摘要
为了解印度洋热带海域黄鳍金枪鱼(Thunnus albacares)延绳钓适宜渔获水温的等温线时空分布,分析黄鳍金枪鱼适宜的垂直和水平空间分布范围,采用Argo浮标剖面温度数据重构印度洋热带海域16°C和距海洋表层水温8°C(Δ8°C)的月平均等温线场,网格化计算了16°C和Δ8°C等温线深度值和下界深度差,并结合印度洋金枪鱼委员会(IOTC)黄鳍金枪鱼延绳钓渔业数据,绘制了16°C和Δ8°C等温线深度与月平均单位捕捞努力量的渔获量(CPUE)的空间叠加图,用于分析热带印度洋黄鳍金枪鱼中心渔场CPUE时空分布和高渔获率水温的等温线时空分布关系。结果表明,高值CPUE的分布表现出明显的季节性变化。16°C等温线,在东北季风期间,高值CPUE出现的地方深度值大多小于200m;西南季风期间,在15°—25°S深度可到达250m,在130—190m深度全年有高值CPUE集中出现,深度值超过300m的地方CPUE普遍较小。Δ8°C等温线,高值CPUE出现的地方深度值大多小于175m,主要在100—170m;西南季风期间,在15oS以南区域,150—300m深度,也有高值CPUE区域出现,全年深度值超过300m的地方CPUE普遍较小。全年在15oS以北纬向区域,高渔获率的垂直分布深度更加集中,在西南季风期间尤其明显。采用频次分析和经验累积分布函数计算其最适次表层环境因子分布,16°C等温线120—209m;Δ8°C等温线80—159m;与下界深度差:16°C等温线0—59m;海表以下8°C等温线50—119m。文章初步得出热带印度洋黄鳍金枪鱼中心渔场适宜的水平、垂直深度值分布区间,结果可以辅助寻找中心渔场位置,同时指导投钩深度,为热带印度洋黄鳍金枪鱼实际生产作业和资源管理提供理论支持。
To investigate the distribution of isothermal depth in subsurface temperature for yellowfin tuna(Thunnus albacares) fishing grounds in the tropical Indian Ocean, figures of isothermal depths at 16°C and Δ8°C(temperature difference between 8°C and sea surface temperature, and their spatial overlay maps were plotted. The figures were depicted by monthly temperature profile data from Argo buoys and the monthly CPUE(catch per unit effort) of yellowfin tuna longlines data from IOTC. Meanwhile, depth difference between 16°C and Δ8°C with the lower boundary depth of thermocline was also calculated to find possible relationship between yellowfin tuna vertical distribution and thermocline depth. Result suggests that high CPUE distribution showed obvious seasonal variation. The high CPUE appeared in the ground where the 16°C isothermal depth was shallower than 200 m during northeast monsoon, and reached to 250m in the latitude area between 15°—25°S during the southwest monsoon. In addition, the CPUE concentrated between 130 and 190m, while CPUE became small in depth of over 300 m. The high CPUE appeared in the place where the Δ8°C isothermal depth was shallower than 175m and most distributed between 100—170m; the high CPUE appeared between 150 and 300m in the south of 15°S during southwest monsoon while the value of CPUE was low in the depth of more than 300 m. The vertical distribution of high hook rate concentrated in the area to the north of 15°S, especially during the southwest monsoon. Frequency analysis and the empirical cumulative distribution function were used to compute the optimum range of subsurface factors. The optimum depth range for 16°C isothermal depth was 120—209 m and that for Δ8°C was 80—159 m. The optimum depth difference ranges to the low boundary of thermocline were 0—59m for 16°C isothermal depth and 50—119m for Δ8°C. The findings were confirmed with the Kolmogorov-Smirnov test. However, the suitable distribution interval and vertical depth rang in the central fishing ground of yellowfin tuna determined in this study are preliminary, and we hope these results may provide a reference for the longline production operation and management in this marine resource.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2014年第2期281-290,共10页
Oceanologia Et Limnologia Sinica
基金
国家科技支撑计划项目
2013BAD13B01号
上海市科技创新行动计划项目
12231203901号
资源与环境信息系统国家重点实验室开放基金
2010KF0005SA号
中国水产科学研究院基本科研业务费资助
2012A1201号
2013A0201号
中央级基本科研业务费
2012T07号
