Coral Planting: How Reef Restoration Actually Works

Six stages, in order. The glamorous bit is stage four and it is the one that matters least.

1. 01

   Choose a site that can actually hold coral

   Site selection decides most of the outcome before anyone gets in the water. Teams survey depth, current, sediment load, remaining live coral cover and the condition of the substrate. Reefs that are still being blast-fished, buried in sediment or stripped of grazing fish will not keep planted coral alive, however good the planting is.

2. 02

   Source the fragments

   There are three routes. Rescue fragments that storms and anchors have already knocked loose, which is what the Nusa Penida project does. Cut small pieces from resilient wild colonies and grow them in a nursery for roughly a year, which is Coral Gardeners' method. Or micro-fragment a single colony into many pieces that later fuse back together. Only the first two are common.

3. 03

   Prepare the surface

   Coral needs hard, still ground. On dead but intact reef that means scraping algae and sediment off a patch of rock. On a rubble field it means stabilising the rubble first with mesh, cement, rock piles or modular steel structures, because loose rubble grinds settling larvae to death every time the current turns.

4. 04

   Attach the coral

   Fragments are fixed with marine epoxy, cement, nails and wire, cable ties or purpose-made plugs. The attachment has to hold for the months it takes the coral to cement its own skeleton to the substrate. Materials matter more than they sound: the Nusa Penida team trialled zip ties, hemp rope, cotton twine, stainless steel and aluminium wire, and switched to aluminium after the trial.

5. 05

   Come back, repeatedly

   Planted coral is tended, not installed. Dive teams return to brush off macro-algae, remove coral-eating Drupella snails and encroaching sponges, re-secure fragments that have worked loose, and replace losses. A project without a maintenance schedule is a set of structures on a seabed.

6. 06

   Measure what happened

   Credible projects publish method and outcome: fragment-level survival logs, photo transects on fixed quadrats, fish counts, benthic diversity surveys, and increasingly 3D photogrammetry so a patch can be compared year to year rather than remembered. The number that matters most is natural recruitment, baby corals nobody planted settling by themselves.

The answer depends almost entirely on the coral's shape. NOAA's National Ocean Service puts branching corals at 10 cm or more of linear growth a year and massive, boulder-forming corals at 0.3 to 2 cm. That is a thirty-fold difference, and it is the single most useful fact in this whole article.

A coral reaching hand size is not the same as a reef recovering. Reef recovery is measured as a carbonate budget: whether the structure is accreting limestone faster than erosion and grazing remove it. On that measure there is now at least one encouraging published result. Lange and colleagues reported in Current Biology in 2024 that at the restored Pulau Bontosua site in South Sulawesi, Indonesia, carbonate budgets had recovered to levels comparable with healthy reference reefs within four years of planting.

Four years is fast, and that site had unusually favourable conditions and a well-funded method behind it. Treat it as an upper bound of what good restoration can do, not a typical timeline.

A short, honest list. Two of these are our own partners and are marked as such; the rest are included because they are the organisations whose published method and results are worth reading, not because they are connected to us.

Most businesses that want to back reef restoration run into the same wall: the projects worth funding are small field teams, and sponsoring one means a deck, a contract and a minimum commitment. 1ClickImpact exists to remove that step. Coral is a first-class impact type, billed per fragment, with no platform fee and no minimum.

15 coral fragments · $33

$2.20 each, transplanted by hand across a mix of species

1 reef structure

about 2,160 cm² (335 in²) of reef, holding rubble down for good

The fragment is the billable unit because it is the smallest thing a diver physically attaches. One fragment covers roughly 144 cm² of reef as it grows. If you want to adopt a coral reef rather than fund individual fragments, 15 fragments is one whole structure, and the same purchase can be sent to someone else as a gift.

Restore 5 coral fragmentsGift coral restoration

curl --location 'https://api.1clickimpact.com/v1/restore_coral' \
--header 'Content-Type: application/json' \
--header 'x-api-key: YOUR_API_KEY' \
--data '{
    "amount": 15,
    "customer_email": "maya@example.com",
    "customer_name": "Maya"
}'

That request funds fifteen fragments, one full reef structure, and credits it to Maya. She gets her own certificate and a live tracking page. Drop customer_email if the impact belongs to your company rather than a customer.