黄海麻坑群沉积物磷的保存与转化及环境效应

基于对北黄海典型麻坑群海域某单位麻坑内部和外缘沉积物中不同赋存形态的磷、甲烷（CH₄）和硫化物等参数的分析，探讨了麻坑独特的环境中磷的转化与埋藏机制、沉积物-水体系磷的释放及对区域磷循环的影响.研究表明，沉积物中碎屑态磷（Det-P）是磷主要的赋存形态（>50%），其次是有机磷（Org-P）、铁结合态磷（Fe-P）和自生态磷（Auth-P），交换态磷（Exch-P）对总磷的贡献较小；麻坑内部与麻坑外缘处沉积物中溶解态活性磷（DRP）向水体的释放通量分别为2.84μmol/（cm²·a）和1.03μmol/（cm²·a），对上层水体的贡献依次为19.6%和3.03%，是上层水体磷的重要来源.麻坑内外磷的埋藏速率与转化过程存在不同；研究区地下水的渗漏是磷的沉积速率和释放通量都普遍高的原因.北黄海麻坑区沉积物中磷的保存与转化还与浅层CH₄的逸出相关，潜在提高黄铁矿的生成速率.较高的沉积物-水界面磷通量必然对区域富营养化等生态环境问题产生深远影响，值得关注.

The preservation and transformation of phosphorus in the pockmark sediments of the Yellow Sea and its environmental effect

In this paper, determinations of phosphorus forms, methane and sulfate and so on were implemented in the typical pockmark area of north Yellow Sea to explore the controlling mechanism of phosphorus transformation and burial under this unique environment and its effect of phosphorus release from sediment-water system on regional phosphorus cycle. The results showed that Det-P(>50%) was the dominant P form in the sediments, followed by Org-P, Fe-P and Auth-P. Exch-P was the minor phase of Tot-P. The diffusive fluxes of dissolved reactive phosphorus (DRP) at B9 and B11 stations were 2.84μmol/(cm²·a) and 1.03μmol/(cm²·a), and their contributions to surface water P loadings were 19.6% and 3.03%, respectively. Observed burial and transformation of phosphorus in and out the pockmark were different; the leakage of groundwater in the study area was the reason for both the high deposition rate and release flux of phosphorus. The preservation of phosphorus in the sediments of the pockmark area in the north Yellow Sea was also related to the escape of shallow methane, which could possibly enhance the formation of pyrite in cores. The higher DRP flux in the sediment-water interface would yield some ecological environment problems like regional eutrophication, which would have far-reaching ecological influence and should be thus worthy of more attention.