Distribution

Tubastraea coccinea: Distribution and substratum preference of an exotic coral in Bonaire, Dutch Caribbean

The study of introduced species has gained popularity in recent years. A species introduced to a new area can have negative effects on the native ecosystems, as well as positive interactions with local fauna. The success of an exotic species depends on many factors. Those that are most successful at expanding possess mechanisms of reproduction, settlement, and distribution that aid in competing for space and resources. Tubastraea coccinea, also known as orange cup coral, is native to the Indo-Pacific and was introduced in Bonaire in the 1940s. Little is known about the effects T. coccinea has on the local marine community. It has a very opportunistic nature and has become a dominant scleractinian coral in the subtidal zones occupying shallow, heavy surged waters. T. coccinea is an azooxanthellate coral, which explains its ability to occupy habitats not desirable by other corals requiring sufficient nutrients and sunlight for photosynthesis. The purpose of this investigation was to determine the distribution and abundance of T. coccinea along various sites in Bonaire and observe its habitat preferences. Six sites in Kralendijk, Bonaire were surveyed by snorkelers, who counted various sized colonies and substratum occupancy. T. coccinea was found at all six surveyed sites, being most abundant at sites with very shallow shores and heavy surge. It preferred man-made pilings underneath docks as its habitat. This confirms that T. coccinea is established in Bonaire. By observing the distribution and preferences, the successful nature of T. coccinea throughout the Caribbean can be better understood.

This student research was retrieved from Physis: Journal of Marine Science XIII (Spring 2013)19: 10-16 from CIEE Bonaire.

Date
2013
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

Distribution, substrate preference and possible host benefits of the tropical polychaete Spirobranchus giganteus on a reef in Bonaire

The Christmas Tree worm, Spirobranchus giganteus, is a sessile polychaete found on coral reefs worldwide. Its larvae display photopositive behavior and use chemicals excreted from live coral as a settlement cue. After settlement, the worm grows in concert with the coral for the remainder of its life. S. giganteus displays variable preference for corals as substrate worldwide. It has been shown that the presence of S. giganteus on corals can lessen the effects of disease and coral bleaching on polyps surrounding the worm’s tube, as well as lessening predation by certain corallivores. Due to its potential to maintain healthy corals, it is important to learn more about the ecological role and distribution of S. giganteus. This study aimed to determine at what depth S. giganteus densities are highest, as well as its preferred coral substrate on the fringing reef surrounding Bonaire, Dutch Caribbean. It also intended to demonstrate that the presence of S. giganteus could lessen the effects of disease and bleaching on the corals on which it lives. Using benthic transects at three different depths at two study sites, it was found that S. giganteus density was highest at shallower depths. The preferred substrate was found to be the boulder star coral, Orbicella annularis. Data regarding the effects of S. giganteus on coral disease and bleaching was too limited to determine any relationship between them, but it is recommended that this relationship be investigated in depth due to its possible role in recovering from coral bleaching

This student research was retrieved from Physis: Journal of Marine Science XIV (Fall 2013)19: 61-68 from CIEE Bonaire.

Date
2013
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

Factors affecting the distribution and abundance of Tripneustes ventricosus on Kralendijk’s waterfront

Coral reefs are being threatened by both anthropogenic and environmental factors. One prominent factor is the loss of herbivores on coral reefs due to overfishing and disease. Herbivores play a key role in coral reef ecosystems by grazing away competing algae that threaten coral survivorship and recruitment. The loss of Diadema antillarum in the Caribbean due to an unknown pathogen has been detrimental; however, there is another species of sea urchin emerging in the reef environment: Tripneustes ventricosus. Little is known about the environmental factors that influence the abundance and distribution of T. ventricosus in the reef environment. This study seeks to quantify the distribution and abundance of a particular population of T. ventricosus on the back reef found along the waterfront of Kralendijk, Bonaire, Dutch Caribbean. It also examines the effects of benthic composition and competition on the distribution of T. ventricosus. In order to examine these factors, 30-m transects were laid at three different distances from the waterfront wall at five sites. Quadrats were placed at 5-m intervals along each transect. Within each quadrat, algal, benthic, and sea urchin composition was observed and recorded. Water samples were taken from each site to test nitrogen concentration. The diversity and abundance of algae and substrate type appear to be factors influencing T. ventricosus’ distribution and abundance; competition did not appear to be a factor. The area of the abundance of T. ventricosus seems to have ideal conditions for T. ventricosus, and many other urchins, including D. antillarum, that were observed at this site indicating that it may be an ideal place for sea urchins in general.

This student research was retrieved from Physis: Journal of Marine Science XIV (Fall 2013)19: 14-24 from CIEE Bonaire.

Date
2013
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

An analysis of abundance, ecology and life history of the lettuce sea slug Elysia crispata on the island of Bonaire

With the exception of Elysia crispata, shell-less Sacoglossa species (Order: Mollusca), have been widely studied. Within the Caribbean, these small bodied organisms occur in low population densities, making them hard to find and, in turn, difficult to study. This project served to assess E. crispata abundance, ecology and life history traits on the island of Bonaire. Data collected for this study was conducted by observations from ten 40 m2 transects located at depths of 2.2 m, 7.9 m and 10.7 m. A pair of surveyors recorded the number of individuals found, size of individuals, substrate individuals were located on, and color intensity of individuals within each transect. Overall abundance of individuals found at the study sites were much higher than anticipated. Of the 275 individuals found, the highest population densities were found in shallow transects. The average size of individuals was between 3.0 ± 2.6 cm to 5.0 ± 3.8 cm (mean ± SD) in length, with no correlation between size of individual and coloration. Overall abundance of smaller individuals found on shallower transects could indicate higher densities of preferred substrate within these areas. Roughly 94% of individuals were found on various compositions of turf algae. These results implied that E. crispata were biased towards occupying substrates with turf algae compositions as opposed to other available substrates.

This student research was retrieved from Physis: Journal of Marine Science XVII (Spring 2015)19: 26-33 from CIEE Bonaire.

Date
2015
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

Abundance and diversity of fluorescent anemone species across reef habitats off the coast of Bonaire, Dutch Caribbean

Marine anemones influence oceanic food webs, partake in symbiotic relationships with many marine phyla, and can prove detrimental to coral reef ecosystems in excess. Few descriptive studies have been conducted on anemone communities. The present study examined anemone abundance and diversity using fluorescence across reef habitats in a coral reef ecosystem for the first time on Bonaire, Dutch Caribbean. A total of 110 fluorescent anemones belonging to at least 9 species were documented. Anemones exhibited species-specific ranges in one or multiple reef habitats including the reef flat (2-6 m depth), reef crest (6-9 m depth), and reef slope (9-15 m depth). Four possibly unidentified species were documented. Fluorescent anemone abundance varied significantly between reef flat (5.5 ± 0.7 individuals) and reef crest (27.5 ± 6.4 individuals) habitats. Although fluorescent anemone diversity was highest on the reef flat and lowest on the reef slope, there was no significant difference among the reef habitats. The study contributed to current knowledge on fluorescent anemone ecology by documenting species habitat ranges. It suggested that among species and as a whole, anemones are habitatspecific. The results also provided habitat ranges for obligate anemone symbionts. The study may be valuable for a variety of scientific fields. Descriptive studies such as the present project in Bonaire facilitate the possible discovery of new and groundbreaking species and model organisms. Tracking distribution and diversity could also inform of anemone bleaching and serve as a bioindicator of reef health and climate change ramifications.

This student research was retrieved from Physis: Journal of Marine Science XIX (Spring 2016)19: 74-84 from CIEE Bonaire.

Date
2016
Data type
Other resources
Theme
Research and monitoring
Geographic location
Bonaire
Author

Révision et mise à jour taxonomique de la liste et de la distribution des orchidées des Petites Antilles [An updated catalogue of Lesser Antilles Orchids and of their distribution]

Since the publication of a checklist of Lesser Antilles’ orchids not far of twenty years ago, the orchid family has been the subject of many studies and publications, including extensive taxonomic revisions, thanks to the use of molecular tools and to the improvement of data availability through Internet (virtual herbariums on line). The knowledge of his family and on its distribution has been largely improved. The analysis of these new data and of in situ intensive prospections has given a number of 138 species recorded in the Lesser Antilles (in March 2012), 130 of them being native. This apparently stable number compared to the 1993’s checklist comes from the suppression of some species and the addition of others. It is also a consequence of taxonomic changes for around one third of the taxa. Guadeloupe remains the richest island with 103 recorded species, followed by Dominica, with 90 species and Martinique with 80 species. Examination of all the types specimen on one island’s endemics does not support the endemism level sometimes described. There are only 5 true one-island endemic species, 3 to Guadeloupe (Basse Terre), one to Dominica and one to Montserrat. The rate of endemism in the Lesser Antilles is 16%, and 27% of the Lesser Antillean orchids are endemics to the West Indies.

Date
2012
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Saba
Author

The cetaceans of Aruba, southern Caribbean

Abstract:

Aruba is one of the most densely populated islands in the Caribbean. However, very little is known about its cetaceans. In 2010 and 2011, a total of 19721 km (1686 h) boat-based surveys over nearshore transects resulted in 117 positively-identified sightings comprising eight species. New records are also added for one of three previously-documented species. Five additional species were documented from strandings or reports by others. This brings the total number of cetacean species identified in Aruban waters to 16, of which nine are authenticated here for the first time. Atlantic spotted dolphin (Stenella frontalis (N 1⁄4 59) and bottlenose dolphin (Tursiops truncatus) (N 1⁄4 33) were the most frequently observed species, with sightings of both year-round, followed by spinner dolphin (S. longirostris) and false killer whale (Pseudorca crassidens). Additional species recorded are pantropical spotted dolphin (S. attenuata), striped dolphin (S. coeruleoalba), common dolphin (Delphinus capensis), rough-toothed dolphin (Steno bredanensis), short-finned pilot whale (Globicephala macrorhynchus), killer whale (Orcinus orca), Risso’s dolphin (Grampus griseus), humpback whale (Megaptera novaeangliae), Bryde’s/Eden’s whale (Balaenoptera brydei/edeni), sperm whale (Physeter macrocephalus) and an unidentified beaked whale (Mesoplodon sp.). All cetaceans were sighted within 22 km of the coast in relatively shallow waters. Sighting rate was low (0.69 cetacean sightings per 100 km). Sightings of calves and neonates indicate that Aruba may be a nursing or breeding area for some species. The presence of several species of cetaceans in Aruba’s coastal waters year-round indicates that status and threat assessments are needed to protect them. 

Date
2013
Data type
Scientific article
Theme
Research and monitoring
Geographic location
Aruba