Saltwater Lakes in Ha Long Bay

Ha Long Bay is home to many saltwater lakes, also known locally as "Ang." These Ang are karst sinkholes formed through geological tectonic processes and are connected to the sea by narrow openings or underwater caves, causing the water levels in the lakes to rise and fall with the daily tides. These lakes are located among the islands and represent a unique geographical feature specific to the Ha Long Bay area.

The lakes are isolated from the external environment, surrounded by limestone islands that create a tranquil, clean, and cool atmosphere. The shores are covered with lush green vegetation, while underwater lies a vibrant ecosystem of marine life, forming a beautiful and peaceful habitat that is distinct and highly attractive, full of fascinating surprises.

This natural condition has created a biological community in the lake beds that is isolated from the outside. Notable species include coral, pearl oysters, green mussels, sea cucumbers, clams, and Guot seaweed. The surrounding vegetation is also rich and well-developed, dominated by endemic plants of Ha Long Bay such as Five-leaf Aralia, Ha Long Palm, Ha Long Fig, Ha Long An Dien, Ha Long Ginger, and Ha Long Jasmine. Additionally, the area is home to some animal species such as salamanders, monkeys, and birds including the Black Drongo, Crow, and Hawk.

During low tide, some Ang reveal a system of frog-mouth caves connected to the outside. Visitors often explore these by kayaking or riding on bamboo boats to admire the lakes’ natural beauty. Notable Ang include the Maze Ang, Goby Fish Ang, Parachute Ang, the Luon Cave area, Ba Hang area, and the Ba Ham Lake area.

Several saltwater lakes have been studied and show potential for tourism development, including activities such as kayaking, mountain climbing, and cave exploration. Currently, the Ha Long Bay Management Department is collaborating with research institutes to assess the value of these saltwater lakes, conduct biodiversity surveys, and develop management profiles. So far, 81 saltwater lakes have been identified, including those located in both the buffer zones and the core zones of the Ha Long Bay.

The provincial-level scientific project titled "Research on the Values of Underwater Caves and Saltwater Lakes in Ha Long Bay", conducted by the Ha Long Bay Management Department in collaboration with a team of experts from the Institute of Marine Resources and Environment, was successfully completed and approved in October 2017.

The research results provide a scientific basis for the conservation and enhancement of the values of these unique ecosystems. At the same time, the study helps identify and develop unique and responsible tourism products that sustainably exploit the potential of underwater caves and saltwater lakes, contributing to the sustainable tourism development of Ha Long Bay.

It is hoped that in the near future, many saltwater lakes in Ha Long Bay will be developed for tourism purposes, enriching and increasing the attractiveness of Ha Long Bay’s tourism offerings.

Translated by Thuy Ha