Marine Chemistry and Environment, Ocean College, Zhejiang University, Zhoushan 316021, China; Key laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
Key laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China; Donghai Laboratory, Zhoushan, China; College of Oceanography, Hohai University, Nanjing, China.
Mar Pollut Bull. 2024 Oct;207:116793. doi: 10.1016/j.marpolbul.2024.116793. Epub 2024 Aug 16.
Phosphorus (P) is an essential biogenic element in ecosystems; but excessive or insufficient P in coastal waters caused by human activities has led to serious ecological issues. However, the understanding of the dynamic processes of different P forms in high turbidity estuaries/bays, as well as their impact on eutrophication and coastal algal blooms, is still relatively limited. To address this issue, we analyzed P dynamics and their impact on eutrophication in Hangzhou Bay (HZB), which is typical of eutrophic and turbid bay worldwide. The concentration of particulate P (PTP) was 3-5 times higher than that of dissolved inorganic phosphorus (DIP). Seasonal sediment resuspension led to the accumulation of suspended particulate matter (SPM) and PTP with regional variation, both maintaining DIP concentrations above 1 μmol/L within the bay. Furthermore, 3000 tons of bioavailable P were retained in the fine-grained SPM, with the potential for outward transport, fueling subsequent harmful algal blooms. A comparative analysis of global coastal waters highlighted that different turbidity levels significantly affect P cycling. Therefore, understanding the relationship between SPM and P in highly turbid waters is crucial for effective management of eutrophication.
磷（P）是生态系统中一种重要的生源要素，但由于人类活动导致的沿海水体中磷的过量或不足，已经引发了严重的生态问题。然而，对于高浑浊度河口/海湾中不同磷形态的动态过程及其对富营养化和沿海藻类水华的影响，我们的了解仍然相对有限。为了解决这个问题，我们分析了杭州湾（HZB）的磷动态及其对富营养化的影响，该湾是世界范围内典型的富营养化和浑浊的海湾。颗粒态磷（PTP）的浓度是溶解无机磷（DIP）的 3-5 倍。季节性底泥再悬浮导致悬浮颗粒物（SPM）和 PTP 的积累，具有区域变化，两者都使海湾内的 DIP 浓度保持在 1 μmol/L 以上。此外，有 3000 吨可利用磷被细颗粒 SPM 保留下来，并有向外输送的潜力，从而引发后续的有害藻类水华。对全球沿海水域的比较分析表明，不同的浑浊度水平会显著影响磷的循环。因此，了解高浑浊度水中 SPM 和 P 之间的关系对于富营养化的有效管理至关重要。
