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Exuma Cays _The Centre for Ocean Research and Education

Past Projects

We assessed the system wide octopus density in an anchialine lake to provide an updated estimate on density to compare with original records from the 1980's. Given depressed habitat availability 40 years ago and contemporary increases in human impact at this unique site, we predicted that this octopus population may have undergone density and distribution shifts in response to changing conditions.

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Nocturnal surveys of lined seahorses reveal increased densities and seasonal recruitment patterns

Nocturnal surveys play an integral part in assessing fish assemblages and the selective forces shaping them. Population surveys for seahorses and their potential predators were conducted at midnight and midday during wet and dry seasons in an isolated salt-water lake, possessing morphological characteristics distinct from those found in the ocean.

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Feeding wildlife as a tourist activity is a growing industry around the world. However, providing alternative food sources can affect wildlife ecology and behaviour. In this study, we combined animal-borne cameras on five sub-adult green turtles (Chelonia mydas) from the Bahamas with a global review to directly assess impacts of provisioning on the behaviour of an endangered marine species for the first time

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Green turtles shape the seascape through grazing patch formation around habitat features: experimental evidence

To investigate the response of megaherbivores (green turtles) to habitat features, we experimentally introduced structure at two spatial scales in a shallow seagrass meadow in The Bahamas. While the role of habitat structure has been studied within the context of predator–prey dynamics and grazing behavior in terrestrial systems, there is a limited understanding of how structure influences megaherbivore grazing in marine ecosystems.

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The organic carbon stored in seagrass meadows is globally significant and could be relevant in strategies to mitigate increasing CO2 concentration in the atmosphere. Most of that stored is in the soils that underlie the seagrasses. We explored how seagrass and soil characteristics vary among seagrass meadows across the geographic range of turtlegrass (Thalassia testudinum) with a goal of illuminating the processes controlling soil organic carbon (Corg) storage spanning 23° of latitude

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We deployed standardized replicate consumer assays of raw squid, dried squid, and seagrass across seven sites in seagrass beds encompassing 20 degrees of latitude (from Crystal River, Florida, USA in the north to Bocas del Toro, Panama in the south) and across three seasons (summer, winter, and spring). We used video-recordings and visual observations of these assays to quantify relative rates of predation, meso-predation, and herbivory over 24 hours.

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An assessment of tidal restoration projects on the spatial ecology of economically important fish species from The Bahamas

This project was designed to assess movement within, between and among what was once a single - very large - intertidal mangrove creek system in South Eleuthera, The Bahamas. Due to the introduction of culverts as the island increases its urban planning, we investigated through aerial surveys the impacts this had on economically important species and their spatial movements among these creeks

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 Comparative survey methodologies for a multispecies shark community at a private island in the western Bahamas

This project established a long term monitoring program of a multispecies shark community in the Western Bahamas using different methodologies to calculate relative abundance and determine how different survey techniques (n=3) chagned overall catch per unit effort data for fisheries independent data acquisition. 

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Assessing relationships between coral reef complexity and fish diversity and abundance from two sites in Honduras

Using photogrammetry which produces 3D renderings of habitats as well as individual organisms, we selected two sites in Honduras with gradients of human impact to uncover how reef complexity altered fish community dynamics and associated biodiversity.

 

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Long held notions of the universally asocial octopus are being challenged due to the identification of high-density and interacting octopus populations in Australia, Indonesia, Japan and the deep sea. This study experimentally assessed the social tolerance and presence of potential prey items of Caribbean reef octopus, Octopus briareus, in a tropical marine lake, by deploying artificial dens in multi-den groups or ‘units’ and we presented evidence of possible antisocial den use by O. briareus, a modification of the default ‘asocial’ ignoring of conspecifics typically attributed to octopus,

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Temperature and herbivory drive spatial variation in seagrass recovery across the tropical Western Atlantic

Global change-related shifts in environmental factors can disrupt the functioning of habitat-forming primary producers, with resilient foundation species expected to withstand and adapt to environmental change. In this study, we assessed the impact of fertilisation, herbivory, and other environmental factors (irradiance, temperature) on the resilience of tropical seagrass along a latitudinal gradient. We measured resilience as plant recovery from small-scale perturbations (removal of above-and below-ground biomass) at ten sites in the Western Atlantic.

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Evidence and description of a nursery habitat for an endangered stingray  from The Bahamas

Understanding site characteristics for the early life history of endangered species is critical for developing conservation strategies. Here, we used a combination of mark-recapture and benthic habitat survey to describe long-term site fidelity (months - years) of Styracura schmardae for the first time, and provided evidence and characteristics of a nursery environment for this species. 

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Baited remote underwater video surveys are a well-established tool used in assessing relative abundances of marine fauna but are not commonly used in enclosed environments such as lakes. We investigated differences in community composition among multiple sites and attempted to identify the species/benthic components driving changes in community structure between day and night periods.

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An increasing number of studies are applying novel genetic tools to assess familial relationships of marine organisms to underpin management and conservation efforts. Here, we describe the reproductive population structure of the endangered Atlantic Chupare stingray (Styracura schmardae) from The Bahamas using a double digest restriction-site-associated DNA methodology among 71 individuals

Dr. Owen O'Shea holding a Caribbean whiptail stingray caught near Georgetown, Great Exuma.

Throughout aquatic environments, highly mobile predators are thought to serve as important vectors of energy between ecosystems thereby promoting stability and resilience. However, the role these predators play in connecting food webs and promoting energy flow remains poorly understood in most contexts. Using carbon and nitrogen isotopes, we quantified the use of several prey resource pools by 17 species of elasmobranch fishes i to determine their functional diversity and roles as ecosystem links.

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Although it is difficult to disentangle the effects of fishing mortality from other anthropogenic pressures on sharks, comparing shark abundance and diversity in jurisdictions with near zero fishing mortality versus prevalent shark fishing can demonstrate the role of overfishing. We used baited remote underwater video systems to compare shark abundance and diversity on coral reefs in 2 Caribbean nations with contrasting levels of shark exploitation: Belize (shark fishing) and The Bahamas (shark sanctuary).

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Anthropogenic stressors including overharvest, climate change, and pollution have been implicated in shifting ecology of nearshore and offshore marine ecosystems. Data on the ingestion of marine debris by highly migratory pelagic fishes of economic and ecological importance to the western North Atlantic Ocean is lacking. The objectives of this study was to quantify and categorize plastic debris i ingestion by pelagic sport fishes in The Bahamas.

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studying the tropho-dynamics of green turtles (Chelonia mydas) in a seagrass environment

This project aimed to provide high resolution information on the feeding behaviour of green turtles (Chelonia mydas). Specifically, we wanted to assess how interactions with top predators such as sharks impacted feeding behaviour and subsequent seagrass health from a large, tropical shallow embayment of the western Atlantic.

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Understanding the cultural significance of the black land crab fishery in the lives of island communities of The Bahamas

Understanding the cultural value and significance of any local fishery will underpin decisions on enforcing and managing resources that many island people have relied upon for generations. We interviewed human from several family islands to understand how perceptions of this fishery were culturally engrained, and how local knowledge reflected contemporary understanding of a valuable resource. 

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Out of sight, out of mind: An assessment into the biodiversity of an urban embayment from Eleuthera, The Bahamas

This community based project identified and catalogued plant and animal diversity from an urban embayment on the island of Eleuthera. We sought to provide insight among the local community into the value of seemingly inoccuous environment that are otherwise overlookd from conservation perspectives. 

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Impacts of ocean acidification on queen conch (Aliger gigas) growth and maturity

Increases in atmospheric carbon are destabilising pH balance in the oceans, leading to increased acidity which may lead to deleterious effects for animals that secrete calcium carbonate shells. Using a Bahamian iconic species, we hypothesised that by experimentally increasing ambient acidity, individuals tested would divert energy from maturation to shell reinforcement, possibly challenging the currently accepted metrics for assessing sexual maturity in this species, leading to broader ecosystem consequences. 

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A special thanks to
our collaborators...

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your contribution counts

Donations and gifts to our organization will directly contribute to fostering the next generation of environmental leaders, through the provision of resources critical in developing research education and engagement. Your support will cultivate and inspire a passionate community of students and citizen scientists dedicated to driving positive change in the preservation of our wild spaces.

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