The effects of urbanisation on coastal habitats and the potential for ecological engineering: a Singapore case study

Habitat loss associated with land reclamation and shoreline development is becoming increasingly prevalent as coastal cities expand. The majority of Singapore's mangrove forests, coral reefs and sand/mudflats disappeared between the 1920s and 1990s. Our study quantifies additional coastal transformations during the subsequent two decades, analyses the potential impact of future development plans, and synthesises the mitigation options available. Comparisons of topographical maps between 1993 and 2011 reveals declines in total cover of intertidal coral reef flats (from 17.0 km² to 9.5 km²) and sand/mudflats has (from 8.0 km² to 5.0 km²), largely because of extensive land reclamation. Conversely, mangrove forests have increased (from 4.8 km² to 6.4 km²) due to restoration efforts and greater regulatory protection. However, 15 and 50-year projections based on Singapore's 2008 Master Plan and 2011 Concept Plan show that all habitats are predicted to shrink further as new reclamations are completed. Such decline may be counteracted, at least in part, if ecological engineering is used to help conserve biodiversity. The problems exemplified by Singapore, and the potential future solutions discussed in our paper, provide guidance for urban marine conservation in coastal cities that are experiencing rapid development and land use change.