The coral reef is often dubbed the “rainforest of the sea”—it serves as the bedrock of ocean life, offering shelter and foraging grounds for thousands of marine species. However, in many areas, including Phu Quoc, coral reefs are facing severe degradation due to climate change, bleaching events, and irresponsible human activities such as exploitation and tourism. Therefore, their restoration and conservation have become more critical than ever.
To proactively address this challenge, OnBird Phu Quoc has collaborated with marine biologists to launch a Coral Nursery Project in the South of the island, starting in May 2025. This article aims to release the findings from the periodic four-month inspection (May – September 2025), which show encouraging positive signs, and to announce the project’s imminent expansion plan.
MAIN CONTENTS
I. Decoding the Technology: A Sustainable, Natural Coral Nursery Model
The coral nursery project, spearheaded by OnBird and marine biologists, is designed to regenerate the stock of critical coral groups that are severely degraded. Once mature, the corals from the nursery will be fragmented and transplanted back into the deteriorated reef areas.
A. Origin and Selection Criteria for Cultured Corals
The coral source for the nursery is selectively and carefully collected from the natural environment. Our team prioritizes the propagation of important reef-builder species that are either broken or under threat in the wild.
To ensure rapid and effective restoration, the selection criteria for cultured corals are stringent. Scientists will prioritize species with high vitality and fast growth rates, such as table corals or staghorn corals, so they can quickly reach the required size for transplanting back into natural reefs.
B. Structure and Cultivation Method
The nursery is established in a meticulously surveyed, secluded underwater area to minimize external impact.
- Platform Design: The nursery structure is a robust combination of submerged rock blocks at the base and a stainless-steel frame, ensuring stability against strong currents.
- Suspension System: A distinctive feature of this model is the use of anchor lines connected to small buoys, forming a roof-like structure. The coral fragments are then tied to these lines. OnBird and the biologists use a micro-fragmentation technique on both the suspended line substrate and a hard substrate on the sandy seabed, at a depth of 3–4m, to optimize coral growth.
- Micro-fragmentation Method: Corals are fragmented from larger colonies to conserve stock and enhance their ability to attach to the substrate and fuse into a reef.
| For you to watch: Coral Nursery Project in Phu Quoc Island, Vietnam
C. Advantages of Natural Development
With the techniques employed in the nursery and the ideal geological location, the corals have the opportunity for holistic development. All surfaces of the coral fragments are freely exposed to surrounding nutrients and light. They develop naturally and vigorously without the need for any catalysts or electrochemical equipment. This method ensures healthy growth and strengthens the corals’ ability to adapt.
II. Inspection Report (September 2025) – Encouraging Positive Results
The recent monitoring inspection, organized by OnBird four months after the project’s official launch in May 2025, has yielded extremely promising data and indications regarding the nursery model’s effectiveness.
A. Survival Rate and Technical Stability
- Positive Survival Rate: The coral survival rate is a highly encouraging 99%. This near-perfect figure indicates the optimal suitability of the water environment and the care techniques employed.
- Adhesion Quality: All corals have securely attached to the substrate, a key factor ensuring their long-term stability and resilience against wave action.
- System Safety: The buoy-suspension system remains secure and operational, keeping the nursery running continuously and effectively.
- Appearance of Drupella Snails: Due to a reduction in the natural predators of Drupella snails, an outbreak of this corallivorous species has been observed in some areas of Phu Quoc. We will need to address this using both physical and biological control methods to protect the corals.
B. Productivity and Coral Stock Potential
Frequent and close monitoring allows OnBird to accurately assess the most suitable coral species. Three coral species are developing exceptionally well and showing good productivity, making them ready to become the primary stock for upcoming large-scale transplantation projects:
- Acropora Grandis
- Porites Cylindrina
- Acropora Rosaria
This high-quality stock confirms the project’s self-sufficiency and its potential for scaling up restoration efforts. Below are some close-up images of the aforementioned coral species:
C. Signs of Ecosystem Revival (Visual Evidence)
The most heartening sign is not only in the corals themselves but in the ecosystem’s revival. After four months, the fish population has visibly increased, a stark contrast to the sparsely populated, degraded reef area prior to the project.
This is a positive indicator of ecosystem recovery. The return of fish, shrimp, and other organisms proves that the coral nursery is becoming a safe refuge, feeding, and breeding ground, confirming that the model has successfully begun to regenerate a diverse marine community.
IV. Accelerating Restoration: 500m² Expansion Plan in October
Given the initial successes achieved, OnBird and partners are accelerating the expansion phase to speed up the recovery of natural coral reefs.
A. Short-Term Plan and Scale of Expansion
- Nursery Expansion: To meet the demand for large-scale transplantation, OnBird will deploy two additional grow-out tables in the nursery, increasing the stock-rearing capacity.
- Major Transplantation Campaign: Early this October, OnBird will launch a campaign to transplant six different coral species across a 500m² area within the Coral Jungle Reef area, aiming to enhance both the scale and the biodiversity of the reef.
B. High Applicability and Long-Term Vision
This nursery model boasts high applicability and is designed for multiple reuses.
Once coral fragments reach the required size, scientists will return to harvest them, detaching them from the nursery structures. They are then transported to damaged coral areas for out-planting, thereby regenerating new, healthier coral populations.
This method offers a long-term, highly effective natural coral conservation solution, establishing a solid foundation for the future resurgence of coral reefs.
V. Collaborating for a Sustainable Blue Ocean
The positive signals from the coral nursery in Southern Phu Quoc—with a 99% coral survival rate, the return of reef fish, and an efficient cultivation model—affirm that the collaborative efforts between OnBird and marine biologists are on the right track. This project is living proof that scientific intervention coupled with dedication can make a significant difference beneath the ocean’s surface.
Coral restoration is a long-term journey that requires the cooperation of the entire community. We encourage you to follow, support, and join OnBird Phu Quoc in our marine conservation efforts, turning every trip into an opportunity to contribute to the future of our oceans.