Great African Seaforest — only floating bamboo kelp forest on the planet

As the battle to arrest the decline in our natural habitat continues, identifying ecological zones that can assist us in this endeavour is critical to our success in achieving our goals. A good example is the Great African Seaforest, a kelp forest that fringes the shores of Cape Town and stretches north for more than 1,000km into Namibia.

Found on a third of the world’s coastlines, which is comparable to land cover by terrestrial forests, kelp forests are as rich as terrestrial rainforests. This equivalence was recognised as early as 1834 by Charles Darwin. In The Voyage of the Beagle, he observed: “I can only compare these great aquatic forests with the terrestrial ones in the inter-tropical region. Yet if in any country a forest was destroyed, I do not believe nearly so many species of animals would perish as would here, from the destruction of the kelp.”

From the shore, kelp often looks like nothing more than brown seaweed bobbing and flowing in the swell. Yet it is more than that: it’s a biodiversity engine that serves as a nursery, shelter and breeding ground for countless marine species and supports an incredible range of life, from tiny amphipods and crustaceans to octopuses and larger animals.

The Great African Seaforest is the only floating bamboo kelp forest in the world and is home to many species that are found nowhere else on the planet.

Sea bamboo (Ecklonia maxima) is the giant of the region, growing as tall as the water is deep – anywhere from 50 centimetres to 15 metres. Even the kelp that washes ashore plays a vital role: it sustains beach-hoppers, kelp flies and isopods, ensuring that life continues seamlessly from ocean to land.

Crucial ecosystems on Earth

Today, kelp forests are some of the most important ecosystems on Earth and are among the prolific primary producers and foundation species on the planet, supporting productivity per unit area that resembles that of tropical rainforests. They deliver services that are not only crucial in the shallow sub-tidal area, but also the adjacent shore and beach ecosystems as well as the deeper seas. Kelp forests are deeply integrated into all ecosystems — marine, terrestrial and atmospheric.

Together with their associated seaweed species, they play a major role in the production of the planet’s oxygen, offer significant global carbon sequestration and extract important levels of nitrogen from the oceans.

Aside from their critical importance in ensuring biodiversity, mitigating climate change, supporting local communities, acting as breeding grounds for fish stocks and delivering ecosystem and planetary health, their economic value add is immense. The United Nations Environment Programme estimated this value at adding more than $500-billion to the global economy each year. These nature-based services from kelp forests play a critical role across multiple dimensions that include people, ecosystems and the economy.

However, kelp forests face serious threats from climate change, overfishing, habitat destruction, acidification, extraction and pollution. Protecting and restoring these underwater forests is not only an environmental imperative but also a necessity for the well-being of communities and the planet.

No protection

Despite their ecological and biodiversity significance, less than 2% of kelp forests globally have any kind of meaningful protection. Because of this, and together with warming waters and ecosystem imbalances due to human impact, more than 50% have vanished or declined in recent times.

It is for this reason that Sea Change believes in the long-term protection of kelp forests, greater awareness and support for science and policy around seaforests.

By protecting and restoring the kelp forests of the world, we can have an impact on mitigating climate change while at the same time catalysing multi-lateral co-operation through the United Nations development goals (SDGs), with the main focus on SDG14. SDG14 focuses on Life Below Water, providing a policy framework critical to the survival and protection of the immediate zones where kelp forests are found.

So much to discover

Four years ago, Sea Change Project launched the 1001 Seaforest Species project, in partnership with the Save Our Seas Foundation, taking a deep dive into the biodiversity of the Great African Seaforest. As we uncover the lives of species thriving in this vast, three-dimensional ecosystem, one truth becomes undeniable: this seaforest is not only uniquely diverse but there is still so much to discover.

That relative intactness of the Great African Seaforest is a rare gift and a national asset we cannot afford to squander. Diving in the kelp forests is an extraordinary visual and sensory experience revealing a wonder world of marine species ranging from octopuses to larger animals.

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Sea Change is also exploring the rich cultural heritage linked to these magnificent underwater forests and the stories they carry about the presence of the early people who inhabited our coastline. Through underwater and shoreline tracking and analysing shell middens, we have been able to unearth a wealth of information and knowledge we can use to better understand the linkages between these kelp forests and those who lived next to them more than 100,000 years ago. Much of this knowledge is now showcased in the Origins of Early Southern Sapiens Behaviour exhibition at Cape Point Nature Reserve.

South African National Parks (SANParks) has started the development of a management plan for the marine protected area (MPA) in Table Mountain National Park – the home of large parts of the Great African Seaforest. The MPA was gazetted in 2014 under the National Environmental Management: Protected Areas Act. This spatial planning is also supported by a range of global multi-lateral treaties.

As part of our ongoing work on the policy front, Sea Change, together with IPOS (International Platform for Ocean Sustainability) introduced the importance of kelp forests at the G20 meeting in Brazil in 2024. Importantly, these recommendations encourage “G20 leaders to drive global policy initiatives recognising kelp forests as critical ecosystems”.

These policy initiatives are important because they form the foundation for deliberate action that can be taken by our Forestry, Fisheries and the Environment minister and his department, SANParks and many non-government organisations.

This would include preservation and enforcement measures aimed at ensuring the long-term viability of our Great African Seaforest and adopting this ecosystem as a valuable national asset that adds value across numerous dimensions, including the enhancement of our overall attempts to bolster our biodiversity initiatives and scientific research, tourism, and cultural heritage, and ensuring these ecosystems retain their roles as nurseries providing fish stock that supplies our fishing industry.

The South African government has also signed a range of international protocols and treaties that are aimed at inner coastal zone sustainability. There exists, therefore, a highly targeted international and national policy framework, which can be leveraged to drive the preservation of our kelp forests.

Ensuring the long term viability of the Great African Seaforest is not only an environmental imperative but also a social and economic investment in South Africa’s future. DM