Coral reef risk assessment using DMSP nighttime lights - Temporal trends and global perspectives

In this paper a global coral reef risk assessment is presented showing temporal trends related to human activity in close proximity to reef ecosystems. Based on the DMSPOLS (Defense Meteorological Satellite Program - Operational Linescan System) archive spanning the years 1992-2003 a time series analysis is carried out, whereas inter-calibration of the data derived from four different DMSP satellites guarantees inter-comparability of the results. A previously developed index measures the distance of reef sites to three chosen stressors and the stressor's intensity. The stressors all being likely to have adverse effects on coral reefs are distinguished and classified in the DMSP nighttime lights imagery: urban development, gas flaring, and heavily lit fishing boat activity. Results show a global trend of increasing risk in particular when referring to human settlements as reef stressor and can be of high interest for conservation and restoration activities as well as for global biodiversity concerns.