文献类型： 外文期刊

作者： Zhang Bo ¹ ; Zhao Xianyong ¹ ; Dai Fangqun ¹ ;

作者机构： 1.Minist Agr, Key Lab Sustainable Utilizat Marine Fishery Resour, Key Lab Fishery Resources & Ecoenvironm, Qingdao, Shandong Prov, Peoples R China; Chinese Acad Fishery Sci, Yellow Sea Fisheries Res Inst, Qingdao 266071, Shandong Prov, Peoples R China

关键词： fat content;water content;target strength;acoustic estimation;anchovy;the Yellow Sea

期刊名称：CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY （ 影响因子：1.068； 五年影响因子：0.983 ）

ISSN： 0254-4059

年卷期： 2011 年 29 卷 3 期

页码：

收录情况： SCI

摘要： Anchovy is a key species in the Yellow Sea ecosystem. An accurate estimate of anchovy abundance is vital for the management of the anchovy stock and measurement of the ecosystem response to changes in anchovy abundance. However, the acoustic fish abundance estimate may be biased by 30%-40% if the fat-content induced target strength variation is not taken into account. We measured the monthly variation in the fat content of anchovy (Engraulis japonicus) in the Yellow Sea, and evaluated the potential effect of variation in fat content on the acoustic assessment of anchovy abundance. The fat content of anchovy varied seasonally, with two maxima and two minima in a year. The highest fat content (14.75%) was measured in the pre-spawning period in May, and the lowest fat content (2.48%) was measured during the post-spawning period in October. Fat content appeared to correlate with water content, but not body size. Assuming that the target strength is decreased by 0.2dB for every 1% increase in fat content, the seasonal difference in the target strength of anchovy may be as high as 2.45 dB. Given this, the acoustic abundance estimate may be biased by between 43% and 76%. Our results highlight the need for more information on the changes in fat content of fishes whose abundance is estimated by acoustic surveys.