Responding to a recent coral bleaching event in the Caribbean, a NASA-led team is in the region this week assessing the situation as part of a U.S. inter-agency response.
Coral bleaching is associated with a variety of stresses including increased sea surface temperatures. This causes the coral to expel symbiotic micro-algae living in their tissues – algae that provide corals with food. Losing their algae leaves coral tissues devoid of color, thus appearing to be bleached. Prolonged coral bleaching (more than a week) can lead to coral death and the subsequent loss of coral reef habitats for a range of marine life.
“Coral reefs are considered ‘canaries of the oceans,’ acting as an early warning system for marine ecosystems,” said Liane Guild, a scientist at NASA Ames Research Center, located in California’s Silicon Valley. Guild is leading the NASA emergency deployment to rapidly assess the damage before other changes take place in the affected reefs.
Warnings of the onset of this event were first reported by the NOAA Coral Reef Watch Satellite Bleaching Alert monitoring system in late August in the Florida Keys. News of these warnings spread throughout much of the eastern Caribbean in September and October. The U.S. Coral Reef Task Force called for the inter-agency response in November. The deployment will continue until Dec. 20.
“I’m very pleased to have NASA step up and bring its expertise and assets to help the scientific community understand and address this devastating event,” said Timothy Keeney, deputy assistant secretary of commerce for oceans and atmosphere. Keeney is the United States Coral Reef Task Force co-chair.
The NASA-led inter-agency team is inspecting reefs in Puerto Rico, including sites at La Parguera and Culebra Island. Sites in the U.S. Virgin Islands include Buck Island, the north coast of St. Croix and the south coast of St. John.
With financial and staff support from NASA, the National Oceanic and Atmospheric Administration (NOAA), the U.S. Department of Interior and other agencies, NASA is conducting aircraft fly-overs above the affected reefs to gather valuable data.
The team’s Twin Otter aircraft – supplied by Goddard Space Flight Center, Greenbelt, Md. – will inspect the bleached reef areas using a digital camera and the NASA Airborne Visible Infrared Imaging Spectrometer (AVIRIS), an instrument that captures visible and infrared light data. The aircraft-based sensors provide higher spectral and spatial resolution data and can be used to enhance understanding of ocean biology satellite data.
“The importance of this research is that we will be concentrating on aspects that enhance both understanding and prediction of reef status in terms of the extent of bleached corals, coral mortality, evidence of recovery, evidence of algal overgrowth and biodiversity using AVIRIS data and field measurements,” Guild said.
NASA, NOAA and other organizations also are supporting field monitoring to complement the flyover. Guild’s field team will be in the water when the overflights occur, collecting data on the coral that relate to the AVIRIS data.
Coral reefs are critical for marine fisheries, providing habitat and nursery grounds, according to experts. “The structure of coral reefs provides coastline protection from severe storms by dampening wave action,” Guild said. The research being done by the team that assesses the potential impact of a changing climate on global ecology supports federal U.S. Climate Change Science Program and U.S. Ocean Action Plan objectives.
The NASA-NOAA effort is just one component of the response. Many other efforts are underway to help document and track this bleaching event and its long-term impacts on Caribbean coral reef ecosystems and the communities that depend on them. The NASA-NOAA flights are one part of a larger interagency federal and international effort to document and assess the extent and impacts of this massive bleaching event as called for by the task force. More information about coral reefs can be found at http://www.coralreef.gov.
Other partners in this study include researchers from the University of Puerto Rico, NOAA’s Coral Reef Conservation Program and the National Park Service in the U.S Virgin Islands.
For more information about NASA and agency programs on the Web, visit: http://www.nasa.gov/home.
