渤海与主要国际海湾水环境污染治理成效比较研究

自20世纪70年代开始，美国切萨皮克湾、欧洲波罗的海、日本濑户内海及东京湾开展了海洋环境污染治理，采取了一系列减少氮和磷向海洋输入的行动。经过30余年，上述海域总氮和总磷输入量明显减少，尤其是东京湾的总磷输入量减少70%以上。但是海水水质改善程度远低于减排幅度，切萨皮克湾水质达标率增幅仅为15%左右，日本濑户内海和东京湾的总氮、总磷浓度降幅仅为30%左右，波罗的海总体治理效果更差，水体中总氮和总磷的浓度未见明显减少。相比之下，我国渤海海域直排海污染源中氨氮、总氮及总磷入海量削减十分显著，尤其是“十三五”以来，削减幅度均在50%以上，其中氨氮削减超过90%，四类和劣四类海水水质面积在2012年达到峰值后持续降低，降幅近90%。可见，渤海氮、磷削减幅度和水质改善程度均远超上述几个国际主要半封闭海域，渤海综合治理攻坚战成效显著。

Comparative study on the effectiveness of water environmental pollution control between Bohai Sea and major international bays

Since the 1970s, Chesapeake Bay, Baltic Sea, Seto Inland Sea and Tokyo Bay have carried out marine environmental pollution control, and taken a series of actions to reduce the import of nitrogen and phosphorus into the ocean. After more than 30 years, the total nitrogen and total phosphorus inputs in the above-mentioned sea areas decreased significantly, especially the total phosphorus input of Tokyo Bay decreased by more than 70%. However, the improvement of seawater quality is far less than the reduction of emission. The increase of water quality standards attainment in Chesapeake Bay was only about 15%. The decreases of total nitrogen and total phosphorus concentrations in Seto Inland Sea and Tokyo Bay were only about 30%. The overall treatment effect of Baltic Sea was even worse, and the concentrations of total nitrogen and total phosphorus in the water body have not decreased significantly. In comparison, the reductions of ammonia nitrogen, total nitrogen and total phosphorus in the direct discharge sources of Bohai Sea were enormous, especially since the 13th Five-Year Plan, the reduction rate has been more than 50%, of which ammonia nitrogen has been reduced by more than 90%. The areas with water quality worse than Seawater Quality Standard Grade Ⅲ and Grade Ⅳ have continued to decrease after reaching the peak in 2012, with a decrease rate of nearly 90%. It can be seen that the reduction of nitrogen and phosphorus and the improvement of water quality in Bohai Sea were far higher than those in the above mentioned major international semi-closed sea areas, and the battle of comprehensive management of Bohai Sea has achieved remarkable results.