Species Composition and Abundance Distribution of Meso- and Micro-copepods and Their Relationships with Environmental Factors During Dry and Wet Seasons in the Pearl River Estuary

中小型桡足类是河口区浮游动物的重要组成部分.根据珠江口枯水期(2013年11月)和丰水期(2014年8月)24个站位的调查资料,对中小型桡足类种; 类组成、丰度分布和优势种等特征进行了研究.枯水期和丰水期中小型桡足类分别出现60和40种,以河口和近岸类群为主.根据表层盐度变化将珠江口分为Ⅰ、; Ⅱ、Ⅲ区,桡足类种类分布具有显著的河口特征,枯水期和丰水期盐度均为Ⅲ区>Ⅱ区>Ⅰ区.相关性分析结果显示,桡足类种类数与盐度呈极显著正相关.桡足类; 丰度时空分布差异显著,丰水期(10 809. 05 ind/${{\rm{m}}^{\rm{3}}}$)显著高于枯水期(1 371. 20; ind/${{\rm{m}}^{\rm{3}}}$),且在2个水期均以I区丰度最高.强额孔雀哲水蚤(Parvocalanus; crassirostris)和中华异水蚤(Acartiella; sinensis)在2个水期均为主要优势种,其空间分布亦与盐度密切相关.研究结果表明盐度是影响珠江口中小型桡足类种群结构的关键非生物环境因子.Meso- and micro-copepods are the major species of estuarine zooplankton.; Based on investigations of 24 stations in the Pearl River Estuary in; November 2013 (dry season) and August 2014 (wet season),the species; composition,abundance distribution and dominant species of meso- and; micro-copepods were studied.Results showed that there were 60 and 40; copepod species identified in the dry and wet season,respectively,mostly; belonging to the estuarine and neritic groups.In our study,the Pearl; River Estuary was divided into three regions according to its surface; salinity.The Distributions of species number in both dry and wet seasons; were Region Ⅲ >Region Ⅱ >Region I,displaying a remarkable characteristic; estuarine distribution.The species number of copepod was significantly; correlated with salinity.The abundance of copepod was found varying with; time and geographic locations.The average copepod abundance in the wet; season (10 809. 05 ind/${{\rm{m}}^{\rm{3}}}$) was much higher than in; the dry season (1 371. 20 ind/${{\rm{m}}^{\rm{3}}}$), and in both; seasons Region I had the highest copepod abundance.Moreover, the two; copepods of Parvocalanus crassirostris and Acartiella sinensis were; found dominant in both seasons,and their distributions were; significantly correlated with salinity.In conclusion,salinity was the; key abiotic factor influencing copepod population structure in the Pearl; River Estuary.广东省渔业生态环境重点实验室2015年开放课

Study on a Cosmic-ray-produced Silicon-32 as a Tracer for Ocean Processes

32SI是一种宇生放射性核素,半衰期约150年。由于其来源单一、生产速率相对恒定,并具有与稳定硅相同的化学和生物特性,一直被视为研究50~1 000年尺度海洋过程的一个理想的计时钟和示踪剂。本文介绍了32SI在海洋学的应用,主要包括示踪近岸和大洋水体的混合,河口和大洋中硅的地球化学行为和循环,深海海底颗粒物的混合,及利用其计算沉积速率/混合速率,建立年代序列来反映环境变化的信息。The isotope silicon-32,with a half-life of approximately 150 years,is a cosmic-ray-produced radioactive nuclide in the atmosphere.Due to its single source and the relatively constant production rate,silicon-32 with its chemical and biological characteristics like the other stable silicon isotopes always has been seen as an ideal clock and tracer which has the potential to fill the dating time-gap and to understand marine from50 to 1 000 years geochemical-geophysical processes,e.g.the seawater mixing process in offshore and ocean,the geochemistry and cycle of silica in estuary and ocean,the particles mixing process in the deep sea bed,as well as the estimation of the sediment depo-sition rate and the establishment of the time-sequence to reflect the past marine environmental changes.国家海洋公益性行业科研专项项目(201105003