01 — The basics
Along Australia's southern and eastern coast, towering canopies of giant kelp once swayed in cool, nutrient-rich water. In many places they are now gone. Kelp forest restoration is the work of bringing those forests back — and Australia has become one of the most important places in the world to get it right.
What kelp forest restoration means
Restoring kelp forests means re-establishing healthy stands of kelp on reefs where the forest has thinned or vanished. That can involve protecting the forest that remains, easing the pressures that wiped kelp out in the first place, and physically returning young kelp to the reef so it can grow, reproduce, and spread on its own. Done well, it is less about planting a garden and more about restarting an ecosystem.
Why Australia is a focus for kelp restoration
Australia's temperate reefs form the Great Southern Reef, a connected system of rocky reefs and kelp forests that runs along the southern coastline. It underpins valuable abalone and rock-lobster fisheries and shelters a remarkable range of marine life, much of it found nowhere else.
This system has suffered serious losses. Off eastern Tasmania, giant kelp forests have declined dramatically — a decline of around 95% is widely reported — driven by warming water and a strengthening East Australian Current. The loss was severe enough that Australia's giant kelp marine forests were listed as a threatened (endangered) ecological community under national environmental law. That listing made restoring kelp a recognised priority, not just a nice idea. It also makes kelp central to the broader effort of rewilding Australia's coasts.
- Great Southern Reef
- Australia's connected temperate reef system, where most kelp restoration here is focused.
- ~95% decline
- The widely reported loss of giant kelp forests off eastern Tasmania.
- Listed as threatened
- Giant kelp marine forests are a protected endangered ecological community under Australian law.
The main approaches to restoring kelp
There is no single way to restore a kelp forest. In practice, restoration draws on a mix of methods, often used together:
- Protecting remaining forest: the cheapest restoration is preventing loss. Safeguarding healthy stands keeps a source of spores nearby for natural recovery.
- Controlling sea urchins: where reefs have become urchin barrens, reducing urchin density gives kelp a chance to re-establish instead of being grazed away.
- Green gravel and seeding: young kelp is grown on small stones or other surfaces in a hatchery, then scattered onto the reef, where the kelp attaches and grows. It is a simple, low-cost way to spread seeded kelp over an area.
- Active replanting and seaweed farming: kelp can be grown on engineered lines and structures, much like seaweed farming, then established near degraded reef to help a forest return.
Why restoration is hard
The hopeful news is that kelp can come back. The hard news is the scale. The reefs involved stretch for hundreds of kilometres, the underwater work is slow and costly, and conditions keep shifting as the ocean warms. Most restoration projects also share one weakness: they run on grants. When the grant ends, the work stops — often before a forest is self-sustaining.
That funding cliff is the problem Ocean Greens is built to solve. By harvesting a sustainable share of farmed kelp and selling it, the aim is to generate revenue that pays for restoring the next stretch of reef — so the work can keep going after any single grant runs out.
How Ocean Greens restores kelp
Ocean Greens follows a four-step method. We describe the outcomes below as our goals and targets, not as results already achieved.
- Remove: clear sea urchins from a stretch of degraded reef so kelp is no longer grazed out the moment it appears.
- Seed: place native kelp on engineered lines, using local species suited to the reef.
- Grow: kelp is among the fastest-growing organisms on Earth, so a seeded farm can build a dense canopy in a single season.
- Rewild: the goal is for mature farms to release spores that re-seed the surrounding reef, helping a wild forest re-establish beyond the farm itself.
Common questions
What is kelp forest restoration?
It is the work of bringing kelp back on reefs where it has been lost — by protecting remaining forest, reducing urchin grazing, seeding young kelp, and actively replanting native kelp so a forest can re-establish.
Why is Australia a focus for kelp restoration?
Australia's temperate reefs form the Great Southern Reef. Giant kelp off eastern Tasmania has declined heavily — around 95% is widely reported — and is listed as a threatened ecological community under national law, making restoration a priority.
How do you restore a kelp forest?
Through a mix of protecting healthy forest, controlling sea urchins, seeding methods like green gravel, and active replanting or seaweed farming. Ocean Greens removes urchins, seeds native kelp on engineered lines, grows it, and aims for mature farms to re-seed the reef.
Why is kelp restoration hard to scale?
It is costly, the reefs are large, and most projects depend on grants that eventually run out. Ocean Greens is building a self-funding model so harvesting farmed seaweed can help pay for the next stretch of reef.