Dense, giant kelp (Macrocystis pyrifera) forests were once ubiquitous off Tasmania, but now only five per cent remain and they are listed by the Australian Government as an endangered marine community: the first such listing for Australia. The decline is associated with the increased presence off Tasmania of warm and nutrient-poor waters brought by the East Australian Current. Active restoration is a potential approach to the conservation of giant kelp forests, and efforts are focussed on the few remnant individuals.
This research extends a project begun in 2018 by the University of Tasmania to select for thermally tolerant and low-nutrient-tolerant giant kelp genotypes and examine effects of acclimation of selected genotypes by pre-exposure to warm, nutrient-poor conditions. Pre-exposed selected genotypes of giant kelp are being out-planted off eastern Tasmania as micro-sporophytes in an experiment with and without added nutrient. The work will assess the feasibility of this approach as a means to develop minimum patch sizes for giant kelp that can be self-replacing and self-expanding, thus providing restoration and future climate-proofing options for this EPBC-listed marine community.