Debrot, A.O.

Luxuriant fringing reefs along the southwestern shores of the Caribbean islands of Curaçao and Bonaire (12°N), located outside the most frequent hurricane tracks, are rarely affected by major storms. Consequently, reef growth and long‐term preservation are potentially optimal and distinct from reefs experiencing greater hurricane frequency. Hurricane Lenny (November 1999) took an unusual west‐to‐east track, bisecting the Caribbean Basin north of these islands, but generated heavy waves (3‐6 m) that severely damaged reefs along the normally leeward shores. Massive coral colonies >100 years old were toppled, but even at the most severely damaged sites, 82–85% of colonies remained in growth position. Late Pleistocene (125 ka) elevated reefs in the Lower Terrace of Curaçao record even higher proportions of corals in growth position (93%), possibly reflecting a low hurricane frequency during the Pleistocene highstand. In comparison, coeval Pleistocene reefs in regions that today experience a high hurricane frequency (Great Inagua Island and San Salvador, Bahamas) have lower proportions of corals preserved in growth position (79% and 38%, respectively). These results are consistent with the hypothesis that reefs in regions experiencing very low hurricane frequency, like the southern Caribbean, are more likely to be preserved with corals in primary growth position in comparison to regions with higher hurricane frequency.

Fringing reefs along the southwestern shores of the Caribbean islands of Curaçao and Bonaire (12°N), located outside the most frequent hurricane tracks, are rarely affected by heavy wave-action and major storms, yet have experienced disturbances such as coral bleaching, coral diseases, and mass mortalities. The last major hurricane to hit these islands occurred over 100 yr ago. In November 1999, Hurricane Lenny took an unusual west-to-east track, bisecting the Caribbean Basin and passing approximately 200 miles north of Curaçao and Bonaire. The leeward shores of both islands were pounded for 24 h by heavy waves (~3–6 m) generated while the storm was centered far to the west. Reef damage surveys at 33 sites conducted between November 1999 to April 2000, following the storm, documented occurrences of toppling, fragmentation, tissue damage, bleaching, and smothering due to the storm. Reefs were severely damaged along westward-facing shores but less impacted where the reef front was tangential to the wave direction or was protected by offshore islands. At the most severely damaged sites, massive coral colonies 2–3-m high (older than 100 yr) were toppled or overturned, smaller corals were broken loose and tumbled across the shallow reef platform and either deposited on the shore or dropped onto the deeper forereef slope. Branching and plating growth forms suffered more damage than massive species and large colonies experienced greater damage than small colonies. Toppled massive corals have a high potential of preserving the event signature even if they survive and continue to grow. Reorientation of large, long-lived coralla may provide a unique indicator of disturbance in a reef system rarely affected by hurricanes. At some locations, wave scouring removed loose sediment to reveal a cemented framework of Acropora cervicornis rubble on the shallow platform above 10-m depth. This rubble was generated in situ, not by storm processes, but rather by an earlier mass mortality of thickets of staghorn coral that covered extensive areas of the shallow platform prior to the incidence of white band disease in the early 1980s.

This report describes the possible Outstanding Universal Value of the potential World Heritage nomination that combines the Bonaire National Marine Park (BBNMP)) and the Curaçao Marine Park (CC MP ) from the ecological , geological and biodiversity perspective. According to World Heritage natural criteria, these correspond to criteria (vvii)) (aesthetic and spectacular natural phenomena)) , (vviii)) (ggeological and geomorphific processes)) , ( ix ) (ecological and biological processes)) , and ( x ) (biodiversity)) , as defined by the Operational Guidelines for the Implementation of the World Heritage Convention (UUNESCO 2017).

Based on expert advice to expand the size of the initial proposed nomination, which only included BNM,, and recent policy action towards reinforced management implementation of the Curaçao Underwater Park , the Curaçao Underwater Park is considered to be a necessary addition to expand the total area for the nomination. This expansion intends to strengthen the Outstanding Universal Values (OOUV) for a successful UNESCO World Heritage bid. We here document the OUV of the proposed nomination by combining the Bonaire National Marine Park and the Curaçao Underwater Park for a single nominatio , known as a serial site with two components,, herein referred to as the Bonaire and Curaçao Marine Parks (BBCMP). This report also highlights the benefits of and opportunities for f urther strengthening the OUV: by 1)) extending the bo undaries of the two MPAs – landward and seaward, and 2) considering additional areas that include wetlands, pelagic areas and deep benthic habitat. Such an expansion would benefit 1)) the geological values by encompassing examples of visible geological hist ory (ccriteria ( viii )); 2) the ecological values by including different habitats forming part of the connectivity continuum (criteria ( ix ); and the biodiversity and conservation values by including a larger number of endemic and threatened species and their key life-cycle stages (ccriteria ( x ) ).. In this report the additional areas are considered as part of the buffer zone,, as local authoriti es need to consider the feasibility of legal protection and management for a larger area.. Many of the values discussed in this report face important threats and have suffered documented declines in recent decades. This report does not address those issues or discuss possible management measures but only focusses on the values present and how these might contribute to potential OUV.   

Report by CARMABI

Natuur-en cultuurhistorische waarden van plantage Onima, Bonaire

The Yarari Marine Mammal Sanctuary (hereafter simply referred to as the Yarari Sanctuary, or Yarari) was formally established on September 2, 2015. It is currently composed of two sectors: one surrounding Saba and the Saba Bank and one covering the EEZ waters of Bonaire. In order to help establish an effective cetacean conservation management plan for the Saba and Saba Bank sector of the sanctuary we here review the main marine mammal threats, help identify main management goals and make both governance and management recommendations based both on stakeholder interviews and a management review of functioning marine mammal sanctuaries in the Western Atlantic.

There are 8 species of marine mammals known to occur in the windward Dutch Caribbean Yarari Sanctuary. The sanctuary has relatively low levels of human activity. Based on our review, cumulative contaminant impacts – such as oil contamination originating from St. Eustatius – are potentially highest, followed by collision impacts due to the relatively high level of shipping traffic. Other factors such as, fishery entanglement, bycatch-impacts and marine debris impacts are likely low compared to many areas directly outside the sanctuary. While whale & dolphin watching impacts are still probably negligible, the impacts of anthropogenic noise, climate-change impacts and cumulative impacts still remain unknown but are potentially high.

Five main clusters of interrelated goals and objectives were identified based on expert and management stakeholder interviews. The most essential proximate goal for management should be to establish a minimum structural level of institutional capacity. Under the reigning conditions of resource limitation, the next key goal should be to establish effective collaboration towards jointly achieving the higher management goals and objectives.

Based on our review of species, threats, operations of other sanctuaries and expert and stakeholder input we list 23 priority recommendations and action points towards implementation of cetacean conservation for the Saba and Saba Bank Yarari sector. 

           Governance

• Use the Saba Bank Management Unit (SMBU) governance model for Yarari management

  implementation.

• Consider merging Yarari tasks into the SMBU to effectuate resource pooling and prevent

  management fragmentation.

• Legal resources
• Design and implement a simple legal mandate for Yarari management.
• Copy and implement international legal guidelines for whale watching.
• Revise the Fishery Framework Act BES (Vissery Visserijwet besluit BES) or draft a Decree

  (Regeling) under the Nature Conservation Framework Act BES (Wet Grondslagen Natuurbeheer en-bescherming, WGN) to forbid all forms of pelagic (not benthic) longline and purse seine fishing in Yarari waters.

• Devise and implement legal measures and guidelines to safeguard Yarari from anthropogenic noise pollution.
• Finances
• Based on the review of functioning sanctuaries, and current stressor levels, a basic annual budget of US$ 150 K will be sufficient to implement satisfactory marine mammal conservation.
• Focus expenditures on management development, outreach and international cooperation.
• Limit expenditures on costly enforcement and research. Participation in these activities should principally be limited to essential monitoring and practical support of collaborating parties. 

           Personnel and logistics

• Based on the review of functioning sanctuaries, two (additional) personnel members are

  sufficient to effectuate adequate Yarari cetacean conservation.

• The combined personnel should include both technical and boat handling skills as well as

  management development skills for effective local and international policy development

  support and cooperation.

• Saba island is the logical choice for basing Yarari headquarters.
• A larger vessel (than the current Queen Beatrix) is needed for safer and more effective

  operation in Yarari waters.

  Management priorities

• Aim for sanctuary expansion to include St. Maarten and St. Eustatius marine waters (and

  ultimately also Curaçao and Aruba EEZ waters).

• Establish and expand cooperation with local enforcement and research partners.
• Develop close ties with local stakeholders and encourage their active involvement.
• Actively represent Yarari interests in regional marine mammal policy development and

  research initiatives.

  Research priorities

• Use remote methods (AIS) and current port fishery sampling to monitor fishery activity, and

  ship traffic inside Yarari.

• Use passive acoustic monitoring and sighting records to monitor cetacean distribution and

  abundance.

• Use passive acoustic monitoring to measure and follow background noise levels.
• Record and collect data on and specimens from stranding incidents using published guidelines

  and protocols.

• Subsample stranding fatalities to determine contaminant loads of the cetaceans inside Yarari

  and their prey species.

• Document the abundance and source of marine debris found in the sanctuary. 

Foreword

Butterflies are a colorful and fascinating group of insects that have attracted a great deal of interest from naturalists in the past. In Curaçao, Aruba and Bonaire they can be easily observed by both young and old, whether in the city or in the countryside. Yet, most people remain totally unaware of the many colorful species that can be seen and very little is known about the local occurrence and habits of these insects.

This booklet is a popular picture guide to the butterflies of the Leeward Dutch Antilles, brimming with colorful pictures and written with a succinct, easy-to-follow text. In light of the ever growing interest in the wildlife of our islands, this book fulfills a clear need for palatable information on a much neglected part of our fauna. Reading through the booklet, from page to page, one cannot but remain impressed by the large variety of colors and patterns displayed by our butterflies.

The information presented, demonstrates the overriding dependence of the butterflies on native plants as opposed to introduced plants. A large number of native species are largely restricted to natural woodlands and many are rare. The situation for many but- terflies on Bonaire and Aruba is much more critical than on Curaçao. To preserve our butterflies for the generations to come, natural woodlands must be effectively protected and, wherever possible, native plants should be given preference over introduced plants.

There can be little doubt that this issue will contribute to a greater appreciation of the animal life of our islands. Hopefully it will also contribute to a more responsible attitude towards nature. The Carmabi Foundation has been on the forefront of natural sciences and nature conservation in the Dutch Leeward Islands for five decades now. Over the years the institute has brought forth hundreds of scientific contributions and scholarly books on the natural resources of these islands. I hereby congratulate the authors and the foundation with yet another beautiful contribution to the natural history of our islands. 

Following climate change, IAS are recognised as the second-most serious long-term threat to island ecology, worldwide. Of all IAS issues, by far the most serious is the problem of roaming livestock. On most islands this concerns the eubiquitous domestic goat. 

In addition to major inventories of invasive species (see the first 4 reports below) and the development of a joint strategy, as part of the Wageningen BO research program, IMARES has also led the way to several pilot-scale interventions, in close cooperation with island partners. Current studies include work to document the positive effect of feral cat control on survival of endangered ground-nesting seabirds in Saba, control and eradication of the Giant African Landsnail on Statia and control of goat grazing inside the Washington Slagbaai park in Bonaire. Within the European Netherlands, IAS are also recognized as a key scourge to both nature and economy and in 2015 stringent new legislation was implemented not only in the Netherlands, but throughout the EU. See below, for a full listing of IMARES recent work in this area of concern.

The problem of roaming livestock is particularly acute in the Caribbean Netherlands. It is a major impediment to agricultural development and nature conservation on St. Eustatius, as it also typically is on other islands in the region. In support of a government-led culling program, we here conducted a baseline study of livestock abundance and distribution on the island in the final quarter of 2013. In doing so we provide the first quantitative assessment of livestock densities ever in the Dutch Caribbean.

Five of the largest remaining patches of livestock-inaccessible rock vegetation of Curacao, Netherlands Antilles, were described and compared to rock vegetation which has experienced centuries of livestock grazing. Study rocks (maximum diameters: 20-47 m) were located at two sites differing in rock type and altitude. At the St. Christoffelberg site, study rocks were siliceous and at altitudes of 240-310 m while at the Tafelberg site the rocks were of limestone and at altitudes of 35-150 m. The main vascular species on livestock-inaccessible rocks at both sites was Tillandsia flexuosa. a bromeliad. At the St. Christoffelberg, Tillandsia was principally accompanied by the grass Paspalum secans, the orchid Brassavola nodosa and the herb Portulaca venezuelensis, while at the Tafelberg it was principally accompanied by the vine Serjania curassavica. On livestock-accessible rocks Tillandsia ground cover was reduced to insignificant levels and mature plants were virtually eliminated from the population. Grazed vegetations also showed reduced vascular cover and were principally dominated by the annual grass Aristida adscencionis (St. Christoffelberg site only), the prickly pear Opuntia wentiana and the shrubby tree Acacia tortuosa. None of these weedy species, all of which are widely distributed on the island, were of any significance in ungrazed rock vegetations. It is hypothesized that Tillandsia-dominated ground cover may have been a common feature of the rock vegetation of the island prior to the introduction of livestock.

One of the most deleterious invasive introduced predators worldwide is the domestic cat which has been found responsible for many island extinctions worldwide. Cats can live off both natural prey and garbage and can be a particularly serious threat to ground-nesting bird populations. Saba is an important location for the Red-billed Tropicbird, Phaethon aethereus and feral cats are thought to be the main reason for the low breeding success in the southern coastal colonies of this bird.

To make proper decisions in invasive predator management, information is needed on the effects of cat removal on the tropicbird breeding success and the possible resulting increase in egg predation by rats in the case of any “mesopredator release effects”. In this study we collected the first season of data needed to assess the effect of cat removal on the breeding success of the tropicbird on Saba. Two tropicbird nesting colonies (Great Level and Tent) were monitored in terms of egg and chick predation, under different net cat-removal intensities and the resulting survival was compared to survival prior to cat removal (as documented elsewhere).

In total, Saba Conservation Foundation removed 19 cats from the entire study area, of which eleven adult cats were removed from the Great Level colony and only six adult cats and two kittens were removed from the Tent colony. The gut contents of the 17 of these 19 feral cats consisted of natural prey (grasshoppers, rats, chickens, anoles and crickets), bait placed in the trap or even plant material. In the previous season 18 cats had already been removed (12 trapped, 6 shot) from the Great Level area.

During the period of September 2013 to May 2014, 46 occupied tropicbird nests were monitored, 27 at Tent, 15 at Great Level and 4 at Fort Bay. Fort Bay was not used in the data analysis. Egg-laying was documented in 34 of these nests. Observed egg failures were due to a variety of causes such as failure to hatch , broken eggs, including the breaking of an egg by an adult, and the disappearance of the whole nest due to heavy rainfall. Egg survival did not show a significant difference between the two colonies. In total 23 chicks were born, of which at least 15 died. Chick survival did show a significant difference between the two colonies, whereas prior to cat removal both had had zero chick survival. The breeding success of the tropicbirds and percentage of chicks fledged did appear to increase encouragingly in the breeding colony where cats had been more intensely culled (Great Level; 28 of initial 35 adult cats removed during two trapping seasons). The success on Great Level is notable, because in the breeding season of 2011/2012 the breeding success had been zero percent for several years.

Around the Tent colony only six adult cats were removed this season (total of 7 removed during two trapping seasons), which was insufficient to effectively increase breeding success in the tropicbird. A comparison of camera-trap densities showed that effective cat density at Tent by the end of trapping remained 4-5 times higher than at Great Level where 28 of the initial 35 adult cats had been removed. In total four black rats were observed on the camera traps but only appeared to be scavenging and no active egg predation was observed. These preliminary results suggest that cat removal seems to improve fledgling survival at no appreciable expense in terms of egg predation and that risks of any hypothetical “mesopredator release effects” are limited. Due to the low sample sizes in this first season, and natural fluctuations in breeding success which are normal in seabirds, clearly happenstance or other causative factors could equally explain the results obtained. Therefore, more definitive conclusions will depend on a more extensive and multi-year effort. 

Key recommendations:

• Continue with and expand feral cat removal from the main tropicbird nesting colonies.
• Simultaneously monitor nesting success and fledgling survival to develop a more robust data set over a longer time-frame. With an expanded sample size, the benefits in terms of net fledgling survival and any risks of potential “mesopredator release effects” can be more firmly assessed.
• Many cats were documented to be wary of traps. Trapping was also very labour-intensive and entailed both trapping and handling stress. For these reasons additional, more effective yet humane methods (such as predator baiting or shooting) should be used. These methods have proven to be key to effective control of invasive predators worldwide.
• As long as legislation and control of cat importation, keeping and sterilization remain less than strictly implemented and failsafe solutions remain wanting, we recommend to focus removal efforts towards key tropicbird nesting colonies shortly before or during the main nesting season each year.

  This research was funded as part of the Wageningen University BO research program (BO-11-011. 05- 029) under project number 4308701028 (A Debrot, PI). 

Herbebossen in een droog, zonovergoten en zout klimaat, kan dat wel? Ja, zolang je maar slim samenwerkt met de natuur. De vernietigende werking van loslopend vee op de inheemse plantengemeenschappen van droge tropische eilanden is vaak aangetoond. Het goede nieuws is dat met de juiste maatregelen de inheemse ora en fauna een behoorlijke veerkracht kunnen vertonen. Op basis van zeventien jaar ervaring en projecten op meer dan vijftien locaties wordt het hoe hieronder uit de doeken gedaan.