By Meredith Albury
Whether you live here or are just visiting, you probably have seen first hand the beauty of Abaco’s reefs and how they are teeming with life. But how healthy are these reefs? What can we do to ensure protection of these valuable ecosystem services, such as fishery support and shoreline protection?
The Perry Institute for Marine Science is leading an effort to evaluate the health of Abaco’s coral reefs to answer these questions, and develop strategies to ensure their survival. This effort is part of ‘The Reversing the Decline of Bahamian Coral Reefs’ program, led by the Perry Institute with support for research on Abaco’s reefs.
This is provided by the Devereaux Ocean Foundation, Atlantis Blue Project Foundation, and Disney Conservation Fund. Around Abaco, the project will be done in partnership with Friends of the Environment, and local dive shops as well as other Bahamian partners like the Bahamas National Trust, Cape Eleuthera Institute, Department of Marine Resources, and international partners such as Secore International, the Shedd Aquarium, The Nature Conservancy, Middlebury College and the University of Miami.
The first phase of the project involves a study of coral reefs throughout the Abacos. Last month, students and faculty from Middlebury College joined Dr. Craig Dahlgren, Executive Director of The Perry Institute for Marine Science, to kick off this year’s coral reef assessments.
According to Dr. Dahlgren, “the coral reef assessments will let us compare the health of reefs here to other parts of The Bahamas and Caribbean, and provide a roadmap to determine how we can help build their resilience to various threats, protect them from further damage from local issues, and even jump-start the recovery process by restoring key coral species to reefs.”
Preliminary data indicate that while Abaco’s reefs have suffered declines in health, many are still in relatively good shape. Mermaid Reef has proven to be relatively healthy, even though temperatures there get below the threshold that most corals can tolerate in the winter, and often experience high temperatures that would kill most corals in the summer.
Reefs like this may be the key to figuring out coral survival in the face of climate change. Along with Dr. Dahlgren, coral biologists Dr. John Parkinson of Secore International, Dr. Ross Cunning of the Shedd Aquarium in Chicago, Dr. Erin Eggleston, and Dr. Jeremy Ward of Middlebury College took small genetic samples from colonies on these reefs to examine how these corals may be uniquely adapted to thrive in these conditions. Tagged corals will be monitored over time and studied further in the second phase of the research program.
The second phase of the program includes reef restoration, where fragments of critically endangered elkhorn and staghorn coral will be grown and harvested periodically and attached to reefs to repopulate them. Coral spawn will also be collected and fertilized in the lab to increase reproductive output for specific coral colonies.
Larvae can then be grown in enclosures near the reef until they settle to specially designed structures and grown to the point where they can be used to “reseed” reefs. By selectively fertilizing eggs from resilient coral strains like those of Mermaid Reef, scientists hope to give corals a better chance to survive unusually high temperature that has killed so much of our corals over the past 20 years. Dr. John Parkinson explained “These corals are uniquely hardy, withstanding chilling cold in winter and extreme heat in summer. But they’re also isolated, so their genes aren’t passed on very often. We want to help them breed with other corals in Abaco so future generations will be more tolerant of temperature stress.”
Dr. Dahlgren also cautions that while it is an important strategy for corals, restoration can only go so far, saying “While corals are the foundation that build the habitat that so many species, including our own, rely on, coral reefs require a delicate balance of species – parrotfish and urchins that graze seaweed from reefs; grouper, snapper and crawfish that can control species of fish and other creatures that consume or kill coral; and even sponges and sea cucumbers that help cycle nutrients on reefs.” Reef surveys conducted this year will also be used to make recommendations for the management of parks and key fishery species on reefs around Abaco to maintain healthy coral reef ecosystems that continue to provide us with valuable ecosystem services and keep their incomparable beauty.
For more information on this program or coral reefs of The Bahamas, please visit www.perryinstitute.org or contact local partners such as the Bahamas National Trust, Friends of The Environment or the Department of Marine Resources. A full report on the condition of coral reefs of Abaco and other parts of The Bahamas will be completed later this year and made available through the Perry Institute for Marine Science.