Distribution

This one-year pilot project aims to provide an insight in the ecology of Antigonon leptopus (Corallita) an invasive vine, which is overgrowing the native vegetation (Photo 1). This pilot project is just a first step in controlling the Antigonon leptopus. This research was done on a small scale and under controlled circumstances. Our ideas are just for small scale use in town but also to eradicate ‘hotspots’ to prevent further spreading especially near the National Parks. The government with STENAPA as a consultant should take further actions to continue this project and put it as a high priority. The first step was made and we hope this will contribute in containing the species and monitoring the species closely. More research on the life circle and possible natural enemies and its sensitivity for herbicides should be done in order to start a larger scale eradication campaign. The project does not stand on its own, the vine contributes in the prevention of soil erosion on the island. A full size project including replanting/reforestation with native species and renewed agricultural activities should be set up for the long term.

Objectives

• The primary research aim is to reduce and control the growth of Corallita on St. Eustatius and to prevent the species from invading the national parks. In order to achieve this, it is necessary.
• To gather information about the ecology of the species, such as its life cycle, dispersal, germination capacity, use of the species by animals etc. • To gather information about how the species will react on different potential control methods.
• Inform the local community about control methods if usable results are obtained.

Discussion and conclusion

Three weeks after the first treatment at Gallow Bay no regrowth was observed, this means the herbicide does work with smaller concentration (12.5% and 25%) on short term. After six weeks the first regrowth was observed. The tubers are still intact after the first treatment. It is not known how many times the treatment with these concentrations is needed.

In both plots of Sandy Road the plants have regrowth after 7½ weeks. Our observation on 13th January 2007 showed that a lot of Corallita was growing from the border into the plots covering the soil. The treatment did work but probably needed a second treatment if there is regrowth of 30-40cm. Further monitoring of large plots (during one year) is needed to make sure smaller concentrations will kill the plants. Tubers should de dug up and checked on viability. New plots should be selected.

The known moss flora of the small West Indian island Saba (870 m in altitude) consists to date of48 species, while the neighbouring island St. Eustatius (600 m) has 40 species. The two islands have 27 species in common. Widely distributed neotropical species dominate at all elevations, while wide-tropical (i.e. pantropical) species are found mainly at middle elevations (300-600 m). Species with smaller geographical distributions (southern neotropical, Caribbean) are restricted to higher elevations (above 600 m).

An attempt has been made to determine the relation between mosses and the plant communities, encountered along the altitudinal gradient, by calculating “association values”, based on the results of random collecting. Four classes of association values have been distinguished: class A: very characteristic; class B: characteristic; class C: moderately characteristic; and class D: non-characteristic species. It appears that eight plant communities on both islands harbour one or more moderately to very characteristic species. Neckeropsis undulata is the only very characteristic species. It occurs in the evergreen seasonal forest on St. Eustatius. The results are compared with Guadeloupe, Martinique, Puerto Rico, Guyana and Suriname. Finally, a key to the species is included.

Aims: In the marine biological literature sea-grass beds are generally regarded as being more or less similarly structured, and typically indicated as the sea-grass ecosystem. This assumption regarding their structure is discussed and rejected, as regarded on a worldwide scale sea-grass beds show considerable variation in many qualities to be elucidated in this paper. Study area: Sea-grass beds of the world. Methods: A combination of the formation approach and the phytosociological approach is applied, using genera (instead of species) and some structural vegetation characteristics as variables. The study of sea-grass beds with the two mentioned approaches is elucidated, and the history of their application for the classification is outlined. Results: Six well-defined classes of sea-grass communities are recognised on a global scale (top-down). The classification of the sea-grass communities is presented in the form of an identification key. The descriptions are based on floristic composition, physical structure (stratification, rooting system), relation to the substrate (soft substrate or rock), and degree of permanence (from annual presence to millennia). Conclusions: The assumption that sea-grass communities may be considered as more or less similarly structured ecosystems is an unjustified simplification, as the world’s sea-grass beds show, apart from differences in the species composition, considerable variations in their structure, persistence and performance. They have been accepted as a ‘formation’ in its own right. Seagrass communities are well distinguished from all other plant communities, and show only occasionally some overlap with communities of brackish and continental salt waters. Descriptions of sea-grass communities are generally based on the dominant angiosperm component, and thus present in fact only taxo- or merocoenoses. Consequently, they may show considerable regional variations, and even within the same area, if the algal flora, the fauna and environmental parameters, such as exposition to wave action, salinity, and substrate are being considered. The importance of the proposed classification is that comparisons of sea-grass communities can be made at the right level, and that generalisations should be considered in a more critical manner.

The Lesser Antilles are home to four different colubrid snakes of the Alsophis genus. Alsophis used to be common around the Lesser Antilles, but has declined dramatically. The Red-bellied Racer snake (Alsophis rufiventris) is one of those four endemic Alsophis species of the Lesser Antilles. The islands St. Eustatius (Statia), Saba, St. Kitts and Nevis used to be home to A. rufiventris, when in the 1900s A. rufiventris got extirpated on St. Kitts and Nevis. Only two subpopulations exist today, on 10.9% of its original range. Therefore, A. rufiventris is now classified as endangered on the IUCN red list. A better understanding of these animals can help in effectively protecting them. To get an idea of the distribution and dispersion on the trails of the western slope of the Quill was investigated, because the abundancy of A rufiventris was thought to be the highest there.

In total 66 snakes were PIT tagged, over a three month period, of which 34 males and 32 females, suggesting a sex ratio of 50:50. Every snake was measured to see if there was a difference in tail length between males and females, to create an easy, costless and harmless way to distinguish both sexes, other than from the look of the exterior. Males had a significant longer tail, making it possible to use this method to identify the sexes.

Encounters and reencounters were mapped to give an idea about the dispersion of A. rufiventris. There were 43 reencounters, of which 4 snakes where reencountered three times after initial tagging. Different snakes were reencountered several times within a 80 meter range. Only one snake was reencountered about a kilometre from the first three encounters of that individual. Therefore, over this short period A. rufiventris seemed to have a certain home range, though the behaviour of other Alsophis species suggest that they will be rather nomadic over a longer time period. For that reason, long time study is suggested, to learn more about the specific behaviour of this species.

[Student report]

The bat fauna of the Caribbean island of Sint Eustatius consists of five documented species—Monophyllus plethodon, Brachyphylla cavernarum, Artibeus jamaicensis, Ardops nichollsi, and Molossus molossus—and one provisional species—Tadarida brasiliensis. The Insular Single-leaf Bat, M. plethodon, is reported in the scientific literature for the first time from Sint Eustatius based on material presented herein. The bat fauna of the island is considered to be unbalanced because only three species, which are the environmental generalists, are abundant, whereas the more specialized species are rare or absent from the fauna. It is our hypothesis that the unbalanced bat fauna on St. Eustatius is the result of chronic environmental degradation and destruction due primarily to human activity.

In the 1970s, black band disease (BBD) emerged as a mass coral killer and caught the attention of scientists. Although BBD has been studied for more than thirty years, it continues to confound scientists due to the complexity and composition of the bacterial mat which varies among BBD cases. In previous studies, BBD was found in correlation with small environmental changes. Because the distribution of BBD has not been previously documented for Bonaire, I studied its distribution and measured environmental parameters (depth, temperature, pH, phosphate and nitrogen) at six sites. I also recorded the number of BBD incidents on 3 replicate transects, each 10 m 2 in area and 10 m apart at both 15 and 30 feet. BBD was found at Andrea II (both depths), Angel City (both depths) and Jeannie’s Glory (15 ft), but not at Karpata, Captain Don’s, or Yellow Submarine. Informal surveys at other dive sites on Bonaire and Klein Bonaire showed BBD cases at Monk’s Haven, Monte’s Divi, and Handsoff reef, but it was not present at Boca Bartol or Nukove. Most BBD cases were found shallower than 20 feet. I found no statistically significant differences between environmental parameters and observed BBD cases.

This student research was retrieved from Physis: Journal of Marine Science I (Fall 2006)19: 26-32 from CIEE Bonaire.

The marine bearded fireworm, Hermodice carunculata, is a highly mobile polychaete that is abundant on the coral reefs of Bonaire and is active at night. H. carunculata fluoresce brightly facilitating a novel approach to studying their night ecology. The purpose of this research is: 1) to document the ontogenetic fluorescence patterns of H. carunculata using a laboratory study and 2) to determine the depth distribution, habitat use and feeding behavior of H. carunculata of increasing size classes using fluorescence as an ecological tool. There are changes in fluorescence as H. carunculata grow. Polychaetes < 5cm in length fluoresced bright green whereas, worms > 5 cm displayed a banded orange pattern across the dorsum with bright green or blue outlining the dorsal surface of the body. The field study documented that more small and medium H. carunculata were found at shallower depths (2 and 6 m) whereas large H. carunculata were evenly distributed at all 3 depths (2, 6, and 15 m). All size classes were found most often on sand and rubble. Small and medium worms were found on 5 additional substrata. Large worms were found on 2 additional substrata, live and dead coral. Small and medium worms were feeding on decaying matter, algae and sponges whereas, large worms were feeding on live coral. In terms of habitat use and diet, it appears that large H. carunculata (> 3 cm) are more specialized than the smaller size classes (< 1 cm, 1 – 3 cm).

This student research was retrieved from Physis: Journal of Marine Science II (Fall 2007)19: 3-8 from CIEE Bonaire.

Spirobranchus giganteus is a tube-dwelling polychaete more commonly known as the Christmas tree worm. S. giganteus larvae are planktonic, which is followed by benthic settlement and development into a sessile adult. It has been shown that chemical and physical cues produced by live coral and adult S. giganteus attract larvae to settlement sites. In fact, it has been postulated that there may be a mutualistic relationship between S. giganteus and live coral. However, settlement of S. giganteus on coral rubble has been noted in the field. The aim of this study is to investigate whether there is a relationship between size of S. giganteus and substratum settlement type on the coral reefs of Bonaire. The hypothesis under examination in this study states that S. giganteus settled on live coral will be larger than S. giganteus settled on rubble. The measurement chosen for this study was the diameter of the orifice of the calcareous tube, since it has been shown that this is a good estimate for overall size of the polychaete. The diameter of the orifice of S. giganteus was significantly greater for individuals living on rubble (0.510 cm) than individuals living on live coral (0.457 cm). The species of coral that S. giganteus settled on also appeared to affect the orifice diameter. Individuals on Agaricia agaricites were significantly smaller than individuals settled on both Montastrea annularis and Siderastrea siderea. These results may indicate that the interactions between S. giganteus and live coral, such as extracoelenteric digestion and sweeper tentacles, may be disruptive enough to cause a lower size distribution of polychaetes on that substrate when compared to rubble.

This student research was retrieved from Physis: Journal of Marine Science III (Spring 2008)19: 25-30 from CIEE Bonaire.

The spotted moray eel, Gymnothorax moringa, is one of the most abundant moray eels found in the coastal waters of Bonaire, N.A. However, little is known regarding the factors that contribute to its choice of habitat, behavior, and times of activity. Contradictory evidence has been reported for many species of Gymnothorax as to whether they are nocturnal or diurnal, yet little is known concerning color and size, which may be correlated to diet and choice of habitat. This study sought to determine how size, behavior, and color correlate with reef flat and reef slope habitats and at what time (morning or evening) G. moringa is most active. Observations of G. moringa were conducted in the westward coastal waters of Bonaire. A “U”-shaped search pattern was utilized in locating spotted moray eels in 5 adjacent study areas extending perpendicular from the shore to a depth of ~ 15 m. Once an individual was located behavior, jaw size, and color, were recorded in order to assess differences among individuals on differing habitats (reef flat or reef slope), and times of day (morning: 6:00 - 7:30 or evening: 18:00 – 19:30). G. moringa was found to be in greater abundance on the reef flat in the evening displaying exposed venting behavior and individuals were predominantly white in coloration. In the morning G. moringa were found to be in greater densities on the reef slope, displaying foraging behavior, and were predominantly black in coloration. Representatives of all size classes were distributed on the reef flat regardless of time, however, small individuals were not observed on the reef slope in the evening.

This student research was retrieved from Physis: Journal of Marine Science VI (Fall 2009)19: 7-13 from CIEE Bonaire.

Cleaning is a symbiotic behavior that has been observed in many animals, including both terrestrial and marine species. Cleaner species and their cleaning stations play a vital role in coral reef ecosystems by removing parasites, mucus, and diseased or dead tissues from their client fish. In this study, the depth distribution of cleaning stations and the interactions between cleaner and client species were observed with respect to three of the most prominent cleaner species in the Caribbean: juvenile Bodianus rufus (Spanish hogfish), Elacatinus evelynae (Sharknose goby), and Anclyomenes pedersoni (Pederson‟s cleaning shrimp). Research dives were conducted at Yellow Sub dive site on the leeward or west coast of Bonaire, D.C., a small island in the southern Caribbean off the coast of Venezuela. Two dives were conducted ad libitum, with observers recording all cleaning stations between 20 and 50 ft to determine the distribution of the three cleaning species. Observations on cleaner-client interactions were collected at several shallow stations on ten subsequent dives. Cleaner-client interactions at each station were categorized as inspected and cleaned, ignored, jolted, and scared away by another fish. Data analysis indicates that B. rufus, E. evelynae, and A. pedersoni do not have different depth distributions, but they all show the highest abundance of stations between 20 and 30 ft. The four cleaner-client interactions varied by both cleaner and client species. It is important to better understand the role of cleaning stations in coral reef ecosystems, as they are known to positively affect fish richness and diversity.

This student research was retrieved from Physis: Journal of Marine Science XII (Fall 2012)19: 91-100 from CIEE Bonaire.