerto Rico. 5. Flattening of Caribbean coral reefs will result in substantial species losses, with few winners. Individual structural components have considerable value to different species, and their loss may have profound impacts on population responses of coral and fish due to identity effects of key species, which underpin population richness and resilience and may affect essential ecosystem processes and services.

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Bonaire
Image
Highly complex reef at Bonaire

Establishing a marine conservation baseline for the insular Caribbean

Abstract

Marine protected areas are a primary strategy for the conservation of marine habitats and species across the globe. In small island developing states, they often exceed their terrestrial counterparts in both number and area. To assess their effectiveness as a conservation measure over time, the accurate and up- to-date representation of marine protected areas through spatial and tabular data is imperative in order to establish baselines. Various regional and global agreements have set specific protection targets and these require spatial reporting on protected areas as an indicator of progress. For the insular Caribbean region, this study considers progress towards global Aichi Target 11 of the Convention on Biological Diversity which is to conserve at least 10% of coastal and marine areas, and progress towards the regional target of the Caribbean Challenge Initiative (CCI) to protect “at least 20% of nearshore marine and coastal habitats”, both aiming for a 2020 deadline. Progress towards these targets differs widely depending on the accuracy of the datasets and the methods used. In an effort to update the current baseline of protection within the insular Caribbean, multiple governments, the Nature Conservancy and the Caribbean Marine Protected Area Management Network and Forum collaborated to develop a single insular Caribbean protected area dataset with accurate boundary information and the best available ecoregional and political boundaries. This study represents the most in-depth and spatially accurate effort to date to determine marine protected area coverage in the insular Caribbean. It is found that some form of marine management has been designated for around 7.1% of our study area in the insular Caribbean; progress towards Aichi Target 11 averaged among sovereign states within the insular Caribbean stands at approximately 3.25% and only three of the 10 participating governments in the CCI have reached their 20% target. Ocean protection was further assessed across the 25 governments and the three marine ecoregions by four different marine zones. Recommendations are made on regional to global cooperation for data sharing and reporting on indicators, highlighting possible directions to fill marine conservation gaps in the insular Caribbean. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Saba
St. Eustatius
St. Maarten

The Aruba Island rattlesnake Crotalus unicolor Species Survival Plan: a case history in ex situ and in situ conservation

Established in 1982, the Aruba Island rattlesnake Crotalus unicolor Species Survival Plan (SSP) is the longest continual functioning snake conservation effort of the Association of Zoos & Aquariums (AZA). The captive population has been maintained as an assurance population for the most threatened snake on Aruba. Over the last 26 years, 27 potential founders were imported for assimilation into the SSP to maintain genetic diversity. By 2014, the gene diversity in the captive population was over 94%. In 1986, the SSP began working in partner- ship with Arubans to aid the conservation of the rattle- snake and its ecosystem on the Island. This in situ programme has included ecological research, training, management recommendations, capacity building, workshops, public relations and education. These efforts have been integrated into a holistic long-term project that has resulted in many significant conservation suc- cesses. The extensive efforts made by the AZA and SSP to ensure the continued survival of C. unicolor are a model for zoo-based conservation efforts involving reptiles. 

Date
2015
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Aruba

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 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

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