Kelp forests are among the most productive and biodiverse coastal ecosystems, providing habitat for numerous species and supporting fisheries vital to coastal communities. These ecosystems are under severe threat from marine heatwaves, gradual ocean warming and predator loss, which has allowed urchin populations to devastate kelp beds. Across British Columbia and North America, kelp forests have experienced rapid declines or complete collapse. While interest in restoration is high, progress has been hindered by a lack of genetic knowledge about kelp in BC.

The KelpGen project filled this gap by creating genomic resources for bull kelp and giant kelp, the two most important kelp forest species in BC, including generating high quality reference genomes for both species. The reference genomes provide a comprehensive DNA blueprint and a resource for future research on kelp adaptation to warming waters.

Researchers sequenced hundreds of kelp individuals from across the coast, revealing genetically distinct regional groups and assessing population health. Insights from the use of these resources will help guide decisions about seed collection and movement for restoration and aquaculture. As an example, the team found that kelp often persists in small, inbred populations. They then examined how inbreeding affects the kelp genomes, leading to recommendations about how to incorporate optimal strategies for sourcing and crossing kelp strains into existing restoration and aquaculture methods.

 The project also explored patterns of local adaptation and identified candidate genes linked to climate adaptation. These findings could enable the selection of naturally occurring kelp strains predicted to thrive in warmer conditions, which could be deployed in restoration work to help kelp populations evolve to face rapidly changing climates.

Overall, the KelpGen project provided the genomic knowledge and resources to:

• Manage and restore kelp ecosystems so they can survive future challenges.
• Support future studies on kelp genomics and how it adapts to its environment.