Seawater from the Gulf of Tonkin is good for salt making. The main crops there are rice, sweet potato, peanut, taro and millet, and sub-tropical fruits like papaya, banana, and longan are also plentiful. The large tracts of mangroves growing in marshy land along the coast are a rich source of tannin, an essential raw material for the tanning industry.
Seawater from the Gulf of Tonkin is conducive to salt production. The region's main agricultural products include rice, sweet potatoes, peanuts, taro, and millet, as well as tropical fruits like papaya, banana, and longan. Additionally, the coastal mangrove forests are a significant source of tannin, which is essential for the leather industry.