Are corals coming to a reef near you? Projected extension of suitable thermal conditions for hard coral communities along the east Australian coast

Abstract

AbstractClimate change is driving the poleward redistribution of coral species, but the rate and magnitude of future range extensions within temperate regions are rarely quantified. A better understanding of the likely future distribution of corals is needed to anticipate the resulting social, economic and environmental implications. Here, we project the rate and magnitude of extensions of suitable thermal conditions for hard coral communities along the east Australian coastline, using data on coral community presence, in conjunction with historical and projected ocean temperatures. Our projections indicate that temperatures will be suitable for coral communities dominated by the subtropical coral Pocillopora aliciae, currently found off Sydney, to extend their range poleward by 80 (RCP 2.6) to 450 km (RCP 8.5) by 2100, corresponding to a rate of 0.9–5.0 km year−1. Similarly, thermal conditions will be such that diverse coral communities, such as those currently occurring in the Solitary Islands, may extend their range by 130 (RCP 2.6) to 580 km (RCP 8.5) by 2100, at a rate of 1.4–6.4 km year−1. These projections are similar to those forecast for coral species in other parts of the world. Newly establishing coral communities in temperate regions may provide a range of novel local economic opportunities, particularly for marine tourism.