摘要
为探究塞内加尔近海渔场的时空分布及其与环境因子的关系,根据2018-2020年我国远洋入渔塞内加尔拖网渔船的渔捞日志数据,运用渔场重心分析及地统计插值方法研究了塞内加尔近海渔场的时空变化,并结合海洋遥感数据[海表温度(SST)及叶绿素a(Chl-a)],利用广义可加模型(GAM)探究了单位捕捞努力量渔获量(CPUE)与时空、环境因子的关系.结果表明:1)2018-2020年塞内加尔近海渔场主要分布于12°00′～16°00′N、16°30′～18°00′W的海域,每年1-6月渔场重心向北部渔场迁移、7-12月渔场重心迁移至南部渔场;2)GAM模型累计偏差解释率为17.8％.年份(Year)、月份(Month)、纬度(Lat)、经度(Lon)和SST对CPUE有显著影响(P＜0.05);3)塞内加尔近海渔场最适SST范围为22～24℃,最适Chl-a浓度范围为2～3 mg·m-3.研究结果可为了解塞内加尔近海渔场资源时空变化规律、指导过洋性远洋渔业科学生产提供参考.
Abstract
To explore the spatiotemporal distribution of offshore fishing grounds in Senegal and its relationship with environmental factors,this study utilized the fishing log data from trawl fishing vessels in the offshore fishing grounds of Senegal from 2018 to 2020,employed fishery center of gravity analysis and geostatistical interpolation methods to investigate the spatiotemporal changes in Senegal's offshore fishing grounds.Additionally,by combining corresponding ocean remote sensing data(sea surface temperature SST,and chlorophyll-a Chl-a),a generalized additive model(GAM)was used to explore the relationship between catch per unit of fishing effort(CPUE)and spatiotemporal and environmental factors.The main conclusions were as follows:1)Temporally,the catch and CPUE in Senegal's offshore fishing grounds from 2018 to 2020 exhibited a trend of initial increase,followed by a decrease,and then a subsequent increase.Spatially,Senegal's offshore fishing grounds were primarily distributed in waters between 12°00′N to 16°00′N and 16°30′W to 18°30′W.The fishing ground center of gravity moved northward from January to June and returned to the southern fishing grounds from July to December,with minimal changes in the longitudinal direction;2)The accumulative deviance explanation of GAM model was 17.8％,with the year(Y)contributing the most at 5.83％,followed by longitude(Lon),month(M),and SST at 4.37％,3.90％,and 2.80％,respectively.Latitude(Lat)and Chl-a had the least contributions at 0.70％and 0.20％,respectively.The F-test indicated that the influences of Y,M,Lat,Lon,and SST on CPUE were significant(P＜0.05),while the influence of Chl-a was not significant(P＞0.05);3)SST was the most influential environmental factor on CPUE,and the optimal SST range was 22-24 ℃,the optimal Chl-a concentration range was 2-3 mg·m-3.The study can provide scientific basis for the understanding of dynamics of offshore fishing grounds in Senegal,assessing and sustainably utilizing fishery resources in the area.
维普
万方数据