Canopy-forming seaweeds such as kelps provide the foundation for habitat in temperate shallow seas worldwide. In Australia, kelp-dominated temperate reefs have experienced steep declines coinciding with climate-driven increases in seawater temperature; the frequency of heatwaves; and the arrival of tropical herbivorous fish, which has dramatically increased consumer pressure on kelps. If kelp ecosystems are to survive running the gauntlet of climate change, we must find ways of preventing further declines. With that in mind, my thesis aims to i) explore novel approaches to increase their resilience to future stress and ii) improve our understanding of the mechanisms hindering their recovery once they have collapsed. Understanding how species respond to changing environmental conditions is critical for forecasting the future of coastal ecosystems and their functioning, on which human wellbeing depends.