南极海冰变动对西南大西洋阿根廷滑柔鱼资源丰度及空间分布的影响

南极海冰变化会是重要的大尺度环境变化,会对海洋环境及多种生物产生直接或间接影响。南极海冰覆盖范围(Sea Ice Extent)可以作为指示南极海冰变化的指数,本文探究其对西南大西洋阿根廷滑柔鱼(Illex argentinus)渔场的影响。根据2013-2018年1-6月中国鱿钓科学技术组提供的西南大西洋公海渔场阿根廷滑柔鱼捕捞数据、南极海冰覆盖范围数据以及作业渔场5m、55m、95m、195m海水温度数据,以单位捕捞努力量渔获量(CPUE)表征资源丰度,本文探究了南极海冰覆盖范围、不同水深海水温度对阿根廷滑柔鱼渔场变动的影响。结果发现,阿根廷滑柔鱼的捕捞量、CPUE、南极海冰覆盖范围与不同深度海水温度均有明显的年间及月间变化。相关分析法表明,南极海冰覆盖范围与CPUE在年间与月间变化上均为正相关；海冰覆盖范围与5m海水温度在年间与月间变化上均为负相关,而与95m海水温度在月间变化上呈正相关。依据频率分布法估算了不同海水深度滑柔鱼各月适宜和最适温度范围,不同深度的各月最适温度范围占渔场总面积比例与海冰覆盖范围呈正相关关系,推测海冰覆盖范围会影响不同深度的栖息地适宜比例,并进一步影响阿根廷滑柔鱼资源丰度。研究表明,南极海冰覆盖范围变化会显著影响阿根廷滑柔鱼渔场内不同水层的水温,进而影响其渔场的分布及资源丰度。

Influence of Antarctic sea ice variation on abundance and spatial distribution of Argentine shortfin squid Illex argentinus in the southwest Atlantic Ocean

Antarctic sea ice changes can have direct or indirect effects on the environments and a variety of marine organisms. The Sea Ice Extent was considered as an index to indicate changes in Antarctic sea ice, in this study, its impacts on fishing ground of Argentine shortfin squid Illex argentinus in the Southwest Atlantic Ocean were explored. In this study, the catch per unit effort (CPUE) was used to indicate squid abundance, we evaluated the influences of sea ice extent and sea water temperature in different depths on stock variations of Illex argentinus, based on the fishery data from January to June during 2013-2018 obtained from the Chinese squid-jigging Science and Technology Group as well as the sea ice extent data and the seawater temperature data of 5m, 55m, 95m and 195m depth on the fishing ground. The results indicated that the catch, CPUE, sea ice extent, sea water temperature in different depths exhibited significant annual and monthly variations. The correlation analysis suggested that Antarctic sea ice extent was positively correlated with CPUE at an annual and monthly scale. Sea ice extent was negatively correlated with annually and monthly sea water temperature in 5m, but was positively correlated with sea water temperature in 95m. Based on the histogram analysis, the monthly suitable and the most preferred sea water temperature for Illex argentinus were evaluated in different depths. Positive relationship was found between the monthly percentages of suitable temperature in different depths accounting for the whole fishing ground and the sea ice extent, suggesting that the sea ice extent would affect the proportions of suitable habitats at different depths and further affect the abundance of Illex argentinus. Our findings indicated that sea ice extent has significant impacts on sea water temperature in different depths, and further affect the fishing ground distribution and also squid abundance.