尖笔帽螺(Creseis acicula)研究进展及其在大亚湾暴发机制初探*

尖笔帽螺(Creseis acicula)隶属软体动物门翼足目, 是营浮游生活的大洋暖水种, 在世界多个海域尤其是印度洋沿岸多次暴发, 但此前在中国海域未有暴发记录。2020年6—7月, 在大亚湾西南部核电站邻近海域监测到尖笔帽螺大规模暴发, 整个过程持续约1个月, 高峰期密度达到5600个·m^-3, 是迄今为止已报道的该种暴发的最高密度。尖笔帽螺的高密度区均集中在西南部沿岸区域, 尤其是岭澳核电站冷源取水口附近, 对核电冷源运行安全造成了严重影响, 引起政府、企业、科研界和社会公众的高度重视。鉴于目前对尖笔帽螺的暴发机制还知之甚少, 文章综述了尖笔帽螺生物生态学特征研究进展, 阐述了大亚湾尖笔帽螺的暴发和消退过程, 并基于对此次暴发事件的跟踪监测, 初步探讨其暴发机制及其生态效应, 认为核电站冷却水的温升效应、降雨引起的海水盐度波动以及浮游植物数量升高可能是诱发其暴发的重要因素。

A review on ecological characteristics of Creseis acicula and preliminary analysis on its outbreak triggers in Daya Bay

Creseis acicula, also known as sea butterfly, is marine gastropod adapted to pelagic life. C. acicula is a warm-water marine species and widespread in the world. C. acicula blooms have been found in many waters of the world, particularly in the Indian Ocean. Its bloom was never recorded in the seas of China until 2020. From June to July 2020, an unprecedented outbreak of C. acicula was observed the southwest coast of Daya Bay, Southern China Sea. This bloom lasted for approximately one month. The peak density was as high as approximately 5600 ind·m^-3, which is the highest value ever recorded in the world. The C. acicula population was most abundant in waters adjacent to the outflow of Daya Bay nuclear power plant (NPP) located at the southwest of the bay. The outbreak puts a serious threat to the safety of the NPP operation, and therefore has attracted great attentions from the government, scientists and the public. We conducted a continuous monitoring on this event. Since there is very limited information on outbreak mechanisms, we briefly reviewed related research on bio-ecological characteristics of C. acicula; then, we introduced its development progresses in Daya Bay and preliminarily discussed the possible triggers for this outbreak. We assume that the temperature rise due to thermal discharge from the cooling water of the NPP, the fluctuation of seawater salinity caused by rainfall, and the increase in phytoplankton concentration could be the possible factors for this C. acicula bloom.