The creation of artificial islands through engineering is expanding globally for a variety of natural and socio-economic reasons. Historically, islands have been created to develop new airports or high-value properties, often filling wetlands or building on top of coral reefs. Today, project managers are dredging sediments from the near shore to construct luxury islands with marinas, offshore military bases in the middle of the ocean, wetland restoration projects, and rookeries for migratory birds. Potentially negative ecological effects of these activities include increasing turbidity in the water column, interrupting littoral sediment flow, and increasing vulnerability to extreme coastal storms or tsunami events. Still, novel aquatic and terrestrial habitats have been created and a relevant question is whether island biogeographic principles apply to these novel ecosystems. Based on island biogeography, we expect novel islands to have low species diversity given their short time since creation, and assist in the spread of exotic species by providing a locus for dispersal.
Results/Conclusions
The types of natural environments created by artificial island construction are generally marginal in spatial extent and squeezed between heavy development and the sea. These islands have lower topographic diversity and fewer land cover types, as compared to longer-established islands. Novel habitats have been created in spaces and oceanic basins where they did not formerly exist, for example hard structure habitats for crustaceans, fish, and mammals. Beaches have differing grain sizes and composition, with novel invertebrate community assemblages. Refugia for birds or other organisms have been created. Still, the sustainability of artificial islands will be challenged by extreme events and relative sea level rise. Hybrid engineering and ecological practices will have to be developed in order to address these challenges and take advantage of the opportunities.