Coastal Ecology of the Bahamas
The Bahamian archipelago is a unique ecosystem, constituting 700 islands and 2000 cays in the northeast Caribbean Sea. Tourism is a major industry in the Bahamas, depicted as an exotic paradise because of the sandy beaches, turquoise seas and tropical weather. However, due to the small size of the islands and their ecology, there are limitations to the level of development that can occur without irreversible environmental changes occurring.
Historical activities have had major impacts on the coastal zone of the islands, such as tourism developments (failed and successful), the introduction of invasive species, and old U.S. military bases. For example, military activity has resulted in dredged marinas, filled mangrove forests and removal of dunes along the coast of Andros Island, with only a fraction of the altered landscape in use today. On Long Island, the Diamond Crystal Salt Works, abandoned more than 20 years ago, have left approximately 4,000 acres of coastal wetland destroyed.
The hypothesis behind the project is that coastal development increases movement of nutrients and pollutants from the land into the sea. This impacts the diversity of near shore marine habitats, in turn decreasing the integrity of these habitats and, for example, their ability to support important fisheries populations. In short, human activities in the coastal zone of small islands take a heavy toll on ecosystem health.
The aims of the project
The project is studying four main objectives. The first is development of a model to predict the potential biological diversity and fisheries production of Bahamian coastal marine communities. The second is collection of data on water quality and marine plants to test models estimating pollution levels and nutrient movements in the marine environment. Thirdly, the project is evaluating the extent of ecological impacts on water quality and marine plant communities from both chronic (long-term) or acute (catastrophic) events. Finally, the project is testing remediation strategies for destroyed and degraded habitats through coastal restoration projects, all planned in co-operation with local communities.
Dr Kathleen Sullivan-Sealey, currently Dean of Pure and Applied Sciences at the College of The Bahamas, and Associate Professor of Biology at the University of Miami, has been working with Earthwatch in the Bahamas since 1985. She started focusing on coastal ecology in 2000, when this project was born. Nearly 250 Earthwatch volunteers have joined the project to date, based on six of the islands - Abaco, Andros, Eleuthera, Great Exuma, Great Inagua and Long Island. Volunteers are taught all the skills they need to carry out project activities such as shore profiling, snorkel surveys, impact assessments and interviews. Volunteers also help with practical tasks such as dune restoration and construction; and installation and subsequent monitoring of artificial reef units. In 2008, the Inagua islands were hit by Hurricane Ike, which was devastating to Matthew Town, the largest settlement on the island. A major reconstruction effort is now taking place and Earthwatch teams this year have been exploring the coastal impacts of this storm.
The scientists and volunteers quickly discovered that each major island group has a unique ecology. Since 2002, more than 430 coastal sites have been surveyed, classified and ranked for anthropogenic, or human-caused, impacts. This resulted in production of a State of the Coast report in 2009 that will be vital for future strategies regarding the health of the nation's environment and economy. Knowing the differences among coral reefs around the northern islands, in terms of species diversity and abundance, is vitally important for enabling development of effective environmental regulations and planning for protected areas. Additional research comparing existing baseline data (knowledge of the status of the marine environment from previous surveying) with data from continual monitoring, has led the scientists to discover that in coastal areas subjected to high levels of human activity, the impacts of hurricanes and storms are more severe, and marine ecosystems take longer to recover.
Progress in 2008
In 2008, Earthwatch scientists and volunteers carried out coastal restoration projects, helping with dune restoration and removal of invasive Australian pine trees from 93 acres of coastal zone on Guana Cay, Abaco, and constructing artificial reef units to replace patch reef habitat removed in the initial development of the area in the 1980s. After installation, teams conducted fish surveys, fish tagging, and surveys of coral and epifauna (animals living on the coral) to monitor progress and development of the patch reefs. They also established a native plant nursery, removed invasive plant species from a nature trail, and transplanted threatened plants from areas under development.
A key recommendation from the project is to start local environmental education initiatives. If guided, local groups can have an important impact on environmental management and raising awareness. Therefore, the project works with the Exuma Education Resource Foundation (EERF) on activities such as developing nature trails and educational outreach for schools, and running a "Native Plant and Plant Communities" course for residents. It also supports long-term monitoring of water quality in Elizabeth Harbour for the local government and harbour management committee.
In 2008, the researchers teamed up with a development company to guide construction of a sustainable tourist resort in the Abaco Islands. This new collaboration with planners, developers and engineers required them to rethink what ecological and geological information was needed for construction on an island - such information and ideas that ecologists take for granted are not regular considerations for developers. The following findings from the project will help with making environmental recommendations for development in the future:
- Environmental programs constituted 15 per cent of the total budget - but have long-term benefits;
- Tourism development in The Bahamas must look for sustainable alternatives to meet water demand, due to limited fresh water resources on the islands;
- Coastal buffer zones and private reserves (especially small wetlands) are important to incorporate as protection from floods and storms, as well as to meet environmental goals and reduce costly mitigation projects. Such coastal setbacks are also necessary to reduce beach erosion;
- Restoring functional landscapes is critical in new developments to maintain minimum population thresholds of local species;
- Land-based pollution must be reduced.
For the future, in order to restore coastal fish habitat and the health of fisheries around the islands, more major mitigation projects need to be carried out. Long-term sustainability of development will depend on careful attention being paid to the impacts of flooding and storm events, and efforts to minimize property damage - all the while protecting coastal resources and shoreline stability. Over the next three years, the Earthwatch project will develop major initiatives such as coastal restoration at Elizabeth Harbour, Great Exuma, restoring and monitoring coastal wetland and lagoon systems impacted by the Diamond Crystal Salt Works on Long Island, and establishing criteria for coastal setbacks and buffer zones for all coastal habitat types. The Victoria Pond Restoration Project has already begun in George Town, Great Exuma, to improve environmental stewardship and the function of the landscape to enhance tourism, fisheries and quality of life.
If you would like to be involved as a volunteer, read more about the Earthwatch expedition Coastal Ecology of the Bahamas.
Report by Debbie Winton.