秘鲁外海茎柔鱼(Dosidicus gigas)渔场的时空分布与海表温度的关系分析

Relationship between spatial and temporal distribution of jumbo flying squid Dosidicus gigas off Peru and sea surface temperature

茎柔鱼是大洋经济头足类,广泛分布秘鲁外海。深入了解茎柔鱼渔场的时空分布与环境变化的关系可为茎柔鱼资源的可持续利用及管理提供科学根据。本文根据中国远洋渔业数据中心提供的2006—2015年东南太平洋9—12月8°~20°S,75°~95°W海域的茎柔鱼捕捞数据,计算茎柔鱼渔场年际经度和纬度重心位置变动,量化渔场重心的时空变化。此外对渔场重心进行聚类分析,通过捕捞努力量和SST的频率分布关系分析茎柔鱼渔场内SST变化对渔场重心位置的影响。结合水温因子进一步研究茎柔鱼渔场重心对拉尼娜事件和厄尔尼诺事件的响应规律。结果发现,茎柔鱼渔场重心月份和年际变化显著,聚类分析结果将各年渔场重心分为3类。各月份捕捞努力量在经纬度和SST上的频次分布具有明显差异。相对于厄尔尼诺年份(2015年),拉尼娜年份(2007年)茎柔鱼渔场内SST较低,最适宜温度锋面向西北方向偏移,导致该年茎柔鱼渔场重心相对于2015年偏西北。研究表明秘鲁外海茎柔鱼渔场的时空分布变化与大尺度气候事件调控的水温变化具有紧密关联。

Jumbo flying squid Dosidicus gigas is a pelagic and economically important squid species widely distributed off Peru.The purposes of this study were to understand the relationship between spatio-temporal fishing grounds of D.gigas and environmental conditions,and to provide a scientific basis for the sustainable utilization and management of D.gigas resources.Based on the fisheries data of D.gigas in the southeast Pacific Ocean off Peru from September to December,2006 thorough 2015 provided by National Data Center of Distant-water Fisheries of China,in this study,we determined the position of longitudinal and latitudinal gravity center of fishing ground,and quantified the temporal and spatial changes of fishing ground.In addition,the cluster analysis on the fishing ground gravity centers was performed.The relationship between fishing effort and sea surface temperature(SST)was examined based on frequency distribution analysis and the influence of SST on the changes of fishing ground gravity centers was further evaluated.The responses of fishing ground gravity centers to the La Nina and El Nino events were finally explored.Significant monthly and interannual variations were found in the longitudinal and latitudinal gravity centers of the fishing ground.Cluster analysis divided the fishing ground gravity centers into three categories.The fishing effort distribution in the longitude,latitude and SST showed a large difference from month to month.Compared with the El Nino year(2015),the SST on the fishing ground in the La Nina year(2007)was lower,leading to the northwestward shift of the most preferred temperature front for D.gigas.Therefore,the gravity centers of fishing ground in 2007 moved northwestward.The results indicated that spatio-temporal distribution of D.gigas was closely related to large-scale climate variability-induced SST change.