摘要
2005年9月15日-12月12日,金枪鱼延绳钓渔船"华远渔18、19号"对印度洋公海进行了金枪鱼渔业调查。利用多功能水质仪(XR-620)、温盐深仪(CTD SBE37SM)和微型温度深度计(TDR-2050)等获取海洋环境数据,得出作业海域的温跃层深度和强度,结合每天作业时记录的渔获数据,分别计算黄鳍金枪鱼和大眼金枪鱼在温跃层内和深水层的渔获率,研究温跃层与黄鳍金枪鱼和大眼金枪鱼渔获率之间的关系。结果表明:(1)2艘船分别有60.9%和60.0%的作业天数中,温跃层内黄鳍金枪鱼渔获率较高,"华远渔18号"船在温跃层内和温跃层以下的平均渔获率分别为18.22尾每千钩和6.04尾每千钩,"华远渔19号"船温跃层内和温跃层以下平均渔获率分别为2.22尾每千钩和1.31尾每千钩。通过t-检验成对双样本均值分析,温跃层以内和温跃层以下黄鳍金枪鱼总平均渔获率有显著性差异(P=0.02<0.05),温跃层以内比温跃层以下的渔获率明显要高;(2)2艘船分别有69.6%和100%的作业天数中,温跃层以下水深大眼金枪鱼渔获率较高,"华远渔18号"温跃层以内和温跃层以下平均渔获率分别为4.18尾每千钩和4.88尾每千钩。"华远渔19号"温跃层以内和温跃层以下平均渔获率分别为0.10尾每千钩和2.57尾每千钩。大眼金枪鱼渔获率在温跃层以下水深较高。通过t-检验成对双样本均值分析,温跃层以内和温跃层以下大眼金枪鱼总平均渔获率无显著性差异(P=0.07>0.05),但对"华远渔19号"船的渔获率数据经t-检验发现大眼金枪鱼在温跃层以内和温跃层以下的渔获率有显著性差异(P=0.00<0.05)。
It can improve our understanding of their behavior characteristics to analyze and identify the relationships between the thermocline and the vertical distribution of yellowfin tuna and bigeye tuna. It also provides critical information for fisheries to enhance the catch rate of the targeting species, fisheries management and resource conservation. Yellowfin tuna and bigeye tuna seem to exhibit nearly opposite approaches to their shared environment. Yellowfin tuna spend their days making excursions from around the top of the thermocline, both up and downward. Their nights are spent near the surface, diving down into the emergent scattering layer to feed. Bigeye tuna swims upward from the cooler depths to stay with their food resources. The depth which bigeye tuna inhabited is usually greater than that of yellowfin tuna. The difference in temperature between the surface layer and waters below the thermocline may be limiting the vertical movements of the tropical tuna. The thermocline is a water column at which the rate of decrease of temperature with increase of depth is much greater compared with those of above and below. The thermocline limits the vertical distribution of yellowfin tuna and bigeye tuna, so their catch rates are affected by the thermocline. A survey on tuna fishing ground has been carried out aboard of the longliners, Huayuanyu No. 18 and No. 19 in the high seas of the Indian Ocean from September 15th to Dec. 12th, 2005. The actual measured environmental data of the fishing area were obtained using Submersible Data Logger XR-620, TDR （2050） （RBR Co., Canada） and SBE37SM （CTD, SeaBird Co., USA）, the depth and intensity of the thermocline could be estimated by these data, and combined with the catch data recorded everyday, the catch rates of yellowfin tuna and bigeye tuna in two different depth layers （the thermocline and the deep water layer ） were calculated respectively. The relationships between the thermocline and catch rate of yellowfin tuna and bigeye tuna were analyzed. The r
出处
《水产学报》
CAS
CSCD
北大核心
2008年第3期369-378,共10页
Journal of Fisheries of China
基金
农业部2005年度公海渔业资源探捕项目资助(技05-30)
上海市重点学科建设项目资助(T1101)
关键词
黄鳍金枪鱼
大眼金枪鱼
温跃层
渔获率
延绳钓
印度洋公海
Thunnus albacares
Thunnus obesus
thermocline
catch rate
longline
the high seas of the Indian Ocean
