Biodiversity

St. Maarten is one of the islands forming the inner arc of the Lesser Antilles. It is older than Saba and St. Eustatius. The oldest rock strata date from ± 50 million years ago. The island experienced periods of uplift and descent. In the Pleistocene period it formed one island together with Anguilla and St. Barths.

St. Maarten is irregular in form because of the many bays and lagoons. Steep rocky coasts alternate with sandy beaches. The major part of the island is hilly. Three ridges can be distinguished in the north-south direction. Only the Low Lands in the west are flat. In the past St. Maarten was a plantation island, with sugarcane cultivation reaching high up into the hills. Now tourism is the main economical activity. The island has two parts: The French and the Dutch part. About 38.000 people live on St. Maarten on the Dutch side, especially in the valleys, but also more and more in the hills. Because of the high population density and tourism development a lot of nature has already been lost, and several habitats are under pressure. According to the system of Köppen the climate of Maarten falls between a savanna and monsoon climate. The island is situated in the Atlantic hurricane zone. In September 1995 St. Maarten was hit by a severe hurricane.

At least 522 wild plants are known from St. Maarten, divided in 506 seed plants and 16 ferns. Among the plants there are two island-endemic species: Calyptranthes boldinghgii en Galactia nummelaria. Both species are very rare or have possibly disappeared already. The geographical distribution of five plants is limited to just a few islands and 3.3% of the species is endemic to the Lesser Antilles and the Virgin Islands. With respect to the moss flora, only two true mosses are known, and no liverworts.

The major part of the Dutch side of St. Maarten is covered with secondary vegetation derived from either seasonal formations or dry evergreen formations. Only on the top of the hills some more or less original semi-evergreen seasonal forest is found. This type of forest has regionally become extremely rare too. Locally it includes several species that are lacking elsewhere in the island. Because of its small area this forest formation is very vulnerable. On the higher hills of the two ridges in the middle part of the island, and on the hills of the eastern ridge, a dense secondary woodland vegetation is growing, preventing erosion and with a high scenic value. Along the coast and inland waterways remains of mangrove forests and other types of coastal vegetation survive, which are of high ecological value, and also have scenic value.

The fauna of St. Maarten is poor in species, not only because of St. Maarten’s small size, but also because of habitat destruction, hunting, imported predators and hurricanes. One bird species, the Red-tailed Hawk, Buteo jamaicensis, and two kinds of reptiles, the Antillean Iguana Iguana delicatissima and the original population of the Green Iguana, Iguana iguana, have already been exterminated. Among the vertebrates, birds form the largest group. Especially the number of migrating birds and visitors is big. In total there are 39 resident and nesting birds on St. Maarten and 68 species of migrating birds and visitors have been observed. These include 19 sea birds, of which 10 species breed in or in the vicinity of the island. St. Maarten is classified as an important breeding area for seabirds. Several small rocky islands just off shore accommodate breeding colonies of seabirds. 2 Amphibians and reptiles are the next largest group of vertebrates. They are represented by 15 species. Bats are probably the only native mammals. There are six species on St. Maarten.

The subspecies of the tree lizard Anolis wattsi pogus can be regarded as an island-endemic species. The animal is extinct in other islands. Several vertebrates are endemic for the Lesser Antilles and the Virgin Islands, either at the species level or the subspecies level: one bat, one amphibian and six reptiles. The ground lizard Ameiva pleei, the tree lizard Anolis gingivinus, the gecko Sphaerodactylus sputator, the Grass-snake Alsophis rijersmai and the subspecies of the gecko Sphaerodactylus macrolepis parvus are limited to only a few islands. The White crowned Pigeon Columba leucocephala and the Red-Necked Pigeon Columba squamosa, both regionally and locally rare because of hunting, are still found in the island and could increase because of the diminished pressure of hunting. Among the breeding seabirds three, Audubon’s Shearwater Puffinus lherminieri lherminieri, the Brown Pelican Pelecanus occidentalis occcidentalis, and the Roseate Tern Sterna dougallii dougallii, are endangered and three, the Red-billed Tropicbird Phaeton aethereus mesonauta, the Sooty Tern Sterna fuscata fuscata, and the Least Tern Sterna albifrons antillarum, are possibly endangered. Of the invertebrates not much more is known than 170 names.

The main threats to the biodiversity of St. Maarten are habitat destruction and degradation caused by the growth of inhabited areas, tourism development and pollution. Since the fifties several people argued for the need to preserve valuable nature areas, not only for ecological motives, but also for the benefit of tourism. Stinapa-St. Maarten, the later St. Maarten National Heritage Foundation, and Stinapa Netherlands Antilles, have struggled continuously to establish a hilltop protected area and a nature/culture reserve Belvédère/Bishophill. Their aim should be supported. At present the necesary island legislation is being worked on. For effective nature management in St. Maarten complete floristic surveys are necessary, and further studies of the status of the island populations of regionally and locally scarce and/or endangered species. For now, a few conclusions can be drawn regarding the conservation of biodiversity on St. Maarten. For this conservation it is necessary to safeguard the largest possible contiguous areas of nature. To this aim the following areas are recommended for conservation and management: the ‘Hillsides’, Naked Boy Hill and surroundings, and the hills and coastal area between Guana Bay en Back Bay. For the benefit of the bats the top of Billy Folly is recommended, and for the avifauna the various ponds, coastal habitats and the little islands Pelican key, Molly Beday and Hen and Chickens.

Greater ecosystem diversity generally results in greater fish diversity. It follows that areas of greater ecosystem diversity would also exhibit greater larval fish diversity during recruitment events. To test the idea that larval fish would be more diverse in areas with greater ecosystem diversity, two sites on Bonaire, Netherlands Antilles were selected for study based on the amount of ecosystem diversity in each area. At Lac Cai, on the windward side of Bonaire, there are fringing reefs, a small barrier reef, seagrass beds, sand flats, and a mangrove lined bay. On the leeward side of the island in front of Kralendijk, the habitat is predominately fringing reef and sand flats. Three collection methods (plankton tows, light traps, and dip netting) were used to test my hypothesis that larval fish diversity at Lac Cai will be greater than that in front of Kralendijk due to greater ecosystem level diversity at Lac Cai. Simpson’s index of diversity (1-D) for Lac Cai (range 0.827 to 0.829) was significantly higher (one-tailed t-test assuming equal variance, p = 0.007, α = 0.05) than the values at Kralendijk (range 0.615 to 0.664) indicating that higher ecosystem diversity does result in higher larval fish diversity

This student research was retrieved from Physis: Journal of Marine Science IV (Fall 2008)19: 19-24 from CIEE Bonaire.

Biodiversity of coral reef fish species is often related to the structural complexity and diversity of their habitats. This study explores the relationship between fish species richness, habitat diversity (substrate diversity) and habitat complexity (rugosity). Habitat diversity and topographic measures were used to predict reef fish diversity. It was hypothesized that high fish species diversity would show a positive correlation with greater habitat structure, which includes habitat diversity and topographic complexity. Fish species richness was determined at six dive sites in Bonaire, N.A. (Karpata, Andrea II, Cliff, Windsock, Angel City, and Red Slave) using data from 20 randomly chosen expert-level surveys provided by Reef Educational Environmental Foundation (REEF) for 2004 – 2009. Preliminary analysis of REEF data was used to select sites with high and relatively low fish species richness to make comparisons with the habitat structural complexity measurements (substrate diversity and rugosity). Substrate diversity and habitat complexity were measured using a 10 m transect randomly placed at 4 depths (2, 6, 12, and 18 m) at each site. Substrate diversity was determined by measuring the percent cover of the different substrates and then using the Shannon Diversity Index to determine H’. The rugosity of the sample area was measured by fitting a lead line to the reef at each of the determined depths. Overall results suggested that topographical complexity (rugosity) was not related to high fish species richness at dive sites on Bonaire. There was a weak positive correlation between H’ and fish species richness on the reef slope and a weak negative relationship between H’ and fish species richness on the reef flat. The results provide evidence that there are more factors to consider when explaining fish species richness on coral reefs than the structural complexity of the habitat at the scale of this study.

This student research was retrieved from Physis: Journal of Marine Science VI (Fall 2009)19: 66-72 from CIEE Bonaire.

Bioindicator species have been used to determine changes in water quality and the effect of pollution at sites of environmental concern. Increasingly degraded water quality throughout the Caribbean is leading marine park managers and scientists to use bioindicator organisms to rapidly detect differences in water chemistry by determining connections between environmental parameters and changes in reef fish communities. This study sought to determine bioindicator prey species that could provide early detection of changes as a result of anthropogenic activities in the coastal waters of Bonaire, N.A. The effects of these parameters on the density and diversity of reef fish species was compared between 4 sites of “more (MI)” and 4 sites of “less (LI)” anthropogenic impact (200 m from of coastal development, respectively). Fish communities were surveyed using a modified version of the AGRRA methodology during the morning and evening. Two 30x2 m transects at 12 m depth were used at each site to survey both prey and predator fish species. Water chemistry including nutrient, bacterial and sedimentation levels were also analyzed to attempt to determine the factor(s) driving the changes. This study revealed significantly greater densities and a higher diversity of prey and predatory fish species at MI sites versus LI sites during the morning and the evening. The species that was found at greatest densities for both LI and MI sites was Stegastes partitus, with significantly more S. partitus at MI sites during both the morning and evening. Thus, S. partitus may be a possible bioindicator of stressors on the reefs in Bonaire. The use of S. partitus as a bioindicator of anthropogenic stress may help increase the effectiveness of marine management protocols in Bonaire and provide a basis for determining bioindicator species for monitoring coastal water quality throughout the Caribbean. None of the water chemistry parameters studied differed between MI and LI sites, therefore, the driver(s) of the differences in prey species (e.g. S. partitus) may be unaccounted for in this study as a result of time lags in the coral reef ecosystem.

This student research was retrieved from Physis: Journal of Marine Science VII (Spring 2010)19: 12-20 from CIEE Bonaire.

Stenorhynchus seticornis (Yellowline arrow crab) is a decapod crustacean native to the Western Atlantic in tropical and subtropical climates. Stenorhynchus seticornis is abundant in the Caribbean and has been studied associating with many different species from different phyla. Bonaire is a small island in the Southern Caribbean where S. seticornis is common, however no research on S. seticornis has been published on Bonaire. This study provides new information on S. seticornis and its ecological role on the reefs of Bonaire. This study examined the habitat type, habitat substrates, behaviors, and inter-species associations of S. seticornis by surveying at two depths, 8 and 14 m. Stenorhynchus seticornis was observed more frequently at 14 m (n = 53) compared to 8 m (n = 27). There was a higher frequency of inter-species associations and more total species observed associating at 14 m compared to 8 m. The majority of S. seticornis at 8 m were observed on sand under ledges, while at 14 m S. seticornis were recorded primarily on turf algae in crevices. The predominant behavior of S. seticornis at 8 and 14 m were eating and hiding respectively. The data collected contributes new information about S. seticornis, which is an abundant crustacean in Bonaire and is not fully understood. The results suggest that S. seticornis associates across many phyla and could serve an important role in the larger coral reef ecosystem. 

This student research was retrieved from Physis: Journal of Marine Science XIX (Spring 2016)19: 35-41 from CIEE Bonaire.

Plankton are the base of the marine food web and are studied for a broad range of research relating to diversity and ocean health. These organisms have not been well studied in Bonaire and this study provided a preliminary assessment for the pelagic net plankton movement and diversity. Water samples and plankton tows were collected using a Niskin bottle and 20-micrometer closable plankton net respectively at four depths: 90 m, 60 m, 30 m, and 10 m. The water samples were processed for nitrate concentration and the 5-meter vertical plankton tows were analyzed for plankton abundance using the following categories: diatoms, dinoflagellates, copepods, and other zooplankton. Dinoflagellates displayed diel vertical migration with higher density at 10 m and 30 m during the day and lower density at 10 m and 30 m at night. Simpson’s Diversity Index (SDI) did not show a significant difference in the diversity at 90 m and 10 m during the day or night. Nitrate concentration and plankton density were not found to be correlated. This study created a preliminary assessment for further research into the effects of the lunar cycle, nitrate, and movement of the pelagic net plankton of Bonaire.

This student research was retrieved from Physis: Journal of Marine Science XIX (Spring 2016)19: 28-34 from CIEE Bonaire.

St. Eustatius, also informally known as "Statia" is an 11.8 square mile (30.6 square km) island with about 3,200 permanent inhabitants located off the coast of St. Maarten (go to map from link in banner). English is the official language of the island but Dutch is also taught in schools and is spoken by many Statians.

In January 2008, The New York Botanical Garden, in partnership with the St. Eustatius National Parks Foundation (STENAPA), the Department of Environment and Nature (MINA) of the Netherlands Antilles, and Conservation International, embarked on a project to survey the plants and lichens of Statia. (See photobook from the expedition.)

Although relatively small in size, Statia's topography is covered by several vegetation types with a variety of soil types, ranging from beach forest at sea level to elfin forest on the summit of The Quill, a dormant volcano, at some 600 m elevation. Our goal is to provide illustrated checklists (a virtual museum) of all of the plants and lichens that grow on Statia. Both native and introduced species are included.

To find collections representing species of flowering plants, gymnosperms, ferns, bryophytes, or lichens, you can access the information available for a given group by clicking on the appropriate image on the left hand side of this page.

It is forbidden to pick plants and to remove plants from the island of Statia. All natural history studies must first be approved by the government of The Netherlands. To find out how to obtain permission to collect herbarium specimens, as was done in this study, contact STENAPA. All photographs are copyrighted by the photographer, Carol Gracie, unless otherwise noted. For permission to use the images, contact the photographers. Citizens of Statia have permission to download images from the website for personal or educational purposes.

Saba is a five square mile island with about 1200 permanent inhabitants located off the coast of St. Maarten in the Netherlands Antilles (go to map from link in banner). English is the official language of the island but Dutch is also taught in schools and is spoken by many Sabans.

In February 2006, Conservation International, in conjunction with the Saba Conservation Foundation, embarked on a project to survey the biodiversity of Saba from beneath the sea to the summit of its highest peak, Mt. Scenery. As part of this effort, the Department of Botany of the Smithsonian Institution surveyed the marine algae.

In 2006 and 2007, The New York Botanical Garden participated in surveying the bryophytes, lichens, and vascular plants of the island. Although small in size, Saba's rugged topography is covered by several vegetation types, ranging from near desert to cloud forest. Our goal is to provide illustrated checklists (a virtual museum) of all of the plants and lichens that grow on Saba and in the surrounding sea. Both native and introduced plants are included.

To find collections representing species of flowering plants, gymnosperms, ferns, bryophytes, marine algae, or lichens, you can access the information available for a given group by clicking on the appropriate image on the left hand side of this page.

It is forbidden to pick plants and to remove plants from the island of Saba. All natural history studies must first be approved by the government of Saba. To find out how to obtain permission to collect herbarium specimens as was done in this study contact the Saba Conservation Foundation.

All photographs are copyrighted by the photographer. Most of the photographs of the flowering plants, gymnosperms, ferns, bryophytes, and lichens were taken by Carol Gracie and most of those of the marine algae were taken by Diane Littler. Harrie Sipman took the photo micrographs of the lichens. For permission to use the images, contact the photographers. Citizens of Saba have permission to download images from the website for personal or educational purposes.

1. An often overlooked mechanism driving local extinction or scarcity of species is the selective  plant extraction by humans. Not much scientific attention has been paid to selective plant harvesting and the use of plants by inhabitants of the former Dutch Antilles. The aim of this study was to make a rapid sustainability assessment of wild plant harvesting on Sint Eustatius. A quantitative plot inventory was done to gather abundancy data on plants in the wild, and 31 interviews were conducted to collect information on local names, plant uses, preparation methods and harvesting locations. In total, 181 plant species belonging to 63 different plant families were mentioned as useful by the inhabitants of Sint Eustatius. Of these species, 66 were harvested exclusively from wild sources. Several wild species were cultivated in gardens. We found four wild-harvested species (Melocactus intortus, Nectandra coriacea, Pilosocereus royenii and Chiococca alba) that may encounter sustainability problems in the future, or might experience them already. From our study we can conclude that for the majority of useful species on Sint Eustatius, plant extraction does not form an immediate threat to their survival. 

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.