Environmental effects on yellowfin tuna catch by the Taiwan longline fishery in the Arabian Sea
Environmental effects on yellowfin tuna catch by the Taiwan longline fishery in the Arabian Sea
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DOI：
10.1080/01431161.2012.685971
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发表时间：
2012-01-01
影响因子：
3.4
通讯作者：
Chang, Yi
中科院分区：
文献类型：
--
作者：
Lan, Kuo-Wei;Lee, Ming-An;Chang, Yi
在这项研究中，我们收集了环境变量，调查其对单位努力量（CPUE）的黄鳍金枪鱼在阿拉伯海在1980-2005年期间的渔获量的影响。我们使用了先进的时间序列分析，包括一个状态空间的方法来消除季节性，和小波分析来调查瞬态关系。对于大尺度的环境影响，我们使用偶极子模式指数（<$）来代表印度洋偶极子;对于当地的环境因素，我们调查了海表温度（SST），温跃层深度和叶绿素a（chl-a）浓度。引起CPUE年际变化的主要因子可能随时间而变化。从80年代初到90年代中期，CPUE与SST、SST呈显著正相关。与chl-a的相关性也很强，特别是1998-2005年常规延绳钓渔业的chl-a与chl-a呈长期正相关，周期为2年。常规和深延绳CPUE被发现有显着的连贯性与温跃层深度具有3年的周期。这种关系是相反的迹象，浅的温跃层深度产生了高CPUE的常规延绳钓渔业和深温跃层深度造成了高CPUE的深延绳钓渔业。
In this study, we collected environmental variables to investigate their effects on the catch per unit effort (CPUE) of yellowfin tuna in the Arabian Sea during the period 1980-2005. We used an advanced time series analysis, including a state-space approach to remove seasonality, and wavelet analysis to investigate transient relationships. For large-scale environmental effects, we used the dipole mode index (DMI) to represent the Indian Ocean dipole; for local environmental factors, we investigated sea surface temperature (SST), thermocline depth and chlorophyll-a (chl-a) concentration. The main factors causing interannual variations in the CPUE might change with time. CPUE showed positive correlations with SST and DMI from the beginning of the 1980s to the middle of the 1990s. It also showed a significant coherence with chl-a, especially a long-term positive correlation for the regular longline fishery in 1998-2005 with a periodicity of 2 years. Both regular and deep longline CPUEs were found to have significant coherence with thermocline depth having a periodicity of 3 years. The relations were of opposite signs such that the shallow thermocline depth produced a high CPUE for the regular longline fishery and deep thermocline depth caused a high CPUE for the deep longline fishery.