Abstract

Urbanization of coastal cities has resulted in extensive physical modification of the coast that is commonly accompanied by habitat destruction or degradation, marine biodiversity loss and ecosystem services decline. Conversion of the natural environment to a human-modified one is often permanent, and it is important that development considerations take into account biodiversity enhancement of the ‘new’ environment. Development of biological communities in the modified environment takes time and is unlikely to return to levels once supported by the original habitats, but efforts can be made to facilitate the establishment of biodiversity that is suited to the new environmental conditions. Active interventions such as water quality management and ecological restoration can help to transform the urbanized coastal environment into a suitable biodiversity support zone. Observations of marine biodiversity in marinas and restoration of corals on artificial structures in Singapore support this prospect. Assessment of the biodiversity in three marinas indicated that they can function as marine biodiversity refugia, especially with their relatively high artificial structural complexity and when designed with basic ecological considerations to enhance marine biodiversity. Separately, reef restoration projects give rise to the possibility of colonizing seawalls with corals and other reef-associated species, as well as improving degraded reefs and creating reef communities in areas originally devoid of corals due to the heavy sediment load of urbanized coastal waters. Maintaining marine biodiversity in challenging environmental conditions resulting from urbanization can help to ensure continued provision of some level of ecosystem services.