深圳湾海域赤潮生物演变及赤潮预警关键因子分析  

Analysis on the key factors for the population evolution and early warning of harmful algal blooms based on an algal bloom in Shenzhen bay, the South China Sea

作　　者：李丽 马方方 翟晓辉 杨伟思 叶鹏浩 刘悦 LI Li;MA Fangfang;ZHAI Xiaohui;YANG Weisi;YE Penghao;LIU Yue(Marine Development Research and Promotion Center of Shenzhen,Shenzhen 518067,China;Research Institute for Environmental Innovation(Suzhou)Tsinghua,Suzhou 215163,China)

机构地区：[1]深圳市海洋发展研究促进中心,深圳518029 [2]清华苏州环境创新研究院,苏州215163

出　　处：《生态科学》2022年第3期82-89,共8页Ecological Science

基　　金：国家自然科学基金项目(41606176)。

摘　　要：2020年5月初,深圳湾海域发生近5年来首次赤潮,面积达到6km^(2),前期赤潮优势种为中肋骨条藻(Skeletonema costatum),后期转变为赤潮异弯藻(Heterosigma akashiwo)。布放于深圳湾海域的海洋环境综合浮标自动监测到了赤潮发生过程的海水水质和生态数据变化:赤潮发生前(4月底)硝酸盐和磷酸盐均大幅升高;赤潮发生期间,叶绿素a浓度迅速升高,最高值达到127.1μg·L^(-1)(5月2日),海水温度持续升高,盐度整体下降;5月4日开始,赤潮逐渐消散,当日水温日均值达到28℃以上,风力也开始升高,盐度则继续降低。经研究分析,本次深圳湾赤潮的主要调控因素可能是水温,活性磷酸盐大幅升高可能是引发中肋骨条藻大规模增殖的诱因,而赤潮后期的陆源水体输入导致的悬浮物增加导致了赤潮快速消亡。本次赤潮优势种从硅藻到针胞藻的转变,主要原因可能是赤潮前期磷酸盐快速消耗导致的磷供应不足。通过数据分析发现,近十几年来,深圳湾海域赤潮生物逐渐从硅藻转变为甲藻及其他藻类,其原因与海域氮磷比持续升高、磷成为限制因子有关,故海域赤潮监测预警应重点关注磷酸盐的变化。A harmful algae bloom was recorded in Shenzhen Bay, the South China Sea, in May 2020. The causative specie was Skeletonema costatum in the first beginning, then shifted to Heterosigma akashiwo. The data from the water quality buoy in the area showed that concentrations of nitrate and phosphate increased significantly before the outbreak of the bloom.During the bloom, the concentration of chlorophyll a reached its maximum value to 127.1 μg· L^(-1) on May 2, accompanied by a continuously rising temperature and a decreasing salinity. In the process of the bloom disintegration, water temperatures kept increasing to as high as 28 ℃, whileas the salinity exhibited a continuous decrease. Analytic results indicated that temperature might be the dominant factor for the HAB. The rapid increase of phosphate imput might be the causative factor for the Skeletonema costatum bloom, whileas the increases of suspended matters from riverine input promoted the rapid decline of the bloom. The shift of causative species from diatom to raphidophyte during the bloom was speculated to the consumption of large amount of phosphate during the HAB. The results from a long term data analysis showed that HAB causative species shift from diatoms to dinoflagellates and other taxas in the last decade was due to continuously increase of N/P ratio. Phosphorus is a limited nutrient in the area. Authors suggest that monitoring of phosphate is of the first importance for the early warning of HABs in Shenzhen Bay.

关 键 词：深圳湾 磷酸盐 赤潮 中肋骨条藻 赤潮异弯藻 

分 类 号：X55[环境科学与工程—环境工程]