春季福建北部海域浙闽沿岸流消亡期浮游桡足类种类组成及其分布

根据2009年4月在福建北部海域（24°47＇17.0″～26°48＇02.9″N;119°29＇36.0″～120°57＇13.8″E）所采集的浮游桡足类样品,对该海域浮游桡足类的种类组成、个体密度、优势种及其分布特点进行了分析探讨,并与2007年＂908专项＂春季航次相应调查范围的资料相比较,探讨其年际变化及内在原因.本航次共记录浮游桡足类48种,哲水蚤目种类数最多,优势种为中华哲水蚤（Calanus sinicus）和平滑真刺水蚤（Euchaeta plana）.调查区浮游桡足类的平均丰度为231.96 ind.m-3,其平面分布呈现近海大于外海,北部海区高于南部海区的趋势,种类数平面分布呈现调查区的南部多于北部,东部大于西部近岸海区.浮游桡足类的群落结构与以往的调查结果基本一致,优势种突出、多样性指数较低;但其平面分布存在着年际变化,＂908专项＂春季航次浮游桡足类的高密度中心分布在三沙湾至闽江口之间的附近海域,而本航次的高密度中心位于三沙湾外部的近岸海域,这可能与考察期间受东北季风强度所左右的浙闽沿岸流强弱有关.根据浮游桡足类的生态习性本航次记录的浮游桡足类分为沿岸暖水,沿岸暖温和热带大洋性3个生态类群,沿岸暖水性和热带大洋性类群的种数多,沿岸暖温性类群个体密度占优势,本研究还对浮游桡足类种类数、多样性指数及其丰度分布与环境的关系进行了讨论,调查海区浮游桡足类群落的种类数以及多样性主要受温度和盐度的影响,并随着温度、盐度的增高而增加.

Species Composition and Distribution Characteristics of Pelagic Copepods in the Northern Sea of Fujian During Withdraw of Zhe-Min Coastal Current

Based on oceanographic survey data in April 2009 in the north central Taiwan Strait,ecological characteristics such as species composition, individual density, dominant species and distribution were analyzed. The results were compared with the same area survey in spring 2007 for discuss the annual variety. The result shows that 48 pelagic copepods species have been recognized, and most of them belongs to Calanodia. The higher species number occurs in southern and eastern area. The average density of pelagic copepoda was 231.96 ind·m^-3. As to the horizontal distribution, the coast and northern areas are higher than those of eastern and southern areas of the density of pelagic copepods which are dependent on the dominant species Calanus sinicus and Euchaeta plana. The community structure of pelagic copepoda was same to the other survey result, which shows low biodiversity index with remarkable dominant species. Owing to the Zhe-Min coastal current effect, the higher density distribution is different in 2007 and 2009.As to the ecological character, all the copepoda in this paper belong to warm-water, warm-temperature and tropic oceanic groups. Warm-water and tropic oceanic groups are the dominant groups of the pelagic copepods composition. When it comes to density, warm-temperature group is the dominant. The relationship of species number, diversity index and abundance with the environment were also discussed in this paper. The result showed that the pelagic copepoda species number and diversity would increase with the temperature and salty increase.