Spatial Distribution of Marine Aquaculture and Estimation of Aquaculture Pollution Load in Xincun Lagoon, Hainan, China

The spatial distribution pattern of marine aquaculture in Xincun Lagoon, Hainan, China, and the resulting pollution have a significant impact on the surrounding water ecological environment. This study focuses on mariculture (specifically fish farming) in the area and examines its spatial distribution pattern and pollution load. Based on the pollution coefficients of the main cultured species, combined with the culture area and average yield, the pollution load of the cultured species can be estimated. The findings reveal that fish farming in Xincun Lagoon generally exhibits a ‘Y’-shaped distribution, with the culture areas concentrated near the entrance gate and adjacent sea areas with favorable hydrodynamic conditions. The A10 breeding block has the highest proportion of breeding areas, particularly for grouper breeding, which accounts for 45.01% of the total breeding sea area. The pollution loads generated by various cultured species include 170,965.91 kg of total nitrogen, 28,579.64 kg of total phosphorus, 345,047.18 kg of COD, 2.78 kg of heavy metal copper, and 91.60 kg of zinc. The A10 breeding block also has the highest pollution production. The issue of excessive breeding pollution load is closely linked to the spatial distribution pattern of breeding. Therefore, relevant management departments should implement measures to allocate and plan breeding density and distribution in a manner that ensures a healthy water breeding environment.