Coral reefs are one of Earth's most diverse ecosystems. They provide significant ecological, economic, and societal benefits valued, globally, at about USD$9.8 trillion each year (de Groot et al. 2012, Costanza et al. 2014). Unfortunately, reefs worldwide are threatened by an increasing array of impacts, primarily from global climate change, unsustainable fishing practices, and land-based pollution. First observed in the early 1980s, mass coral bleaching has become one of the most visible and damaging marine ecological impacts of persistently rising ocean temperatures. Bleaching is the process by which corals lose the symbiotic algae (zooxanthellae) that give them their distinctive colors and main energy sources. If a coral is severely bleached, disease and death become likely. Severe coral bleaching has become more extensive, frequent, and intense. This can be seen in the acceleration of heat stress events that cause mass bleaching, and in new multi-decadal bleaching observation datasets. As manifested by the devastating 2014-2017 global coral bleaching event (now considered the longest, most widespread and most damaging coral bleaching event on record), mass bleaching events around the globe are often lasting many months; are becoming an annual event; and are impacting coral reefs that never bleached before. It's clear that remote monitoring of coral reefs and the development of actionable intelligence are critical for early detection, on-the-ground response, communication, and future resilience planning to better protect these ecosystems from further degradation and loss.
In response to these concerns and management needs, and to enhance coral reef resilience in a warming world, NOAA established the Coral Reef Watch (CRW) program in 2000. For more than 20 years, NOAA CRW has utilized remote sensing, modeled and in situ data to observe, predict, and report to its users on the coral reef environment worldwide. CRW provides the only global early-warning system of coral reef ecosystem physical environmental changes. Its near real-time satellite products and modeled Outlook predictions have successfully and accurately monitored and predicted all major mass coral bleaching events observed globally since 1997, while also providing other critical information to users, especially during times of high oceanic heat stress. CRW's products help resource managers, scientists, decision makers (including elected officials), monitoring networks, and the public monitor climate impacts to reef ecosystems worldwide; better understand links between environmental conditions and ecosystem impacts; assess when reefs are vulnerable or resilient to climate change and its impacts (especially bleaching); and prepare and prioritize resources to implement timely, effective protective responses and adaptation actions (including restoration efforts), thereby improving the management and regulation of coral reefs in a warming world. Protective measures include reducing local stressors in times of high heat stress (e.g., by closing major scuba diving and fishing areas). CRW also informs multiple national and international assessments of coral reef conditions.
NOAA CRW is uniquely qualified to provide essential environmental intelligence. Its extensive partnership network with data providers, scientists, and coral reef managers allows CRW to leverage key partner efforts in the U.S. and internationally, to undertake research to develop the best possible products for its users, and to better understand how stakeholders use its tools. CRW works closely with its users throughout product conceptualization, development, implementation, and operationalization, providing training in appropriate product use, and garnering feedback to improve management tools. This places CRW at the forefront of providing services to improve understanding of climate change threats to coral reefs, and establishes sound practices for the use of its products to enhance resilience-based coral reef management.
CRW is part of the NOAA Coral Reef Conservation Program and the National Environmental Satellite, Data, and Information Service. A brief history of CRW's early years is featured in "NOAA Celebrates 200 Years of Science, Service, and Stewardship".
CRW's satellite product suites are a key component of NOAA's monitoring efforts for coral reef ecosystems, including the Coral Reef Conservation Program's National Coral Reef Monitoring Program.