Guangxi Key Laboratory of Marine Environmental Change and Disaster in Beibu Gulf, Beibu Gulf University, Qinzhou 535011, China.
Shenzhen Marine Environment Monitoring Center, State Oceanic Administration of China, Shenzhen 518067, China.
Mar Pollut Bull. 2024 Sep;206:116689. doi: 10.1016/j.marpolbul.2024.116689. Epub 2024 Jul 14.
Seawater physicochemical parameters and environmental capacity are important ecological indicators and typical features of the marine environment. It has great significance in the marine material cycle and ecological health. In September 2021 (wet season) and March 2022 (dry season), two voyage investigations were conducted at 12 stations (D1-D12) on Dapeng Bay (DPB), northern South China Sea. The distribution of nutrient, water-quality status, environmental capacity, and impact of ecological environment were discussed. Results showed that NH-N was the main form of dissolved inorganic nitrogen (DIN) during the wet season, with concentrations ranging from 0.008 mg/L to 0.109 mg/L, accounting for ~53 % of DIN. Conversely, NO-N was the main form of DIN during the dry season, with concentrations ranging from 0.005 mg/L to 0.117 mg/L, accounting for ~50 % of DIN. The DIP concentration ranged from 0.002 mg/L to 0.019 mg/L, accounting for ~51 % and 31 % of the total dissolved phosphorus in the wet and dry seasons, respectively. The distributions of NH-N, NO-N, NO-N, and DIP were relatively similar, decreasing from the inner bay to the outer bay. The eutrophication indices of 12 stations <1, indicating a poor eutrophication state. Single-factor indices including chemical oxygen demand (COD), DIN, and dissolved inorganic phosphorus (DIP) were less than the class I seawater-quality standard. However, except for station D1, the overall water quality was good. Dissolved oxygen with DIP had a significantly negative correlation during the dry season, indicating that DIP was primarily dominated by marine biological activity and organic-matter decomposition. The remaining environmental capacities of COD, DIN, and DIP in DPB were calculated to be 13,742, 1418, and 141 tons, respectively. Based on the functional-zone division of the sea area, the remaining environmental capacities of COD, DIN, and DIP were exceeded 75 % of the total environmental capacity. This study provided a scientific basis for the protection of marine ecological environment and the sustainable development of DPB.
海水理化参数和环境容量是海洋环境的重要生态指标和典型特征。它们在海洋物质循环和生态健康中具有重要意义。2021 年 9 月（湿季）和 2022 年 3 月（干季），在南海北部大鹏湾（DPB）的 12 个站位（D1-D12）进行了两次航行调查。讨论了营养物质的分布、水质状况、环境容量以及生态环境的影响。结果表明，在湿季，NH-N 是溶解无机氮（DIN）的主要形式，浓度范围为 0.008-0.109mg/L，占 DIN 的53%。相反，在干季，NO-N 是 DIN 的主要形式，浓度范围为 0.005-0.117mg/L，占 DIN 的50%。DIP 浓度范围为 0.002-0.019mg/L，分别占湿季和干季总溶解磷的51%和31%。NH-N、NO-N、NO-N 和 DIP 的分布较为相似，从内湾到外湾逐渐减少。12 个站位的富营养化指数均<1，表明富营养化状态较差。包括化学需氧量（COD）、DIN 和溶解无机磷（DIP）在内的单因子指数均低于一类海水水质标准。然而，除了站位 D1 之外，整体水质良好。干季时，DIP 与溶解氧呈显著负相关，表明 DIP 主要受海洋生物活动和有机物质分解的影响。大鹏湾的 COD、DIN 和 DIP 的剩余环境容量分别计算为 13742、1418 和 141 吨。基于该海域的功能区划分，COD、DIN 和 DIP 的剩余环境容量分别超过了总环境容量的 75%。本研究为大鹏湾海洋生态环境的保护和可持续发展提供了科学依据。
