Validation of Reef-Scale Thermal Stress Satellite Products for Coral Bleaching Monitoring

Scott Heron,Jeffrey Maynard,William Skirving,David Benavente,Jacqueline De La Cour,C Eakin,Alan Strong,Steven Johnson,Gang Liu,Ryan Okano,Denise Perez,Kyle Tirak,John Iguel,Erick Geiger,Timothy Burgess,Lyza Johnston

doi:10.3390/rs8010059

Abstract

Satellite monitoring of thermal stress on coral reefs has become an essential component of reef management practice around the world. A recent development by the U.S. National Oceanic and Atmospheric Administration’s Coral Reef Watch (NOAA CRW) program provides daily global monitoring at 5 km resolution—at or near the scale of most coral reefs. In this paper, we introduce two new monitoring products in the CRW Decision Support System for coral reef management: Regional Virtual Stations, a regional synthesis of thermal stress conditions, and Seven-day Sea Surface Temperature (SST) Trend, describing recent changes in temperature at each location. We describe how these products provided information in support of management activities prior to, during and after the 2014 thermal stress event in the Commonwealth of the Northern Mariana Islands (CNMI). Using in situ survey data from this event, we undertake the first quantitative comparison between 5 km satellite monitoring products and coral bleaching observations. Analysis of coral community characteristics, historical temperature conditions and thermal stress revealed a strong influence of coral biodiversity in the patterns of observed bleaching. This resulted in a model based on thermal stress and generic richness that explained 97% of the variance in observed bleaching. These findings illustrate the importance of using local benthic characteristics to interpret the level of impact from thermal stress exposure. In an era of continuing climate change, accurate monitoring of thermal stress and prediction of coral bleaching are essential for stakeholders to direct resources to the most effective management actions to conserve coral reefs.

Highlights

Global, near real-time satellite monitoring of environmental conditions linked to coral bleaching has supported coral reef management efforts for nearly 20 years
In this paper we introduce two new monitoring products developed within the 5 km DSS that support management efforts prior to, during, and after a bleaching event: Regional Virtual Stations and
Using these and other CRW products, we describe the development of thermal stress in Commonwealth of the Northern Mariana Islands (CNMI) (Figure 1a) during 2014; discuss how the CRW 5 km DSS was used to inform local managers and other stakeholders as stress developed; present data from in situ observations of coral bleaching during this event; and undertake the first quantitative comparison of the 5 km DSS products with observations of coral bleaching

Summary

Introduction

Near real-time satellite monitoring of environmental conditions linked to coral bleaching has supported coral reef management efforts for nearly 20 years Throughout this period, the U.S. National Oceanic and Atmospheric Administration’s Coral Reef Watch (NOAA CRW) program developed and released coral-specific satellite-based tools and successfully monitored thermal stress causing mass bleaching events around the world [1,2,3,4,5,6,7,8]. National Oceanic and Atmospheric Administration’s Coral Reef Watch (NOAA CRW) program developed and released coral-specific satellite-based tools and successfully monitored thermal stress causing mass bleaching events around the world [1,2,3,4,5,6,7,8] These products have been instrumental in aiding reef managers and other stakeholders to prepare for and respond to coral bleaching events. Mass coral bleaching events have been linked to warm oceanic temperature anomalies, which occur on the scale of hundreds to thousands of kilometers [10]

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