Local residents said the mangroves, planted in 1994, serve as a natural barrier reducing wave impact and protecting sea dykes and nearby communities from storm surges. The widespread die off is now seriously weakening this protective system.
Thanh, 52, from Hai Ninh Ward, said the forest not only shields the coast but also provides habitat for shrimp, crabs and fish. “As mangrove trees die off, aquatic resources decline and the livelihoods of coastal residents like us are affected,” she said.
Pham Danh Hiep, vice chairman of Hai Ninh Ward People’s Committee, said the die off began in November 2025 after prolonged heavy rainfall caused flooding lasting 26 to 30 days under the impact of storms. Local authorities have reported the situation to higher levels and requested specialised agencies to assess conditions and propose suitable replacement tree species.
According to the Ha Tinh Department of Agriculture and Environment, recent inspections included sampling to check for pests, diseases and water quality indicators.
The majority of dead trees are Avicennia marina, while the other species remained green and continued to grow normally.
The total affected area is about five hectares, including roughly five hectares where trees have died completely, showing dry branches and rotting roots. The remaining two hectares display yellowing leaves, wilting and gradual dieback from the canopy.
Field inspections found no signs of pests or harmful organisms. Cross sections of tree trunks remained fresh, with bright wood and no unusual characteristics. No sources of pollution were identified in surrounding areas.
Water analysis results indicated that all environmental parameters were within permissible limits and met current standards. Soil conditions, climate and salinity levels were also deemed suitable for plant growth.
The department said preliminary findings suggest the cause is not linked to water pollution or biological agents, but the exact factor behind the die off has yet to be determined.
Authorities have urged Hai Ninh Ward to preserve the affected area, monitor developments closely and report updates promptly. The locality has also been asked to review documentation and compile detailed site records to support proposed response measures.
The department further recommended inviting scientists and mangrove experts to conduct surveys and assessments to clarify the cause and identify appropriate solutions.