广西北部湾近岸海域近20年赤潮灾害特征分析

Characteristics of Red Tide Disaster in Coastal Waters of Beibu Gulf of Guangxi in Recent 20 Years

关键词:  赤潮预警监测  赤潮灾害  分布特征  赤潮藻种  北部湾

Key words:  red tide warning and monitoring  red tide disasters  distribution characteristics  red tides species  Beibu Gulf

摘要:

本研究对广西北部湾近岸海域2002-2021年发生的20次赤潮灾害进行综合分析，结果表明：近20年广西近岸海域赤潮平均每年发生1次，发生面积约为384 km²，持续时间为3.65 d，主要集中在春夏季，近10年（2012-2021年）相对前10年（2002-2011年）赤潮发生面积增加（18倍）。引发赤潮的生物种类共有10种，其中次数最多的是球形棕囊藻（Phaeocystis globosa），其次是夜光藻（Noctiluca scintillans）、水华微囊藻（Microcystis flos-aquae）和红海束毛藻（Trichodesmium erythraeum），但近10年不断有新的赤潮藻种出现。赤潮发生总数中，有毒或有害赤潮11次，分别为球形棕囊藻4次，夜光藻和水华微囊藻各3次，链状裸甲藻（Gymnodinium catenatum）1次。广西近岸海域赤潮发生的分布范围广，2008年以前主要发生在北海市涠洲岛海域，2008年以后钦州市三娘湾和三墩岛海域、北海市廉州湾及防城港市防城湾陆续开始发生赤潮。通过综合分析近20年北部湾近岸海域赤潮发生和分布的基本特征，为北部湾赤潮预警预报及治理工作提供科学依据。

Abstract:

In this study, 20 red tide disasters occurred in the coastal waters of Beibu Gulf in Guangxi from 2002 to 2021 were comprehensively analyzed. The results showed that the red tide occurred once a year on average in the coastal waters of Guangxi in recent 20 years, with an area of about 384 km² and the duration of 3.65 d, mainly concentrated in spring and summer. The occurrence area of red tide in recent 10 years (2012-2021) increased by 18 times compared with that in the previous 10 years (2002-2011). There are 10 species of organisms causing red tides, among which Phaeocystis globosa is the most frequent one, followed by Noctiluca scintillan, Microcystis flos-aquae and Trichodesmium erythraeum. However, new species of red tide algae have emerged continuously in recent 10 years. Among the total number of red tides, there were 11 toxic or harmful red tides, 4 times of P.globosa, 3 times of N.scintillan and M.flos-aquae, and 1 time of Gyrnnodinium catenatum.Red tides occurred widely in coastal waters of Guangxi. Before 2008, they mainly occurred in Weizhou Island of Beihai city. After 2008, red tides also began to occur in Sanniang Bay and Sandun Island of Qinzhou City, Lianzhou Bay of Beihai City, and Fangchenggang Bay of Fangchenggang City. The basic characteristics of occurrence and distribution of red tides in the coastal waters of Beibu Gulf in recent 20 years are comprehensively analyzed to provide a scientific basis for the early warning forecast and management of red tides in Beibu Gulf.