Monitoring shallow coral reef exposure to environmental stressors using satellite earth observation: the reef environmental stress exposure toolbox (RESET). Issue 6 (30th May 2022)

• Record Type: Journal Article
• Authors: Williamson, Michael J.; Tebbs, Emma J.; Dawson, Terence P.; Thompson, Henry J.; Head, Catherine E. I.; Jacoby, David M. P.
• Editors: Scales, Kylie; Monk, Jacquomo
• Is Part Of: Remote sensing in ecology and conservation. Volume 8:Issue 6(2022)
• Page Start: 855
• Page End: 874
• Publication Date: 2022-05-30
• Subjects: Bleaching -- coral reef -- environmental stress -- Google Earth Engine -- remote sensing -- satellite; Remote sensing -- Periodicals; Ecology -- Research -- Periodicals; Ecology -- Methodology -- Periodicals; Ecology -- Remote sensing -- Periodicals; Nature conservation -- Methodology -- Periodicals; 577.0723
• DOI: 10.1002/rse2.286
• Languages: English
• ISSNs: 2056-3485

Abstract

Abstract: Coral reefs are significantly threatened by multiple environmental stressors associated with climate change. While there is growing recognition of the importance of interacting stressors on coral reefs, so far this has been primarily limited to in situ studies. Satellite remote sensing has potential for investigating coral reef exposure to multiple environmental stressors at a global scale over multiple years; however, current satellite monitoring is primarily focused on thermal stress. Here we collate nine environmental variables (cloud cover, current, depth, salinity, wind, and four sea surface temperature‐based metrics) from readily available satellite datasets using the Google Earth Engine geospatial processing platform. Using ecological and health‐based thresholds obtained from the literature, we developed, using fuzzy logic (discontinuous functions), a Reef Environmental Stress Exposure Toolbox (RESET) for monitoring environmental stress exposure at multiple scales. Stress exposure scores for 3157 reefs were generated and mapped globally across 12 coral reef ecosystem regions. RESET was also applied to three case‐study reefs, previously well monitored for stress and disturbance using other methods. PCA analysis indicated that depth, current, sea surface temperature (SST) and SST anomaly accounted for the greatest contribution to the variance in environmental stress exposure in these three regions. Depth, degree heating weeks, and SST anomaly were identified as the potential drivers of inter‐ and intra‐region variation in environmental stress exposure. Individual variables were then integrated into a multi‐metric index of combined stress exposure which corroborated temporal and spatial differences due to known disturbance events. RESET provides a open access, easily interpretable set of tools and associated indices for monitoring environmental stress exposure on coral reefs, designed to inform conservation and management decisions. As such RESET has broad potential to assist in the monitoring of our increasingly imperilled coral ecosystems, in particular, those that are remote or inaccessible. Abstract : There is growing recognition of the importance of analysing the impacts of interacting stressors on coral reefs, but so far this has been primarily limited to in situ studies. Satellite remote sensing has potential for investigating coral reef exposure to multiple environmental stressors over large spatial and temporal scales; however, current satellite monitoring is primarily focused on thermal stress. In this study, we collate nine environmental variables from readily available satellite Earth Observation datasets using the Google Earth Engine geospatial processing platform and develop the Reef Environmental Stress Exposure Toolbox (RESET) for remotely monitoring coral reef exposure to environmental stressors and at multiple scales.The RESET provides a freely‐available, easily interpretable set of tools and associated indices for monitoring environmental stress exposure on coral reef systems designed to inform conservation and management decisions.