摘要
采用1998年8月、1999年8月长江口及其临近海域(121°15′E—122°41′E,30°00′N—31°30′N)的调查资料,对采集到的水母样品进行分析,探讨水母的分布特征以及影响因素。结果表明:调查海域共出现水母21种,其中水螅水母15种,管水母4种,栉水母2种;可分为近岸低盐性、低盐河口性和大洋暖水性3个生态类群,其中近岸低盐物种达60%以上,分布范围广,低盐河口类群仅出现于受长江冲淡水影响明显的低盐水域,而大洋暖水类群分布于受外海水影响较大、盐度较高、离岸较远的区域;优势种为贝氏拟线水母、球型侧腕水母、单囊美螅水母、五角水母、拟细浅室水母和双生水母。总体分布特征为:从长江口向外伴随着盐度的逐渐增大,丰度逐渐升高,在长江冲淡水与外海水交汇的舟山渔场西部水域,丰度最大;水母的出现种类、丰度均与东海外海水、长江冲淡水2大水系的配置有关:外海水越强,整个区域平均盐度较高,出现的水母种类、丰度均高;反之,长江冲淡水势力控制范围大,平均盐度明显降低,物种少且丰度低。
Based on the investigations at the Yangtze River Estuary and its adjacent waters （ 121°15′E-122°41′E,30°00′N-31°30′N） in August of 1998 and 1999, the distribution characteristics of medusa and their affecting factors were studied. A total of 21 medusa species including 15 of Hydromedusae, 4 of Siphonophore, and 2 of Ctenophore were identified, which could be classified into three ecological groups, i. e. , low salinity neritic group, low salinity estuarine group, and oceanic warm water group. The first group distributed widely, the second group was more prevalent in lower salinity estuary, and the third one only appeared in higher salinity offshore area. The dominant species were Nemopsis bachei, Pleurobrachia globosa, Clytia folleata, Muggiaea atlantica, Lensia subtiloides, and Diphyes chamissonis. With the increase of salinity from the Yangtze River Estuary to the offshore, the abundance of medusa increased gradually, being the highest in western Zhoushan Fishing Ground where the waters from the Yangtze River and open sea were mixed together. Water mass had significant effects on the distribution of medusa. The more severe the open seawater invaded, the higher the abundance of medusa was. In contrast, when the whole area was under the control of diluted water from Yangtze River, the abundance of medusa was lower.
出处
《生态学杂志》
CAS
CSCD
北大核心
2008年第9期1510-1515,共6页
Chinese Journal of Ecology
基金
国家自然科学基金重大资助项目(NSFC30490230WP4-003)
关键词
水母
长江口
生态类群
优势种
时空分布
medusa
Yangtze River Estuary
ecological group
dominant species
temporal and spatial distribution.
