Bottlenecks to seed-based seagrass restoration reveal opportunities for improvement

Habitat restoration is becoming an increasingly prevalent tool in the armoury of marine conservation, particularly given the expanding interest in creating nature-based solutions to a changing climate. Seagrass restoration is a particular focus of increased numbers of projects and although there is a growing number of examples of successful seagrass restoration attempts, there remain extensive case studies of poor success or restoration failure from around the globe. To enable marine habitat restoration to happen at scale and make a genuine contribution to carbon sequestration rates globally, improved methods that are both practical and simple are required to foster higher rates of success and lower costs. Here, we present seven bottlenecks to achieving reliable seed-based seagrass restoration. In doing so, we also provide opportunities for practical and simple ways in which the knowledge gaps that underpin these bottlenecks can be filled. Seed collection needs to be easier and more efficient; the processing and storage of seeds more controlled; and germination and seedling survival more effective so that fewer seeds are required for more reliable planting. We conclude that further collaborative multidisciplinary science is required in all parts of the world to improve seagrass seed-based restoration through better incorporation of faunal and microbial ecology, more reliable modelling, improved reporting of restoration failures and a wider investigation of seed-based ecology beyond a handful of species.