| 摘要: |
| 为了解太平洋大眼金枪鱼(Thunnus obesus)和黄鳍金枪鱼(Thunnus albacares)主要作业渔场次表层关键环境变量时空分布特征, 作者采用2007～2012 年Argo 剖面浮标数据, 分析了太平洋大眼金枪鱼和黄鳍金枪鱼延绳钓主要作业渔场区温跃层特征参数、12℃和距表层海温8℃(Δ8℃)等值线信息。研究表明, 温跃层上界深度和温度以及Δ8℃等深线具有明显的季节性变化。温跃层上界深度呈现出冬深、夏浅的季节性变化特征, 大致呈纬向带状分布。1～3 月份, 北太平洋从东到西温跃层上界深度值都超过90 m, 同期10°S 以南的海域均低于60 m; 7～9 月份则相反。在太平洋150°W 以西, 20°S～20°N 区域, 温跃层上界温度全年在28℃以上。8℃等深线显示在东部太平洋, 一块低值区域(<150m)由东海岸向西海岸延伸; 在20°N 以北和20°S 以南的高值区域(>250m)表现出冬深、夏浅的季节性变化特征。温跃层下界深度图显示有两块高值区域(深度大于280m)从西向东, 由低纬度向高纬度漂移; 在东部太平洋, 两个高值区域之间的纬向区域常年存在一块下界深度低值区域(<140m)。与下界深度类似, 温跃层下界温度也有两块低温区域(<12℃)从西向东, 由低纬度向高纬度漂移。在该低温区域的外侧舌状区域,下界温度超过17℃; 东部太平洋在13～15℃。在15°N 以北和15°S 以南12℃等深线超过400 m, 呈舌状; 赤道东部太平洋, 一块300 m 深的细长舌状区域由东向西延伸。在上述区域之间, 12℃等深线的深度值低于200 m。温跃层下界深度和温度, 以及12℃等深线则没有明显的季节性变化。分析结果初步揭示了太平洋金枪鱼主要作业渔场温跃层上界温度、12℃和Δ8℃等值线信息分布特征, 为金枪鱼实际生产作业提供理论参考。 |
| 关键词: 太平洋 大眼金枪鱼(Thunnus obesus) 黄鳍金枪鱼(Thunnus albacares) 温跃层 次表层 季节变化 |
| DOI：10.11759/hykx20140327001 |
| 分类号: |
| 基金项目:上海市自然科学基金项目(14ZR1449900); 国家科技支撑计划项目(2013BAD13B01); 上海市科技创新行动计划资助项目(12231203901) |
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| Seasonal variability of key subsurface environmental parameters in tuna fishing ground in the Pacific Ocean |
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| Abstract: |
| In order to investigate the spatial and temporal pattern of key subsurface environmental parameters in the fishing ground of Thunnus obesus and Thunnus albacares in the Pacific Ocean, we evaluated the monthly distributions of depths of these key parameters in the longline fishing grounds by using Argo profile buoy data from 2007 to 2012. These parameters include depths of 12℃, Delta 8℃ (the 8℃ temperature difference to sea surface temperature (SST)), upper boundary and lower boundary of the thermocline, and temperatures of the upper and lower boundaries of the thermocline. Our results showed that obvious seasonal zonal striped distributions were found in the upper boundary depth, temperature of the thermocline and Delta 8℃ which has the depth pattern by deep in winter and shallow in summer. From January to March, the upper boundary depth is deeper than 90 m to the north of the Equator, while shallower than 60 m to the south of 15°S. The opposite happens from July to September. The upper boundary temperature is more than 28℃ between 20°S～20°N and west of 150°W. The depth of Delta 8℃ shows seasonal variation: shallower than 150 m in the eastern equator Pacific with westward distribution, and deeper than 250 m to the north of 20°N and to the south of 20°S. The high value (>280 m) of the lower boundary depth of thermocline shaped northeastern drifts from the equator to high latitude. And a shallow depth region occurred between the deeper depth regions in the eastern Pacific Ocean. Moreover, the same pattern was found in the lower boundary temperature of thermocline. Besides the high value shape, the lower boundary temperature is higher than 17℃. The lower boundary temperature is between 13～15℃ in the eastern Pacific. The isothermal depth of 12℃ is deeper than 400 m to the north of 15°N and to the south of 15°S. The isothermal depth of 12℃ is about 300 m in eastern Pacific like tongue East-West distribution. Between the two areas, the isothermal depth of 12℃ is shallower than 200 m. The topography of the lower boundary depth and the temperature of the thermocline and the isothermal depth of 12℃ showed little seasonal variability on the annual mode. Our primary results suggest that these environmental parameters are applicable for the longline tuna fishery in the Pacific Ocean. |
| Key words: The Pacific Ocean Thunnus obesus Thunnus albacares thermocline subsurface environmental seasonal variation |
