基于渔业数据的南极磷虾48渔区渔场时空分布

Temporal and Spatial Distribution of Antarctic Krill in 48 Fishing Areas Based on Fishery Data

根据我国2010—2019年南极磷虾(Euphausia superba)捕捞渔船的生产资料,分析了南极海域48渔区南极磷虾渔场的分布特点,采用重心迁移轨迹模型和标准差椭圆(SDE)模型探讨了南极磷虾的渔场变动特征和规律。结果显示,南极磷虾捕捞量主要集中在48.1亚区,占比为70.30%,48.2亚区和48.3亚区的产量相差很小,占比分别为14.28%和15.42%;年间单位捕捞努力量渔获量(CPUE)曲线上升,最小值为2012年,最大值为2019年;月间CPUE先增后降,最小值为1月,最大值为6月。48.1亚区的年间和月间渔场重心均往西南方向移动;48.2亚区年间的渔场重心东移,但移动范围较小,月间规律不强;48.3亚区年间渔场重心南移,月间渔场重心向西北移动。经SDE分析可知,48.1亚区渔场分布范围最广、离散程度最大,48.3亚区渔场方向性最强、向心力最明显。48.1亚区渔场重心主要分布于布兰斯菲尔德海峡,48.2亚区渔场重心分布于南奥克尼群岛东侧,48.3亚区渔场重心分布于南乔治亚群岛东北侧。聚类结果表明,48.1亚区年间渔场重心均较为集中,48.2和48.3亚区除2017年外,其他年间渔场重心较为集中。

Antarctic krill(Euphausia superba) is a vital part of the food web, supporting substantial fishery in the Southern Ocean. Krill represent the world’s largest animal protein pool, rich in lipids,nutritional long-chain polyunsaturated fatty acids, mineral elements, and carotene, with great potential for development. It is of great significance to understand the changes in fishing grounds, as they profoundly affect the krill population. The distribution characteristics of Antarctic krill fishing grounds in 48 areas were analyzed based on the production statistics of Antarctic krill fishing vessels in China from 2010 to 2019. The gravity center migration trajectory model and standard deviational ellipse(SDE) model were used to analyze the trends and characteristics of Antarctic krill fishing grounds. The results showed that the production of Antarctic krill was mainly concentrated in sub-region 48.1, accounting for 70.30% of total production. The yields of the 48.2 and 48.3 sub-regions showed little difference, accounting for 14.28% and 15.42%, respectively. The annual catch per unit effort(CPUE) curve increased over time,with a minimum value in 2012 and a maximum value in 2019. The monthly CPUE first increased and then decreased, with the minimum value in January and the maximum value in June. The annual and monthly gravity center of Antarctic krill in sub-region 48.1 moved southwest. The annual gravity center of Antarctic krill in sub-region 48.2 moved to the east, but the range of movement was small, and the monthly trends were weak. The annual gravity center of Antarctic krill in sub-region 48.3 moved to the south, and the monthly gravity center moved to the northwest. According to SDE analysis, krill fishing grounds in sub-region 48.1 had the widest distribution and the greatest dispersion, with the strongest directivity and the most obvious centripetal force in sub-region 48.3. The center of gravity of the fishing ground was distributed along the Bransfield Strait in sub-region 48.1, east of the South Orkney Islands in sub-region 48.2, and northeast of the South Georgia Islands in sub-region 48.3. Clustering results showed that the annual fishing ground gravity centers were concentrated in sub-region 48.1. The annual fishing ground gravity centers of sub-regions 48.2 and 48.3 were relatively concentrated in all years, except in 2017.