Species

Abstract:

In December 2012 IMARES conducted workshops on the identification of whales & dolphins in the Caribbean on the islands of Sint Maarten, Saba and Sint Eustatius. Apart from giving the workshops, on-going cetacean projects, future monitoring needs and possibilities for extending monitoring projects were discussed together with the staff of the marine parks, government representatives and other local stakeholders, as well as with international research groups active in the Caribbean.

This report gives an overview of the occurrence of cetaceans in Saba, Sint Eustatius and Sint Maarten and describes the results of the cetacean identification workshops and the considerations with the local stakeholders. It also provides examples of existing on-going monitoring projects and an overview of research approaches that could be implemented on a local scale, or on a larger (national and international) scale in the future.

Management Recommendations:

Define monitoring need
There is a strong need to define what kind of monitoring is needed for both the near-shore areas (e.g. marine parks) and offshore areas (e.g. EEZ, trans-boundary regions). The best type of monitoring depends on the scale (Marine parks vs EEZ vs Wider Caribbean), the aims (e.g. long- term monitoring; estimation of abundance, biodiversity or distribution; risk assessment and conservation) and the available funding.

Coordinate and streamline current efforts
On a local scale cetacean monitoring has already started on the islands in different ways. The efforts range from the collection of any sightings made from land and water, to conducting effort related surveys in near shore waters. Some of these programs could be extended and coordinated between the islands. However, it is unlikely that the current staff would be able to do more than they are doing at the moment as they either need to have more staff or get long term assistance in the collection and analyses of the data.
A standardization of monitoring approaches between the different islands and the development and use of a common database would be helpful to allow the direct comparison of data. The new project idea to use handheld hydrophones on all three islands to monitor cetacean presence is a promising approach. However, close cooperation between local staff and IMARES and some long term funding is needed to ensure useful results will be obtained in the long run.

Extend monitoring efforts to a larger scale
Several people of the local staff of all three islands have been involved in the French AGOA surveys. This has provided them with more knowledge on cetaceans in the area, insights in data collection methodology and has also provided data for the Dutch Caribbean waters on the occurrence of cetaceans. The current protocols of the AGOA could be adapted and expanded to better fit the needs (to be defined) of monitoring cetaceans in Dutch Caribbean waters. A standard protocol for all areas could be a first step for a common database which could then be analysed on a regular basis. Following a similar survey protocol one could extend the AGOA survey in Dutch waters.
To obtain absolute abundance estimates of cetaceans in the EEZs of Saba and Sint Maarten, it is necessary to conduct designated surveys in the Dutch Caribbean waters using survey vessels or airplanes.

Risk assessment
In order to achieve an adequate conservation of the marine mammals in the Dutch Caribbean, information on species composition, distribution and abundance should be used for an assessment of the existing and potential threats to these cetaceans. 

This report is part of the Wageningen University BO research program (BO-11-011.05-005) and has been financed by the Ministry of Economic Affairs, Agriculture and Innovation (EZ) under project number 4308201083. 

Abstract:

With the new status of special municipality Bonaire’s development aims have focused toward more efficient  sustainable policies. With centuries of human intervention, ecosystem degradation, pressure of invasive species and tourism industry, services associated with biodiversity are threatened by developmental needs. The Amazona barbadensis parrot is of special conservation concern due to the vulnerability to habitat degradation and poaching and its small range restricted to Bonaire and Northern Venezuela. We ask whether the spatial development plan of Bonaire (ROB) for the coming years has an either positive or negative effect on the parrot population in the island. We used METAPHOR, an individual-based stochastic population model in order to estimate the population trend for the next 200 years. We use two cases, poaching and no poaching, and four scenarios, Current, two scenarios contemplated in the ROB and one scenario of goat control and vegetation recovery that changes nest availability.For all the scenarios the model showed great stability around the year 100.Reducing poaching and controlling goats increased the population in each scenario with c. 50%. The ROB scenarios did not increase the population size or made it significantly lower, as only the (minor) impact on carrying capacity was taken into account. The estimated population size under current conditions was ~1800. Increasing poaching to 50% diminished this valued until 1000 while the poaching didn’t affect the age structure. Increasing availability of nests to 130 raised the population to 3000. The used survival of 87% for fledges and adults showed to be the most optimistic case in the sensitivity analysis warning about the real status of the population and the high uncertainty of the model. The control of the invasive goats has been a conservation success in other islands and showed to have the best outcome for the modelled population. Whether it is control of goats or vegetation restoration, increasing vegetation cover would favour conservationist and economic aims providing habitat for plant and animal communities and  providing more valuable services for terrestrial ecotourism.

Abstract:

The Atlantic and Gulf Rapid Reef Assessment (AGRRA) sampling strategy is designed to collect both descriptive and quantitative information for a large number of reef vitality indicators over large spatial scales. AGRRA assessments conducted between 1998 and 2000 across a spectrum of western Atlantic reefs with different histories of disturbance, environmental conditions, and fishing pressure were examined to reveal means and variances for 15 indicators. Twenty surveys were compiled into a database containing a total of 302 benthic sites (249 deep, 53 shallow), 2,337 benthic transects, 14,000 quadrats, 22,553 stony corals. Seventeen surveys contained comparable fish data for a total of 247 fish sites (206 deep, 41 shallow), 2,488 fish transects, and 71,102 fishes. Shallow (≤ 5 m) reefs were dominated by A. palmata, a good proportion of which was standing dead, while deep (>5m) reefs were nearly always dominated by the Montastraea annularis species complex. Fish communities were dominated by acanthurids and scarids with seranids making up less than 1% of the fish seen on shallow reefs and 4% on deep reefs.

AGRRA benthic and fish indicators on deep reefs showed the highest variation at the smallest spatial scale (~<0.1 km), with recent mortality and macroalgal canopy height displaying the largest area and subregional scale (~1-100 km) variation. A mean live coral cover of 26% for the 20 survey areas was determined for the deep sites. Significant bleaching and disease-induced mortality of stony corals associated with the 1998 (El Niño-Southern Oscillation) ENSO event were most apparent in the western Caribbean and Bahamas subregions and the Montastraea annularis complex was the most heavily impacted.

The overall low number of sightings for larger-bodied groupers and snappers (~< 1/100 m2) as a whole suggest that the entire region is overfished for many of these more heavily targeted species. More remote reefs showed as much evidence of reef degradation as reefs more proximal to human coastal development. Characterizing present-day reef condition across the region is a complex problem since there are likely multiple sources of stress operating over several spatial and temporal scales. Not withstanding the many limitations of this analysis, the value of making multiple observations across multiple spatial scales that can approximate the “normal” state for the region today is still very high. 

The literature on the endemic flora and fauna of the Dutch Lesser Antilles is scattered and often difficult to find. An initial compilation amounts to 163 extant terrestrial and freshwater taxa (121 nominate species and 42 subspecies) and 58 marine taxa (all nominate species) which are either restricted to one or more of the ABC islands, or which otherwise have a limited geographical distribution in the Southern Caribbean (i.e. endemic). In addition, a total of 39 endemic fossil taxa are listed.

The breakdown for extant endemic terrestrial and freshwater species and subspecies is as follows: plants (22 sp.); arachnids and insects (40 sp. + 4 ssp.); freshwater and subterranean crustaceans (25 sp. + 3 ssp.); freshwater polycheats, flatworms, rotatoria (7 sp.); terrestrial gastropods (15 sp. + 5 ssp.); fresh- brackishwater fishes (2 sp. + 1 ssp.); reptiles (9 sp. + 3 ssp.); birds (22 ssp.); 4 mammals (1 sp. + 4 ssp.).

Marine endemism especially concerns marine gastropod mollusks, many of which show direct development or have short larval dispersive stages. Other marine taxa probably contain significant endemism as well but have not been included because of a lack of information.