基于GAM模型分析夏秋季南奥克尼群岛南极磷虾渔场时空分布及与环境因子之间的关系

摘要

This study presents an analysis of spatiotemporal distribution of the Antarctic krill ( Euphausia superba) fishery in the South Orkney Islands in the austral summer-autumn during 2009-2010 and 2010-2011. The analysis was carried by applying a generalized additive model (GAM) based on data collected from scientific observers of the Chinese Antarctic krill fishery. The relationship between the spatiotemporal distribution of the Antarctic krill fishery and sea surface temperature (SST) and sea state also were analyzed. Results show that the rate of deviance explained about 41. 78 % of the catch per unit effort ( CPUE). The factor that provided the largest contribution was the month, and its contribution rate was 15. 53%. A significant difference was found for the distribution pattern on CPUE in different months. The average CPUE values were lowest in January and highest in April. A significant difference also was found in average CPUE values among months. The main fishing ground is concentrated at 60°12'S to 60°30'S, 45°30'W to 47°30'W. The suitable SST range is 0.1 to 1.8℃ ,and the most suitable range of SST is 0. 5 to 1. 5℃. The average CPUE values were remarkably different among sea states and vessels. Results of stepwise GAM show the relative importance of the six variables affecting CPUE of the Antarctic krill fishery in the South Orkney Islands. This relationship can be described in the order; month, vessel, longitude, SST, latitude, and sea state.%基于中国南极磷虾渔业科学观察员收集的数据,利用广义可加模型(GAM),对2009 -2010年渔季和2010-2011年渔季夏秋季南奥克尼群岛周边水域南极磷虾渔场时空分布及其与表温和海况之间的关系进行了研究.结果表明,GAM模型对单位捕捞努力量渔获量(CPUE)总偏差解释率为41.78％,其中贡献最大的为月份,贡献率为15.53％；奥克尼群岛水域CPUE分布模式有着明显的月份差异.1月份平均CPUE值最低,而4月份平均CPUE值最高,各月份平均CPUE存在显著性差异.渔场主要集中在60°12′-60°30′S,45°30′-47°30′W.南极磷虾作业渔场的适宜海水表温范围为0.1-1.8℃,最适表温范围为0.5-1.5℃.各海况等级间及不同渔船的平均CPUE均存在显著性差异.逐步GAM模型分析结果表明,影响CPUE的因子按重要性从大到小依次为月份、渔船、经度、海表温度、纬度和海况.