Kelp forests dominate coastal environments in temperate and subpolar latitudes around the world and, much like terrestrial forests, create complex habitats that support diverse and productive food webs. In Australia, kelp forests are the foundation of the Great Southern Reef, a continental-scale temperate reef system that sustains high levels of biodiversity, endemism, and productivity. Kelp forests in Australia support numerous species of conservation and economic importance, including weedy seadragons, grey nurse sharks, rock lobsters, and abalone. The commercial and social benefits of kelp forests are also substantial, especially in coastal communities, and include indirect effects on commercial and recreational fisheries (e.g. effects on prey species and coastal food webs), ecotourism, and other forms of marine recreation (e.g. scuba diving).
Images credits: above, Craig Sanderson, left, Cayne Layton
Unfortunately, kelp forests in many locations around Australia and in other parts of the world are experiencing habitat loss due to climate change, overgrazing from herbivores, coastal development and pollution. Dense giant kelp (Macrocystis pyrifera) forests were previously a conspicuous and iconic feature of the Tasmanian coast, but loss of ~95% of these giant kelp forests over the past several decades has seen them listed by the Australian Government as an endangered marine community – the first such listing for a marine community in Australia. The decline of giant kelp forests in eastern Tasmania is associated with increased influence of warm and nutrient-poor East Australian Current water.
Image, above, healthy kelp forest (left) and a degraded kelp forest (right) in Tasmania. Photo credits: Adam Obaza (left), Matt Doggett (right)
Active restoration of these degraded and disappearing habitats represents a potential approach for conservation of giant kelp forests. Moreover, the same techniques that underpin restoration may be able to facilitate development of giant kelp permaculture for commercial harvest and integrated multi-trophic aquaculture. Currently, remnant and physiologically healthy individuals of giant kelp occur in eastern Tasmania where there used to be dense forests. Thus, there appear to exist thermally tolerant giant kelp individuals that may provide opportunity for restoration and permaculture.
This project – in collaboration with the Climate Foundation as part of their work to regenerate food security, ecosystem services and mitigate the effects of climate change – aims to establish whether there is the possibility of restoring Tasmania’s giant kelp forests by identifying individual giant kelp that may be better adapted to warmer sea temperatures. This pilot project is a necessary ‘Phase I’ of a potential larger project and aims to assess the potential for future up-scaling of restoration and Marine Permaculture efforts and fill critical knowledge-gaps to provide scientific rigour and risk-management in these efforts.
(Video, below: Professor Craig Johnson talks about the giant kelp restoration project)
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