Change Detection of Bunaken Island Coral Reefs Using 15Years of Very
Marine Pollution Bulletin xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Change detection of Bunaken Island coral reefs using 15 years of very high resolution satellite images: A kaleidoscope of habitat trajectories ⁎ Eghbert Elvan Ampoua,b,c, , Sylvain Ouillonc, Corina Iovana, Serge Andréfouëta a UMR9220 ENTROPIE, IRD, Université de la Réunion, CNRS, B.P.A5, 98848 Noumea, New Caledonia b Institute for Marine Research and Observation, Ministry of Marine Affairs and Fisheries, SEACORM/INDESO center, Jl. Baru Perancak, Negara-Jembrana, Bali 82251, Indonesia c Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (LEGOS), Université de Toulouse, IRD, CNRS, CNES, UPS, 14 avenue Edouard-Belin, 31400 Toulouse, France ARTICLE INFO ABSTRACT Keywords: In Bunaken Island (Indonesia), a time-series of very high resolution (2–4 m) satellite imagery was used to draw Indonesia the long-term dynamics of shallow reef flat habitats from 2001 to 2015. Lack of historical georeferenced ground- INDESO truth data oriented the analysis towards a scenario-approach based on the monitoring of selected un- Remote sensing ambiguously-changing habitat polygons characterized in situ in 2014 and 2015. Eight representative scenarios Reef flat (coral colonization, coral loss, coral stability, and sand colonization by seagrass) were identified. All occurred Marine habitat simultaneously in close vicinity, precluding the identification of a single general cause of changes that could Resilience have affected the whole reef. Likely, very fine differences in reef topography, exposure to wind/wave and sea level variations were responsible for the variety of trajectories. While trajectories of reef habitats is a way to measure resilience and coral recovery, here, the 15-year time-series was too short to be able to conclude on the resilience of Bunaken reefs.
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