Impact of Shrimp Farm Effluent on Water Quality in Coastal Areas of the World Heritage-Listed Ha Long Bay

Shrimp farming in the UNESCO World Heritage-listed Ha Long Bay significantly degrades water quality, with effluent containing high levels of nutrient waste causing eutrophication. Research found that concentrations of Total Ammonia Nitrogen (TAN), Nitrite-Nitrogen (NO2-N), Nitrate-Nitrogen (NO3-N), Total Phosphorus (TP), Dissolved Orthophosphate (PO4-P), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Chlorophyll-a (Chl-a) were markedly higher in tidal creeks directly receiving shrimp farm effluent compared to adjacent areas. These levels exceeded recommended thresholds for aquatic ecosystem protection, particularly after the main shrimp crop season. The study employed spatial and temporal sampling across three locations—inside effluent-receiving creeks, outside concentrated farms, and distant from farms—to assess water quality parameters using standard methods. Principal Component Analysis (PCA) revealed distinct patterns of nutrient co-variation, underscoring the urgent need for stricter environmental regulations to sustain Ha Long Bay's marine ecosystem.

Ziad. (2012). Impact of Shrimp Farm Effluent on Water Quality in Coastal Areas of the World Heritage-Listed Ha Long Bay. American Journal of Environmental Sciences, 8(2), 104–116. https://doi.org/10.3844/ajessp.2012.104.116