摘要
为了解热带大西洋黄鳍金枪鱼(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热带大西洋13℃和距海洋表层水温8℃(Δ8℃)的月平均等温线场,网格化计算了13℃和Δ8℃等温线深度值和温跃层下界深度差,并结合大西洋金枪鱼会委员(International Commission for the Conservation of Atlantic Tunas ICCAT)的黄鳍金枪鱼延绳钓渔业数据,绘制了13℃和Δ8℃等温线深度与月平均CPUE的空间叠加图,用于分析热带大西洋黄鳍金枪鱼中心渔场单位捕捞努力渔获量(Catch per unit effort CPUE)时空分布和次表层环境季节性变化关系。结果表明,13℃等温线,在高值CPUE出现的海域深度值大多小于250 m,主要在170—249 m,深度值超过250 m的海域CPUE普遍较小。5°S—9°N区域,Δ8℃等温线高值CPUE出现的海域深度值大多小于150 m,主要在50—139 m;7—10月份在南半球的非洲西海岸,在Δ8℃等温线深度值为150—350 m的海域也会出现中心渔场。全年在低纬度区域,高渔获率的垂直分布深度更加集中。13℃等温线影响热带大西洋黄鳍金枪鱼的空间分布,温跃层下界温度影响黄鳍金枪鱼的垂直分布。采用频次分析和经验累积分布函数计算其适宜次表层环境因子分布,13℃等温线180—240 m;Δ8℃等温线50—139 m;与下界深度差:13℃等温线-70—29 m;海表以下8℃等温线30—149 m。文章初步得出热带大西洋黄鳍金枪鱼适宜的水平、垂直深度分布区间。结果可以辅助渔情预报,为热带大西洋黄鳍金枪鱼实际生产作业和资源管理提供参考依据。
In order to investigate the distribution of the yellowfin tuna （Thunnus albacares） in the fishing grounds in the tropical Atlantic Ocean, the isothermal distribution of subsurface temperatures in the yellowfin tuna fishing grounds was evaluated. The depths of 13℃ and 8℃ isotherm from the sea surface temperature （SST） （Delta 8℃）, were plotted on spatial overlay maps using data collected on a monthly basis from Argo buoys and monthly CPUE data （catch per unit effort） from Thunnus albacares long-lines supplied by the International Commission for the Conservation of Atlantic Tunas （ICCAT）. In addition, the differences in depth between the 13℃ and delta 8℃ isolines at the lower boundary of the thermocline were computed to determine the relationship between Thunnus albacares vertical distribution and thermocline depth. The overlay maps suggest that the delta 8℃ isothermal depth distribution showed obvious seasonal variation, roughly in the zonal striped distribution on the annual mode. The spatial distribution of the delta 8℃ isothermal depth is deep in winter and shallow in summer. The delta 8℃ isothermal depth is shallow, lying at 150 m in the low latitude area throughout the year. The topography of the 13℃ isothermal depth showed little seasonal variation. The 13℃ isothermal depth was greater than 250 m to the north of the slope, which started 15°N of West Africa and ended 10°N of South America, and to the south of the slope, which started from 10°S of South America and ended 30°S of West Africa. In the triangular area between these two slopes, the 13℃ isothermal depth distribution ranged from 150 m to 200 m. The CPUE is highest in areas where the 13℃ isothermal depth was shallower than 250 m （mode： 170-249 m）. Conversely, if the depth is greater than 250 m, the CPUE tends to be low. Similarly, the highest CPUEs were observed in areas where the delta 8℃ isothermal depth was shallower than 150 m （mode： 50-139 m） in the latitude area between 5°S and 10°N throughout the year, whereas the delta 8℃ isothermal depth reached 150-350 m offshore of the west coast of Africa in the southern hemisphere from July to October. The vertical distribution of high hook rates was concentrated in the area between 5°S and 10°N. The horizontal distribution of Thunnus albacares in the tropical Atlantic Ocean was affected by the 13℃ isothermal depth, and the vertical distribution of Thunnus albacares was affected by the low boundary temperature and depth of the thermocline. Frequency analysis and the empirical cumulative distribution function were used to compute the optimum range of subsurface factors. The optimum ranges for 13℃ and delta 8℃ isothermal depths were 180-240 m and 50-139 m, respectively. The optimum depth difference ranges were 70-29 m for 13℃ isothermal depths and 30-149 m for delta 8℃ isothermal depths. The results were confirmed by using the Kolmogorov-Smirnov test. The distribution interval and vertical depth range for the central fishing ground of Thunnus albacares was documented, and the results provide a reference for improving the efficiency of long-line fleet and resource management.
出处
《生态学报》
CAS
CSCD
北大核心
2015年第15期5040-5049,共10页
Acta Ecologica Sinica
基金
上海市自然科学基金(14ZR1449900)
科技支撑计划项目(2013BAD13B01)
上海市科技创新行动计划(12231203901)
