PROJECT HIGHLIGHT
This project investigates thermal tolerance across six kelp species to understand how these marine communities might respond to rising ocean temperatures, while establishing seed banks of heat-tolerant individuals for future restoration efforts.
PROJECT SUMMARY
More frequent and intense El Niño events and marine heat waves continue to threaten kelp forests globally. The impacts are likely to be felt particularly strongly in Southern California, which constitutes the geographical limit for kelp forests in the US, meaning that kelp populations in this area already experience higher temperatures than kelp populations elsewhere in the country. This project investigates the effects of thermal stress at the cellular and organismal levels for six kelp species, assessing differences in thermal tolerance between populations and how this might be reflected in their genomes.
The research team has made significant progress in understanding how kelp species respond to warming ocean conditions. They have established monitoring programs across six sites in the La Jolla kelp forest to track changes in seaweed community structure over time in relation to temperature fluctuations. A key achievement has been the establishment of primary gametophyte cultures from 80 individual giant kelp plants from five La Jolla kelp forest sites, maintained in both active seed banks and dormant germplasm banks for long-term preservation. The team has also expanded their work to study six key understory kelp taxa, with gametophyte cultures established from three thermally distinct regions in San Diego. Complementary research has revealed that collection site and average water temperature correlate with spore survival, with spores from warmer locations showing better survival at higher temperatures.
The project incorporates both genetic analysis and field restoration components. Approximately 170 giant kelp DNA samples have been collected across San Diego kelp forests, with development of a reference genome to characterize genetic diversity. In preparation for experimental restoration, the team has identified three degraded sites in North La Jolla for outplanting and is developing specialized ceramic tiles to optimize kelp attachment and growth. The project works with Coastal Defenders, a grassroots Indigenous environmental organization, to co-create a kelp internship program within their Indigenous Leadership Youth Program, conducting knowledge exchanges with local Indigenous youth on Kumeyaay Territories. The results will be of direct use for resource managers trying to restore kelp in areas exposed to high ocean temperatures due to El Niño events and future marine heat waves.
MEDIA LINK
BBC "Restoring California's underwater forests"