Received: Aug 12, 2025 / Accepted: Oct 08, 2025 / Published: Dec 31, 2025
Coastal aquaculture zones, including areas for shrimp and mollusk farming, are subject to multiple stressors, such as internal farming activities, inland runoff, and extreme weather events. These factors contribute to spatiotemporal fluctuations in water quality, directly affecting aquaculture productivity and sustainability. This study aimed to assess the current status of the water quality in the shrimp and clam farming areas across the Nam Dinh coastal districts identify the spatial and temporal variation trends, and propose appropriate management measures. Environmental parameters, including pH, dissolved oxygen (DO), salinity, alkalinity, COD, ammonium (N-NH₄⁺), nitrite (N-NO₂⁻), hydrogen sulfide (H₂S), total suspended solids (TSS), and total Vibrio count, were monitored biweekly. The samples were collected on the same day between 5:00 and 7:30 a.m. The results indicated significant temporal fluctuations in water quality, with a clear deterioration trend during the rainy season and in storm-affected months, particularly in September, during the passage of Typhoon Yagi. In the shrimp farming areas, the water source quality tended to decline during June-August. Localized differences were also observed: Nghia Hung was characterized by low DO levels, while Hai Hau experienced large salinity fluctuations. In the clam farming zones, water quality was lowest in June and July. Giao Thuy exhibited a higher frequency of salinity values falling below acceptable thresholds compared to Nghia Hung, suggesting greater variability in salinity levels. These findings provide a scientific basis for local authorities and farmers to plan adaptive water management strategies, such as storing high-quality water for use during periods of environmental stress.
