Coastal Changes Over the Past 200 Years Around Ovalau and Moturiki Islands, Fiji: Implications for coastal zone management

Abstract

The islands Ovalau and Moturiki in central Fiji are selected for the investigation of coastal change over the past c. 200 years. Although having coastal environments typical of many tropical Pacific Islands, Ovalau and Moturiki are also atypical because they experienced urban and infrastructural developments before most other parts. The associated records enable recent coastal changes to be discerned more clearly here than has been possible elsewhere. The islands are surrounded by coral reef, the configuration of which accounts for variations in vulnerability of their coasts to erosion. Interviews were conducted in each of 22 settlements along the islands' coasts and information obtained about recent coastal change. Mangroves are concentrated along leeward coasts, although they have been cleared from many windward coasts in the last 40 + years, causing shoreline erosion to be initiated/accelerated. Most shoreline-protection initiatives (vegetation planting and seawall construction) have failed. Three major management implications of the study are discussed. Firstly, there is a need to redefine the nature of the interactions between coastal inhabitants and coastal ecosystems, so that environments are sustainably developed; and specifically that reefs are conserved and shoreline vegetation (especially mangroves) is effectively replanted. Secondly, information about appropriate design and composition of artificial structures for shoreline protection needs to be made available to the local communities who construct most of them. Thirdly, alternative sources of sand and rock aggregate to those whose extraction aggravates shoreline erosion should be sought.