Kelp forests are the foundation of Australia’s Great Southern Reef, and support critical ecosystem services and unique biodiversity. Unfortunately, these ecosystems are experiencing unprecedented and increasing stressors, largely driven by climate breakdown. Consequently, there is a growing urgency to actively manage and restore these environments. Simultaneously, Australia has a burgeoning seaweed aquaculture industry, much of which is focussed on native kelps. ‘Seedbanking’ – or more correctly for seaweeds, germplasm banking – is an emerging tool to help safeguard wild genetic diversity and support ongoing restoration and aquaculture activities. Here we describe our seedbanking of kelps across Tasmania, and demonstrate how this ~7-year old collection facilitates a diverse suite of ongoing work, including cultivation optimisation, stressor experiments, and strain selection. This living repository also serves as the foundation for critically important genetic conservation and research, and even supported emergency collections of threatened giant kelp populations prior to the forecast extreme marine heatwave of 2023/24. We are continually refining our methods to sustain the long-term viability and cost-effectiveness of storing these kelps for the years ahead. Ultimately, we aim to provide a model for other regions and seaweed species, and to contribute to global and collaborative conservation and biobanking efforts.