📸: Fernando Lessa, Kelp Rescue Initiative.
Authors: Lauren Dykman, @claysteell.bsky.social, Jordan Bemmels, Grace Melchers, @scuba-timmer.bsky.social , Gregory Owens, Chris Neufeld, & @baumlab.bsky.social

While there remains some uncertainties and survivorship still remains low due to factors like grazing and swell displacing the outplants, these findings highlight modest enhancements to restoration success in regions of warming ocean.

We also found that creating cultures from a larger number of parents decreases self-fertilization rates but doesn’t necessarily result in better restoration outcomes. However, the long-term consequences of low genetic diversity in culture stocks used in restoration are unclear.

Overall, we found limited evidence for local adaptation to thermal microclimates, and that kelp sourced from warm sites sometimes performed worse than kelp from cold sites and may be maladapted to their environment. Sourcing kelp from colder sites may improve restoration outcomes in warming regions.

We also grew kelp from gametophyte “seed stocks” sourced from either 2 or 10 parents to explore how genetic diversity affected the success of kelp in these warm sites.

We grew giant kelp from warm and cold populations within a small geographic region in Barkley Sound, and performed a reciprocal transplant, moving warm populations to cold sites and cold populations to warm sites to explore whether giant kelp are locally adapted to their conditions.

Increasingly warming oceans threaten kelp forests worldwide. Where kelp forests have been lost, scientists, First Nations, and community members seek to restore lost kelp habitat. But how do you restore kelp forests when temperatures keep getting hotter?

In this work, led by Dr. Lauren Dykman and published in Restoration Ecology, we experimentally tested the roles of local adaptation and genetic diversity on the restoration success of giant kelp.