The Nha Trang Institute of Oceanography has recently discovered the presence of single-leaf seagrass (Halophila decipiens) at depths exceeding 6 meters in the waters surrounding the Hai Tac archipelago, located in Kien Luong District, Kien Giang Province.
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Single-leaf seagrass (Halophila decipiens) |
Although the distribution area of this seagrass is not large, it contributes to demonstrating the richness of seagrass species in Vietnam.
This also serves as a basis for explaining why the Dugong (Dugong dugon) frequently appears in these waters.
According to scientists, the waters of Kien Giang host up to 10 species of seagrass, attracting many rare and endangered marine animals.
Local residents have reported that for the past three years, a group of approximately 10 Dugongs has been sighted in the waters of the Hai Tac archipelago.
Previously, a study by Assoc. Prof. Dr. Nguyen Van Tien, from the Institute of Oceanography in Hai Phong, indicated that the overall area of seagrass beds in Vietnam has decreased by 40-60%.
Currently, according to preliminary statistics, the area of seagrass distribution in Vietnam is estimated to be over 10,000 hectares.
In our country, seagrass typically grows in coastal intertidal areas, around islands, river mouths, mangrove forests, lagoons, pools, and bays.
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A seagrass bed of single-leaf seagrass |
Seagrass species grow almost year-round, with optimal growth occurring in spring and early summer, and reduced growth during the rainy season. They are found from intertidal zones to depths of 3-15 meters, and even up to 28 meters (Bach Long Vi Island). They thrive in salinity levels of 0.5-3.4%, with substrates composed of fine silt, sandy mud, coral sand, coarse sand, or gravel.
Seagrass beds help stabilize and protect the seabed through their root systems, creeping stems, and fallen leaves. They play a crucial role in preventing or minimizing coastal erosion and damage.
The role of seagrass in nutrient cycling in the world’s oceans is estimated to be worth $3.8 trillion, with the economic value of 1 hectare of seagrass reaching up to $212,000 per year.
In Vietnam, initial research results indicate that the economic value, including both extractive (seagrass and associated species) and non-extractive (environmental ecology) benefits of seagrass, is relatively high (for example, Cam Ranh Bay: $7,920,000; Tam Giang-Cau Hai Lagoon: $1,628,000; Bai Bon in Phu Quoc Island: $481,202).
