Regional and local variability in coastal processes in Torres Strait, Australia, and its importance for climate change planning

In small island states or regions, climate change planning is frequently undertaken at a country or regional level, and it is assumed that problems are common and that remedial actions can be widely applied. Community members observe treatments such as seawalls elsewhere and demand similar interventions even though they may be inappropriate. Torres Strait lies between mainland Australia and Papua New Guinea and has communities on a diverse range of islands including low muddy, coral cay, volcanic and continental island types. Approaches to solving problems caused by changing coastal processes on these varied shorelines are discussed at scales from regional to specific sites. Torres Strait has two distinct wind seasons which influence wave-driven processes and lead to seasonally reversing alongshore sediment transport, with shoreline dynamics also controlled by coastal orientation and the beach / reef flat interactions. The low muddy islands have limited management options, requiring shore protection and elevation. Shorelines on coral cay islands and the volcanic and continental islands change shape seasonally. In these settings, planning must allow for the seasonal shoreline adjustments, with structural treatments to manage longer-term shoreline trends used only to protect high-value assets and important cultural sites where alternative management responses are not possible