Bahamas Research Articles

A qualitative and quantitative model for climate-driven lake formation on carbonate platforms based on examples from the Bahamian archipelago

Lakes on carbonate platform islands such as the Bahamas display wide variability in morphometry, chemistry, and fauna. These parameters are ultimately driven by climate, sea level, and carbonate accumulation and dissolution. The authors propose a model that integrates climatological, geomorphological, and stratigraphic frameworks to understand processes of carbonate-hosted lake formation and limnological characteristics in modern day environments, with applications to carbonate lake sedimentary records. Fifty-two lakes from San Salvador Island and Eleuthera, Bahamas, were examined for water chemistry, basin morphology, conduit development, conductivity, and major ions. Using non-metric, multi-dimensional scaling ordination methods, the authors derived a model dividing lakes into either constructional or destructional formational modes. Constructional lakes were further divided into pre-highstand and highstand types based on whether their formation occurred during a marine regressive or transgressive phase. Destructional lakes are created continually by dissolution of bedrock at fresh/saline water interfaces and their formation is therefore related to changing climate and sea level. This model shows that lake formation is influenced by the hydrologic balance associated with climatic conditions that drives karst dissolution as well as the deposition of aeolian dune ridges that isolate basins due to sea-level fluctuations. It allows for testing and examining the climatic and hydrologic regime as related to carbonate accumulation and dissolution through time, and for an improved understanding of lake sensitivity and response to climate as preserved in the lacustrine sedimentary record.

Functional gene diversity of oolitic sands from Great Bahama Bank

Despite the importance of oolitic depositional systems as indicators of climate and reservoirs of inorganic C, little is known about the microbial functional diversity, structure, composition, and potential metabolic processes leading to precipitation of carbonates. To fill this gap, we assess the metabolic gene carriage and extracellular polymeric substance (EPS) development in microbial communities associated with oolitic carbonate sediments from the Bahamas Archipelago. Oolitic sediments ranging from high-energy 'active' to lower energy 'non-active' and 'microbially stabilized' environments were examined as they represent contrasting depositional settings, mostly influenced by tidal flows and wave-generated currents. Functional gene analysis, which employed a microarray-based gene technology, detected a total of 12,432 of 95,847 distinct gene probes, including a large number of metabolic processes previously linked to mineral precipitation. Among these, gene-encoding enzymes for denitrification, sulfate reduction, ammonification, and oxygenic/anoxygenic photosynthesis were abundant. In addition, a broad diversity of genes was related to organic carbon degradation, and N2 fixation implying these communities has metabolic plasticity that enables survival under oligotrophic conditions. Differences in functional genes were detected among the environments, with higher diversity associated with non-active and microbially stabilized environments in comparison with the active environment. EPS showed a gradient increase from active to microbially stabilized communities, and when combined with functional gene analysis, which revealed genes encoding EPS-degrading enzymes (chitinases, glucoamylase, amylases), supports a putative role of EPS-mediated microbial calcium carbonate precipitation. We propose that carbonate precipitation in marine oolitic biofilms is spatially and temporally controlled by a complex consortium of microbes with diverse physiologies, including photosynthesizers, heterotrophs, denitrifiers, sulfate reducers, and ammonifiers.

Large-scale carbonate platform development of Cay Sal Bank, Bahamas, and implications for associated reef geomorphology

The Bahama Archipelago consists of an arcuate chain of carbonate platforms. Average water depths on the platform-tops, such as the Great Bahama Bank (GBB), are typically 10m or less, with coral reef-rimmed margins, thick sediment accumulations, and the frequent occurrence of islands. There are, however, exceptions. For example, Cay Sal Bank (CSB), a little studied detached Bahamian carbonate platform with depths ranging from 30 to 7m, is only slightly deeper than the GBB, but devoid of islands, lacks platform-margin coral reefs and holds little sediment on the platform-top; the platform is incipiently drowned. CSB is interesting as it is conspicuously larger (6000sq.km) than other incipiently drowned platforms in the region, such as Serranilla Bank (1100sq.km) and the Cat Island platform (1500sq.km). Field and remote sensing data are assembled to provide insight into the sedimentology and geomorphology of the CSB. The influence of ocean climate, regional hydrodynamics, and Holocene flooding history are investigated to understand why platform-margin coral reef growth on CSB has been unable to keep pace with Holocene sea-level rise. A decade of regional sea-surface temperature data for the Bahamas report CSB to be situated in the same ocean climate regime as GBB. Temperature cannot explain the platform's different morphologies. The Florida Current has been evoked as a possible reason for the immature development of platform-top processes on the CSB, but numeric modeling suggests its influence to be restricted to the deep flanks of the bank. Further, sediment distribution on CSB, including infill patterns of karst depressions, suggest trade winds (easterlies) to drive platform-top hydrodynamics. By assembling a satellite-derived bathymetry map, it can be shown that CSB flooded earlier and at relatively higher rates of Holocene sea-level rise than its neighboring platforms. Flooding history is identified as the most feasible explanation for the atypical morphology of the CSB. By contrasting the present-day morphology of the CSB and the GBB, the work emphasizes how subtle differences in relative sea-level history can influence the growth of platform-margin coral reefs, features that in turn can conspire to set even closely neighboring carbonate platforms on divergent paths with regard to the development of marine landforms. This insight is relevant to interpreting the morphological diversity of carbonate platforms in the modern ocean and in the rock record.

Learning through experience: Non-implementation and the challenges of protected area conservation in The Bahamas

Marine Protected Areas (MPAs) are increasingly promoted as policy tools to counter such problems as declining fisheries, habitat destruction, and biodiversity loss. Many proposed MPAs become stalled in the implementation process, highlighting the need for further research into the processes leading to non-implementation. This paper focuses on two proposed MPAs in The Bahamas undergoing protected area enclosure: one highly controversial MPA in North Bimini that was proposed in 2000, but with an uncertain future; and a second enclosure in Andros Island initiated in 2002 and enlarged in 2009 after years of outreach and assessment. Although both locations seek to protect an area of shallow seas within The Bahamas archipelago, each area is significantly different in its management goals as well as social and institutional frameworks. A comparison of the two MPAs underscores the challenges in implementing changes in marine governance while illustrating opportunities for adaptive social learning in resource management processes. There are three goals to this analysis: (1) to explore the processes leading to non-implementation of proposed MPAs; (2) to identify some conditions for success and failure of MPAs within The Bahamian context; and (3) to search for evidence of individual and institutional learning in how conservation agents have approached the later Andros MPA. Research suggests that while there may be ample opportunity to learn from failed conservation attempts, individual and institutional constraints inhibit successful conservation planning frequently leading to non-implementation.

A new species of Late Pleistocene rail (Aves: Rallidae) from Abaco, the Bahamas

We describe a new species of rail from the Sawmill Sink blue hole on Abaco Island in the northern Bahamas. Known from abundant, beautifully preserved Late Pleistocene fossils, Rallus cyanocavi sp. nov. was a medium-sized, flightless species that probably was endemic to the Little Bahama Bank, which is a carbonate platform surrounded by deeper water. We are uncertain whether R. cyanocavi survived into the Holocene, when higher sea levels transformed the Little Bahama Bank from a single large, Late Pleistocene island (ca. 12000 km2) to the scattering of smaller islands seen today, the largest of which is Abaco (1681 km2). Fossils of additional extinct, flightless species of Rallus probably await discovery on some of the 21 other carbonate banks that span the Bahamian Archipelago.

Direct Line to the TropicsSLP Shameka Johnson is finding a way to provide much-needed services to families in the Bahamas—and saving them money, too.

Direct Line to the TropicsSLP Shameka Johnson is finding a way to provide much-needed services to families in the Bahamas—and saving them money, too.

New island records for amphibians and reptiles on the Little Bahama Bank, Commonwealth of The Bahamas

New island records for amphibians and reptiles on the Little Bahama Bank, Commonwealth of The Bahamas

Bacterial community of oolitic carbonate sediments of the Bahamas Archipelago

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 485:9-24 (2013) - DOI: https://doi.org/10.3354/meps10359 Bacterial community of oolitic carbonate sediments of the Bahamas Archipelago Mara R. Diaz1,*, Alan M. Piggot2, Gregor P. Eberli2, James S. Klaus2,3 1Marine Biology and Fisheries, and 2Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida 33149, USA 3Department of Geological Sciences, University of Miami, Coral Gables, Florida 33146, USA *Email: mdiaz@rsmas.miami.edu ABSTRACT: The present study characterized bacterial communities associated with oolitic carbonate sediments from the Bahamas Archipelago, ranging from high-energy ‘active’ to lower energy ‘non-active’ and ‘mat-stabilized’ environments. Bacterial communities were analyzed using terminal restriction fragment length polymorphisms (TRFLP), clone analyses of the 16S rRNA gene, confocal laser scanning microscopy (CLSM) and the quantitative phenol-sulfuric acid assay for extracellular polymeric substances (EPS). Confocal imaging of oolitic grains stained with cyanine dye-conjugated lectin and EPS quantification demonstrated that all 3 environments harbored attached biofilm communities, but densities increased from the active to the mat-stabilized environment. Bacterial communities associated with all 3 settings were highly diverse and dominated by Proteobacteria (50 to 61%). Analysis of similarity (ANOSIM) and similarity percentages (SIMPER) revealed significant differences among the 3 environments in the relative abundance of Proteobacteria, Planctomycetes, Cyanobacteria, Chlorobi, and Deinococcus-Thermus. Bacterial primary production in the active shoal environment was associated with Rhodobacteraceae, Ectothiorhodospiraceae, and Chlorobi, whereas the lower energy environments appear to harbor a more complex consortium of aerobic photoautotrophs and anaerobic/aerobic anoxygenic phototrophs. The ubiquitousness of photosynthetizers, along with the presence of aerobic/anaerobic heterotrophic microbes (e.g. denitrifiers, sulfate-reducers, biofilm producers/degraders) and the gradient increase in biofilm production on ooid grains from active to mat-stabilized environments, support the potential involvement of these communities in biomineralization and carbonate precipitation. KEY WORDS: Ooids · Carbonate sediment · Carbonate precipitation · 16S rRNA diversity · Bacterial community · Biofilm Full text in pdf format Supplementary material PreviousNextCite this article as: Diaz MR, Piggot AM, Eberli GP, Klaus JS (2013) Bacterial community of oolitic carbonate sediments of the Bahamas Archipelago. Mar Ecol Prog Ser 485:9-24. https://doi.org/10.3354/meps10359 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 485. Online publication date: June 27, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Molecular phylogeny and historical biogeography of West Indian boid snakes (Chilabothrus)

The evolutionary and biogeographic history of West Indian boid snakes (Epicrates), a group of nine species and 14 subspecies, was once thought to be well understood; however, new research has indicated that we are missing a clear understanding of the evolutionary relationships of this group. Here, we present the first multilocus, species-tree based analyses of the evolutionary relationships, divergence times, and historical biogeography of this clade with data from 10 genes and 6256bp. We find evidence for a single colonization of the Caribbean from mainland South America in the Oligocene or early Miocene, followed by a radiation throughout the Greater Antilles and Bahamas. These findings support the previous suggestion that Epicrates sensu lato Wagler is paraphyletic with respect to the anacondas (Eunectes Wagler), and hence we restrict Epicrates to the mainland clade and use the available name Chilabothrus Duméril and Bibron for the West Indian clade. Our results suggest some diversification occurred within island banks, though most species divergence events seem to have occurred in allopatry. We also find evidence for a remarkable diversification within the Bahamian archipelago suggesting that the recognition of another Bahamian endemic species C. strigilatus is warranted.

Multicenter study of human papillomavirus and the human papillomavirus vaccine: knowledge and attitudes among people of African descent.

Objective. To compare knowledge and attitudes of human papillomavirus (HPV) and the vaccine between different cultures of African descent. Methods. A cross-sectional survey of 555 African-Americans and Afro-Caribbeans residing in the US and the Bahamas (BHM) was conducted. Results. General knowledge about HPV and the HPV vaccine differed between the two countries significantly. Bahamian respondents were less likely to have higher numbers of correct knowledge answers when compared to Americans (Adjusted Odds Ratio [Adj. OR] 0.47, 95% Confidence Interval [CI] 0.30–0.75). Older age, regardless of location, was also associated with answering fewer questions correctly (Adj. OR 0.61, 95% CI 0.40–0.92). Attitudes related to HPV vaccination were similar between the US and BHM, but nearly 80% of BHM respondents felt that children should not be able to receive the vaccine without parental consent compared to 57% of American respondents. Conclusions. Grave lack of knowledge, safety and cost concerns, and influence of parental restrictions may negatively impact vaccine uptake among African-American and Afro-Caribbean persons. Interventions to increase the vaccine uptake in the Caribbean must include medical provider and parental involvement. Effective strategies for education and increasing vaccine uptake in BHM are crucial for decreasing cervical cancer burden in the Caribbean.

Two Recorded Sessions from Bahamas

Two Recorded Sessions from Bahamas

Tinker, Keith L.: The Migration of Peoples from the Caribbean to the Bahamas

Anthropos , Seite 372 - 372

The Migration of Peoples from the Caribbean to the Bahamas. Keith L. Tinker. Gainesville: University Press of Florida, 2011. x + 199 pp. (Cloth US$ 69.95)

The Migration of Peoples from the Caribbean to the Bahamas. Keith L. Tinker. Gainesville: University Press of Florida, 2011. x + 199 pp. (Cloth US$ 69.95)

Florida, Cuba and the Bahamas

Florida, Cuba and the Bahamas

Florida, Cuba and the Bahamas

Florida, Cuba and the Bahamas

Abolition of the perpetuities rule in The Bahamas

Abolition of the perpetuities rule in The Bahamas

Genetic diversity and conservation ofIpomoea microdactyla(Convolvulaceae): an endemic vine from the Bahamas, Cuba, and southeastern Florida

AbstractIpomoea microdactylaGriseb. (Convolvulaceae) is restricted to the Bahamian archipelago, Cuba, and southeastern Florida. The species is listed as a state endangered species in Florida, where it is mostly restricted to the hyperfragmented pine rockland of Miami‐Dade County. Using seven DNA microsatellite loci, we assessed levels of genetic diversity for 12 populations of this species from Andros Island in the Bahamas (six sites), Cuba (one site), and Florida (five sites). We found significantly greater mean numbers of alleles, and higher mean values for both observed and expected heterozygosity in populations from the continuous forest on Andros than those from the habitat fragments in Florida. It is unknown if these patterns of genetic diversity in the Florida populations are the result of habitat fragmentation or founder effects. The population from Cuba exhibited relatively high levels of genetic variation, suggesting that this island is a major center of diversity and dispersal for this species. It appears that hybrid introgression forI. carolinaalleles withinI. microdactylaindividuals occurred at a single site on Andros Island. Overall, the mean inbreeding coefficient value was 0.089, suggesting low levels of inbreeding. The highest inbreeding coefficient values were mostly recorded in Florida. Two groups were revealed, one containing the populations from Florida, and the second one encompassing those from the Bahamas and Cuba. Our results highlight the negative genetic consequences of habitat fragmentation and support initiatives recently established to establish corridors to connect the remnants of the pine forest of the Miami‐Dade County.

Genetic analysis of an endemic archipelagic lizard reveals sympatric cryptic lineages and taxonomic discordance

The importance of genetic data in biodiversity conservation is well established, and knowledge of standing genetic variation within and between populations is important for designing conservation strategies. We investigated partitioning of genetic diversity in an endemic lizard (Leiocephalus psammodromus) distributed in the Turks and Caicos archipelago using mtDNA and AFLP data from 259 individuals sampled across 13 islands. Current taxonomy identifies six or more subspecies of L. psammodromus within the archipelago, several of which have undergone recent drastic reductions in range due to extirpation. However, our results indicate the presence of two independent lineages, one on each of the Turks and Caicos banks, and a third sympatric cryptic lineage on both banks. These lineages do not correspond to current taxonomy and alter our understanding of diversity and conservation of this species. Gross morphological data (mass and snout-vent length) indicate some variation in female size among lineages, indicating the possibility of cryptic morphological variation. Instead of initiating separate conservation measures for nominate subspecies, we recommend a more thorough investigation of the morphology and genetics of this group and a more inclusive conservation program. Our surprising results indicate that other endemic squamates in the Bahamas Archipelago might also exhibit sympatric cryptic diversity that does not correspond to current taxonomic understanding and could have significant impacts on our approach to conservation in this region.

Do invasive rodents impact endangered insular iguana populations?

Ample evidence confirms that large invasive mammalian competitors and predators can devastate endangered insular iguana populations. However, the impact of invasive rodents, particularly rats (Rattus rattus), has remained elusive. Tail autotomy occurs frequently in lizards, often as an antipredator tactic, but sometimes from intraspecific aggression. Tail autotomy can incur substantial locomotor, behavioral, energetic, and survival costs. Furcation (i.e., dividing into branches) of regenerated tails may also result from attempted predation but occurs much more rarely, and with unknown costs. To evaluate the potential impact of invasive rodents—primarily rats—on West Indian rock iguanas (genus Cyclura), we compared tail-break and tail-furcation frequencies among 19 insular iguana populations (3,537 individuals) representing three species in the Bahamian Archipelago (including the Turks and Caicos Islands). The findings supported our three hypotheses: (1) that tail-break and tail-furcation frequencies are significantly higher in populations coexisting with invasive rodents; (2) that tail-furcation results primarily from failed predation attempts rather than intraspecific aggression; and (3) that frequencies of tail breaks and tail furcation are associated with each other, suggesting a degree of commonality in cause-effect (i.e., failed predation attempts). Tail furcation, in contrast to tail breakage, never occurred on islands lacking invasive mammalian predators. We conclude that invasive rodents, particularly rats, may have a greater impact on endangered insular iguana species than previously recognized.

DEATH AND DISINTEGRATION IN BAHAMAS: TAPHONOMIC PATTERNS AND PROCESSES IN TROPICAL ISLAND SETTINGS

We are thrilled to present this special issue of PALAIOS that highlights projects of students who attended a field course offered in the summer of 2010 at the Gerace Research Centre, San Salvador Island, Bahamas. The course, supported by a generous grant from the Paleontological Society, was devoted to taphonomic and ecological processes in tropical environments. The attendees were an international group of students (see group photo) with diverse backgrounds and disparate scholarly interests. The success of this course, as demonstrated by the research papers assembled in this volume and numerous student presentations at annual meetings of the Geological Society of America, reflects a combination of two factors: the unwavering dedication of the involved students during and after the course, and extraordinary research opportunities represented by San Salvador Island and the Gerace Research Centre (www.geraceresearchcentre.com). The participants of the 2010 summer course, Taphonomy and Ecology of Tropical Environments, in front of the Gerace Research Centre, San Salvador Island, Bahamas. The foreground, from left to right: Yurena Yanes (University of Granada, Spain), Jacalyn Wittmer (Virginia Tech), Maria Sol Boyer (Universidad Nacional de Cordoba, Argentina), Poncho (the Centre's vicious guard dog), and Amelinda Webb (Yale University); front row, standing, from left to right: Laura Vietti (University of Minnesota), Jeanine L. Ash (University of Arizona), Emilia Jarochowska (University of Warsaw), Carrie Tyler (Virginia Tech), Rachel Hertog (University of California, Davis), Janina Dynowski (University of Tubingen), Chrissy Spencer (University of Colorado), Emily King (University of Chicago), Schimmel Majken (Virginia Tech), and Simon Darroch (Yale University); second row, standing, from left to right: Troy Dexter (Virginia Tech), Rafal Nawrot (University of Warsaw), Michal Kowalewski (Virginia Tech), and Tom Rothfus (Gerace Research Centre). San Salvador Island is one of the outermost islands of the Bahamian Archipelago, a chain of several hundred islands, islets, and banks …