ONBIRD- DEVELOPED BIOROCK - An Effective And Natural Solution For Coral Reef Restoration In Phu Quoc - OnBird

MAIN CONTENTS

1. Introduction by OnBird Phu Quoc
2. What is Bio-Rock?
3. Descriptions of the Biorocks Developed By OnBird.
The Quantity Of Bio-rocks Placed In The Coral Reefs By OnBird Team

1. Introduction by OnBird Phu Quoc

OnBird Phu Quoc is actively engaged in a project aimed at revitalizing the deteriorated coral colonies in Phu Quoc Island. As part of this initiative, OnBird has been pioneering the development of a novel cement-based bio-rock and natural rock substrate. These bio-rocks serve as ideal substrates for coral larvae attachment and facilitate the transplantation of new coral colonies. A preliminary trial involving the placement of these bio-rocks at selective coral reefs in Phu Quoc has recently been conducted to assess their efficacy.

It is a well-established fact that numerous coral reefs in Phu Quoc remain among the healthiest coral colonies in Vietnam, surpassing those in Nha Trang, Ninh Thuan, and Con Dao, among others. Despite their previous reputation as top-ranking coral reefs in Southeast Asia, some of Phu Quoc’s coral reefs are currently under severe threat. These threats include irresponsible anchoring by local boat tours, overfishing with rake nets, chemical fishing, and the impact of rising water temperatures.

2. What is Bio-Rock?

Biorock (also seacrete) is a cement-like engineering material formed when a small electric current is passed between underwater metal electrodes placed in seawater causing dissolved minerals to accrete onto the cathode to form a thick layer of limestone. This ‘accretion process’ can be used to create building materials or to create artificial ‘electrified reefs’ for the benefit of corals and other sea life. Discovered by Wolf Hilbertz in 1976, bio-rock was protected by patents and a trademark which have now expired.

Coral Jungle Reef, the heathiest coral reef in Phu Quoc Island, Vietnam — Healthy corals in the Coral Jungle Reef, the healthiest coral reef in Phu Quoc Island, Vietnam

Hard corals are pivotal in reef formation as they disperse coral larvae into the water. These larvae drift with the current until they settle in a suitable location, where they develop into mature corals due to a symbiotic relationship with zooxanthellae algae. This partnership is vital as the algae supply approximately 90% of the essential nutrients required by the corals.

3. Descriptions of the Biorocks Developed By OnBird.

Onbird deploy biorocks at some coral reefs in Phu Quoc Island, Vietnam — Onbird places biorocks in coral reefs in Phu Quoc Island, Vietnam

We are in the process of creating biorocks made of cement or from natural rock, featuring strategically placed holes to secure the corals. An intricate aspect of constructing these bio-rocks involves affixing new corals onto them. Typically, divers utilize adhesive to attach fresh corals onto structures above the water, allowing time for the corals to firmly adhere before submerging them into the water.

To address the challenges encountered, we have implemented a strategy of pre-drilling small holes in the rock to secure new corals instead of relying on adhesive.

Following the initial Biorock setup, the cauliflower corals attached were displaced by fish. As a result, in September, we affixed a broken Cactus Coral to the rock. The outcome of this endeavor can be observed in the following link:

After six months, the coral has significantly expanded in size and firmly established itself on the rock, a development that brings us great satisfaction. Onbird is currently engaged in manufacturing additional bio-rock structures using natural materials, specifically cubic units measuring 10cm x 10cm, as a sustainable alternative to cement-based rocks used during previous testing.