This record provides an overview of the NESP Marine and Coastal Hub bridging study - "Future-proofing restoration & thermal physiology of kelp". For specific data outputs from this project, please see child records associated with this metadata. -------------------- For restoration to be effective, the cause of habitat decline must be understood and overcome. But this is problematic when climate change is driving habitat loss since it cannot be reversed or ameliorated prior to restoration. A previous NESP project led by this team (Project E7, Marine Biodiversity Hub) identified warmwater-tolerant strains of giant kelp from remnant patches in eastern Tasmania, where the species has experienced precipitous declines due to ocean-warming. These strains have high potential to assist with ‘future-proofing’ kelp forest restoration, however it is still unclear what the physiological mechanisms are that provide their improved thermal tolerance. This project is designed to better understand these physiological mechanisms to advance kelp restoration efforts in Australia and globally, and progress toward the identification of populations of Australian kelp that may be resilient to (or especially threatened by) ocean warming and climate change. Outputs • Ecophysiological measurements from laboratory experiments of warm-tolerant vs average giant kelp genotypes [dataset] • Final technical report with analysed data, including a short summary of recommendations for policy makers of key findings [written]

Intraspecific variation in the thermal tolerance of microscopic giant kelp (Macrocystis pyrifera) sporophytes was tested using a common garden experiment, where 49 unique family-lines were raised under four different water temperatures (12, 16, 20, and 24°C). The unique family-lines were taken from ongoing giant kelp gametophyte cultures held at IMAS, and represented F1 offspring from seven 'selfed' individuals collected from 6 sites across ~250km in Tasmania, Australia, in addition to a site-level cross from each of the sites, and a panmictic cross using the 42 pure family lines. Survivorship of the selected warm-adapted family-lines after outplanting trials at restoration sites can be found here with the associated dataset "NESP Marine Hub Project E7 outplanted kelp survivorship". https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/908afd8c-cc7a-4ea3-a87e-4497ae8da87a