3.2 Database

The Kelp Forest Alliance maintains a global database of kelp forest restoration projects worldwide. It allows registered users to upload the outcomes of their restoration projects and contribute to the global tally. As of publication, there were 239 projects uploaded from 15 countries, and these entries were used to generate the report figures. While the database is inclusive of project types and countries of origin, it is currently only available in English, and results are biased as a result. The people and organisations related to this database are described in Chapter 5.

3.3 State of Kelp Restoration

Modern kelp restoration started in 1958 and has since seen ~19,000 ha (2% of the Kelp Forest Challenge) of kelp forest area restored (Figure 3.1). Most projects to date have been quite small in area, with ~75% of projects undertaken in the last 70 years under 3 ha in size (Figure 3.2).

Figure 3.1

Figure 3.2 Projects by Size

Japan and South Korea have restored the most area and have often led the field in past decades. This success has been achieved through a combination of political will, advanced systems for growing kelp, and reliable, long-term project funding and support by the federal government. Elsewhere, kelp restoration work has been largely experimental, supported by limited funding and policy interest¹ and with new methods still under development. These factors have resulted in only small areas being restored in many regions. For example, the United States and Australia have recorded many individual projects (Figure 3.3) over the years but have restored little total area since the 1990s.

Figure 3.3

3.4 Successful Restoration

Restoration is most successful when it is done at ecologically meaningful scales (> 1-10 ha), when in close proximity to an existing kelp forest, when the original reason the kelp disappeared is addressed and removed, and when it provides ecological, social, and economic benefits to communities. Success in kelp restoration is best shown by the projects in Japan and Korea. These projects have been well funded by government-backed programs, and this involvement ensured the resources and stability needed to achieve such success. As a result, the projects have restored kelp forests at large scales and seen meaningful ecological and social benefits such as the revival of fisheries².

To provide the best chance of large-scale restoration success, future projects should learn from past lessons, while governments should model the stable and committed funding models found in Japan and Korea.

South Korea is home to the world’s largest kelp restoration project. Starting in 2009, the federally run Korean Fisheries Resource Agency pledged to restore 54,000 ha of kelp forests by 2030 and has now placed 29,000 ha of area under restoration across the country, with an approximate success rate of 50%. The project initially relied on artificial reefs and transplants, but after facing public opposition to eco engineering, it shifted towards restoring rocky reefs instead of creating new habitat. Restorative techniques leverage the country's aquaculture expertise, including rearing kelp for planting and dispersing zoospores. South Korea has also seen a growing interest in the management of sea urchin populations. The role of these populations in the failure of earlier restoration efforts is being addressed, and this is vital given that urchin barren formation continues to be a prevalent inhibitor of kelp persistence here and globally³.

Japan has trialled many different restoration methods over the years, with hundreds of projects in the last century. While records for many historic projects are difficult to access in English, there is evidence from the Shizuoka prefecture of the world’s largest single restoration project using transplants (870 ha). Japan has now launched J-Blue Credit, the world’s only blue carbon kelp forest credit, so new projects are being accelerated. Since 2022, ~600 ha of kelp forest has been restored under this initiative⁴.

Resources for Guiding Successful Implementation

The Kelp Restoration Guidebook provides the most comprehensive information for effective and ethical kelp forest restoration, starting with project management and continuing all the way through the process to reporting.

An overview of The Korean Fisheries Resources Agency guidelines (translated) is provided here, and an overview of the Japanese kelp restoration lessons is provided here (Japanese).

The Kelp Ecosystem Monitoring Guidelines also provide support for standardised data collection and reporting in kelp forest ecosystems, restored or otherwise. These guidelines will be useful in better quantifying the benefits resulting from kelp restoration.

3.5 Future Restoration

As kelp restoration grows into an established field across the world and our oceans continue to face existential threats, there is a pressing, yet achievable, need to scale up the number and size of restoration projects. Countries such as Australia, the United States, Canada, and Chile have documented significant kelp decline and may now take the opportunity to scale up their existing restoration projects. There are already emerging large-scale restoration projects in Sydney, Tasmania, Northern California, and Southern Chile. Importantly we also need to act by stewarding and restoring before another headline about a 95% kelp forest decline grabs our attention.

A global roadmap for upscaling kelp forest restoration can be found here. However, each country needs to make its own assessment of the amount of area that should be restored, can be restored, and how and where that restoration will take place.

New restoration projects can connect with emerging initiatives such as Nature Based Solutions, the Nature Positive Movement, Natural Capital Account, and, where appropriate, Blue Carbon, such as Japan’s J-Blue Credit.