Nha Trang Bay, March 4, 2025 – The Europe Today: In a groundbreaking development for marine conservation, a research team from the Vietnam-Russia Tropical Centre has successfully collected coral gametes from the wild in Nha Trang Bay, marking the first instance of such an achievement in Vietnam.
This milestone represents a significant leap in the study of coral reproduction and highlights the persistent efforts of scientists working to restore the country’s declining coral reefs.
Advancing Coral Restoration Efforts
Traditionally, Vietnam has relied on asexual reproduction, or coral fragmentation, to propagate corals. This method involves extracting branches from parent coral colonies and transplanting them onto degraded reef areas to enhance coverage. While this technique has proven effective in increasing coral coverage by three to six times within a short period, it lacks long-term sustainability.
Marine ecology expert Võ Sỹ Tuấn noted the limitations of asexual reproduction, explaining, “Not all coral colonies can be fragmented. We can only select certain types suited for this method.” Furthermore, this method does not promote genetic diversity, making reefs more vulnerable to environmental stressors such as rising sea temperatures.
The Potential of Sexual Reproduction
In contrast, sexual reproduction, in which sperm and eggs from different coral colonies combine to produce genetically diverse offspring, offers a more resilient restoration solution. This method has been successfully implemented in Australia, Germany, Japan, and China and is now gaining attention in Vietnam.
Coral spawning occurs through the synchronized release of eggs and sperm into the water, usually triggered by water temperature and lunar cycles. However, the timing of this event remains unpredictable, making its documentation and study highly challenging.
Researcher Đặng Đỗ Hùng Việt explained the complexity of this process, stating, “If the release is not simultaneous, fertilization chances drop sharply as currents sweep gametes away. Corals have evolved to maximize fertilization through mass spawning.”
Capturing a Rare Phenomenon
Given that coral spawning happens only once per year for each colony and lasts mere minutes, the research team conducted hundreds of night dives to capture the fleeting event. Facing strong currents and unpredictable conditions, researchers spent hours underwater in anticipation of the momentous occasion.
“At night, with low tides, we cannot use boats. We swim long distances to reach the corals, facing unpredictable currents that make it dangerous,” Việt shared.
Their dedication was rewarded on April 30, 2024, when they successfully documented coral spawning in Nha Trang Bay—Vietnam’s first recorded instance of this natural phenomenon. The team meticulously collected gametes, which were later separated and cross-fertilized in laboratory settings to ensure genetic diversity and viability for future restoration projects.
A Step Toward Large-Scale Reef Restoration
Nguyễn Như Hưng, coastal branch director at the Vietnam-Russia Tropical Centre, emphasized the broader goal of their research. “We want people to recognize the value of reef restoration and the effort it demands, fostering greater awareness and marine conservation.”
With the initial gamete samples secured, the research team now aims to refine breeding techniques to supply coral stock for large-scale restoration initiatives. Their work is expected to contribute significantly to the preservation of Vietnam’s marine ecosystems amid the growing threats of climate change.
Reflecting on the project, Việt underscored the urgency of their mission: “If corals vanish, the ocean floor becomes barren, and all marine life disappears. That’s what drives me to protect these reefs.”
This pioneering achievement represents a crucial step toward the sustainable restoration of Vietnam’s coral reefs, offering hope for the future of marine biodiversity in the region.
