Joint NOAA – CCMI research monitors environmental conditions on Little Cayman’s coral reefs to understand coral resilience and improve the accuracy of NOAA’s bleaching forecasts.

LITTLE CAYMAN ISLAND – A joint effort between NOAA and the Central Caribbean Marine Institute (CCMI) is underway to improve understanding of how local variations in temperature and light conditions may affect the ability of corals to survive environmental impacts, such as coral bleaching, as well, as well as determine how accurately NOAA’s satellites are able to identify coral bleaching based on sea surface temperatures.

Corals bleach when environmental conditions such as water temperature become stressful for the corals and they expel the symbiotic algae which provide corals both food and color. “Excessively warm waters lead to coral bleaching, but not all corals bleach at the same time or same rate,” says NOAA scientist Dr. Karsten Shein, the lead investigator of the study. “One reef might experience severe bleaching while another reef just a kilometer away is largely unaffected. We need to know why that is if we want to help preserve our reefs.” One possibility is that localized subsurface conditions such as upwelling may protect corals from excessively high water temperatures experienced closer to the surface. Another is that variations in light, on which the symbiotic algae depend for photosynthesis, can provide the needed resistance to bleaching.

Unfortunately, satellites, which provide the estimates of water temperature used in coral bleaching alerts, only capture the surface temperature, and in clear, shallow water can be affected by factors such as reflections from the seabed. To address these issues, Dr. Shein from NOAA’s National Centers for Environmental Information (NCEI), Miranda Camp, a Research Experience for Undergraduates (REU) student from Stetson University, and the CCMI staff at the Little Cayman Research Centre have installed a series of instrument profiles around Little Cayman Island. These profiles, provided by NOAA’s Coral Health and Monitoring Program (CHAMP) are moored in the sand adjacent to 6 different reefs (Grundy’s Gardens, Martha’s Finyard, Mixing Bowl, Snap Shot, Blacktip Tunnels, and Coral City), and suspended by an orange buoy. Instruments at 3 depths (sea surface, mid-column, and seabed) gather 15-minute temperature and light data which will be analyzed against both coral vitality on the reef as well as satellite-based sea surface temperatures. The profiles will remain anchored around Little Cayman Island for one year. “As a result of this study,” says Dr. Shein, “we hope to greatly improve satellite-based forecasting of coral bleaching as well as develop approaches that will improve the ability of the Cayman Islands and elsewhere to monitor and manage reef health.”

Funding for Miranda Camp’s participation in the Little Cayman REU programme is provided by the National Science Foundation’s Division of Ocean Sciences located in Arlington, VA and private donations to the UK and US CCMI Research Fund.

Founded in 1998, the Central Caribbean Marine Institute (CCMI) is guided by its mission to conduct and facilitate research, education, outreach and conservation programmes that will sustain marine biodiversity for future generations. The organization is incorporated as a US 501(c)3 non-profit organization (ID# 22-3609293), a UK charity (# 1104009) and a Cayman Islands non-profit organization. In 2006, CCMI built the Little Cayman Research Centre, a premiere establishment for conducting tropical marine research and education programmes. Little Cayman harbours some of the most biologically diverse reef systems on earth. The island therefore affords rich opportunities for studies to address global issues such as climate change, marine protection, fisheries management and coral reef stress.

IMAGES:

Dr. Karsten Shein (NOAA) and REU student Miranda Camp install a temperature and light instrument profile in the sand near Martha’s Finyard in Little Cayman.

Temperature and light data logger. Data are collected every 15 minutes and can be downloaded underwater with a special shuttle. The logger can store data for 300 days between downloads.