Cayne Layton1,2, Eva Smid1, Masayuki Tatsumi1, Jeff Wright1, Craig Johnson1
1 Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
2 Centre for Marine Socioecology, University of Tasmania, Hobart, Australia
Kelp forests are the foundation of the Great Southern Reef, Australia’s continent-wide temperate reef system that supports high levels of biodiversity, endemism, and economic value. Unfortunately, in Australia and elsewhere, kelp forests are declining due to climate change, overgrazing from herbivores, and coastal development and pollution. Globally, some of the most dramatic declines have occurred in Tasmania, Australia, where 95% of giant kelp (Macrocystis pyrifera) surface canopies have disappeared since the 1950’s. Habitat restoration is one potential tool for kelp forest conservation, but critically, any restoration intervention must first address the ongoing challenge of climate change that continues to drive giant kelp loss.
Here we outline the key drivers of giant kelp forest loss in Australia – increasing water temperatures and reductions in coastal nutrients – and present a novel restoration approach using more warm-tolerant giant kelp genotypes. We summarise the results of experimental work that identified high intraspecific variation in thermal tolerance of Macrocystis in Tasmania, and provide an update on (ongoing) restoration field trials using those genotypes that exhibited increased warm-tolerance. We also briefly introduce components of the broader project looking at the physiology, genetics, and breeding of Macrocystis in Tasmania, and of kelp restoration decision-making. Ultimately, we aim to provide a foundation for future-proofing efforts to maintain and restore kelp forest resilience in a global ocean-warming hotspot, and to provide risk-management to habitat restoration in a rapidly changing climate.