Growing maricultured corals in Indonesia

Reef education specialists are planting 20,000 corals grown in rope-and-rack nurseries to restore ocean habitats and build on locally led marine innovation.

Image © Ocean Gardener

Image © Ocean Gardener

Key facts

  • Only One members are funding the planting of 20,000 corals in the waters of Nusa Penida, an Indonesian island located in the Coral Triangle, famous for its unparalleled marine biodiversity.

  • The project rebuilds the reef using sustainable techniques, saves critical fish habitat, and is led by local experts on marine conservation and innovation.

  • Our coral planting partner Ocean Gardener was founded in 2016 by reef education specialists with 20 years of hands-on experience working with Indonesian coastal communities.

  • The coral planting site lies within the Nusa Penida marine protected area, which was selected as a Hope Spot by Sylvia Earle’s Mission Blue, and is home to nearly 300 coral species and over 500 reef fish species.

How the project works


Ocean Gardener grows coral fragments using mariculture, i.e., in the natural marine environment.

Ocean Gardener


Long ropes are strung up between at least two large pieces of locally-collected wood, which has special properties that prevent it from rotting underwater.

Ocean Gardener


Coral fragments are spun into the ropes, with trained Ocean Gardener team members assessing the water temperature and conditions to determine the optimal time for planting to ensure the best chance of survival. Each two-meter rope can hold up to ten corals.

Ocean Gardener


Four to five months later, once the corals have attached themselves and started to grow, the ropes are moved using lifting bags and transplanted to the reef slope. The thick rack resists waves and provides a layer of protection for the more delicate corals.

Ocean Gardener


Ocean Gardener’s team tracks ongoing coral growth and health with 3D monitoring at the planting site.

Ocean Gardener

Become a member of Only One today to fund Ocean Gardener’s project and take direct action to save the planet — planting your own ocean forests and coral reefs, and removing plastic and carbon pollution.

Project impact

All projects on Only One help save the ocean and fix the climate, and 100% of our members’ funds go to impact. Keep reading to discover how our “Growing maricultured corals in Indonesia” project is having a positive effect.

Biodiversity and ecosystems

Ocean Gardener carries out their reef restoration in the waters surrounding Nusa Penida, an Indonesian island located in the Coral Triangle. Sometimes called “the Amazon of the ocean,” the Coral Triangle spans 2.3 million square miles (6 million square kilometers) in the Pacific and is, as its name suggests, roughly triangular in shape! What is so impressive is that the Coral Triangle contains 30% of the reefs on our planet, despite covering only around 1% of the ocean floor. There is evidence that the Coral Triangle is more resilient to climate change because of its environmental complexity — so there are likely lessons to be learned for rebuilding the reef elsewhere in the world. The coral planting site supported by Only One members lies specifically within the Nusa Penida marine protected area, which was selected as a Hope Spot by Sylvia Earle’s Mission Blue, and is home to nearly 300 coral species and over 500 reef fish species, of which a few are new to science.

Biletskiy Evgeniy

Wildlife protection

The primary purpose of Ocean Gardener’s project is to restore habitat for reef fishes, like the fairy wrasse (Cirrhilabrus flavidorsalis). This is doubly important because Ocean Gardener works in tandem with fisherfolk to make reef restoration projects happen and help forge sustainable relationships between themselves and their marine environment. Reefs have the most diverse fish assemblages anywhere on Earth, housing as many as 6,000 to 8,000 different species, so conserving Nusa Penida’s coral ecosystems is critical for wildlife.

Daniel Lamborn

Community development

Ocean Gardener works in partnership with Nuansa Pulau, a local coral lover association, to plant corals using sustainable techniques. The coral lovers of Nuansa Pulau have grown up fishing and witnessed the declines in coral cover and fish catches. They are trained coral farmers, familiar with all kinds of mariculture. Nusa Penida islanders have a long tradition of seaweed farming, which involves tying long ropes between pieces of water-resistant wood, and Ocean Gardener’s project builds on these innovative techniques and equipment to regrow corals for planting. Twenty-six members of the local Indonesian community play an active role in the project.

Ocean Gardener

Coral species

The coral species being planted in Nusa Penida, chosen for their unique capacity to complement high-energy reef ecosystems, are:

  • Acropora abrotanoides, a thick, robust branching coral that provides a strong foundation for the reef and will in time protect smaller, more delicate surrounding corals from waves and currents.

  • Acropora cerealis, a short, bushy branching coral that acts as a hiding spot for baby fish, known for its hardiness and vividly-colored tips.

  • Acropora hyacinthus, a coral that forms wide, flat plates with little branches, helping to shade lower parts of the reef.

  • Acropora tenuis, a hardy, fast-growing coral commonly found in the Indo-Pacific that comes in many colors: purple, blue, green, and cream.

  • Hydnophora excess, a coral that is more resistant to parasites and bleaching than the Acropora species, with a unique ability to not only branch but also encrust, adhering to hard rocky surfaces and growing larger in diameter versus upward.

Acropora abrotanoides · Ocean Gardener

Sustainable Development Goals

By supporting the “Growing maricultured corals in Indonesia” project, Only One members’ funds go toward this United Nations Sustainable Development Goal (SDG). 

Project reporting

Ocean Gardener will send Only One a detailed report four months into the project and at the end of 2022. Their team also sends us regular email updates on when corals are being restored and how healthy they look.

Tropical Studio

More about our coral planting partner

Founded in 2016, Ocean Gardener is a nonprofit organization dedicated to reef education and conservation, made up of marine biologists, divers, and coral farmers. More than 20 years ago, their team envisioned and created the first coral mariculture farms in Indonesia, in close collaboration with local coastal communities, with the goal of promoting sustainable livelihoods from the reef. The team at Ocean Gardener are big advocates of proper reef education as a vital tool for protecting our coral ecosystems.

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