Ensemble modelling of Indo-Pacific bottlenose dolphin(Tursiops aduncus) in Jeju waters

Abstract

Increasing human activity along the Jeju coast has amplified the extinction risk of inshore Indo-bottlenose dolphin, Tursiops aduncus. In this study, we applied an ensemble species distribution modelling approach, combining results of four modelling algorithms to identify areas of high probability of occurrence of the globally vulnerable dolphin in Korea. Model outputs were based on sighting data collected during boat and land based surveys between 2008 and 2017, and in relation to various ecogeographic variables. A total of 4 static variables were collected: distance to the coast, distance to the land-based aquaculture, distance to locations of the set net for fisheries and wind turbines on the Jeju waters. In addition, 2 dynamic variables were included in the model: sea surface temperature and chlorophyll were derived from MODIS. Shallow and coastal waters identified here should be considered priority areas for the conservation of this species. Our study demonstrates an evidence-based application toward managing habitat of Indo-Pacific bottlenose dolphin. Our predictions identify priority areas for dolphin conservation and for the implementation marine spatial planning and regulation.