黑潮和亲潮生态系统中上层渔获量变动趋势及影响因素分析

Variation trend and influencing factors of catch in mid-pelagic species of Kuroshio and Oyashio ecosystems

西北太平洋是全球最主要的渔业区域之一,局域和区域尺度的环境和气候变化对其中上层渔业资源影响是一个重要科学基础问题。以1950—2014年黑潮和亲潮大海洋生态系中上层暖性、温性以及暖温性鱼种3个类别的渔获量为研究对象,以标准化常态分布值作为渔获量变动趋势的指标,利用广义加性模型(generalized additive model,GAM)分析海表面温度(sea surface temperature,SST)、太平洋年代际震荡(pacific decadal oscillation,PDO)、Nino3.4指数以及SST时空变异对黑潮和亲潮大海洋生态系不同适温性种类渔获量变动的影响。研究发现,1950—2014年间,各类别的渔获量变动趋势基本相同,但是总渔获量的变动趋势不同。GAM模型发现,亲潮大海洋生态系模型的解释率高于黑潮大海洋生态系,影响两个大海洋生态系渔获量趋势变动的关键因子(PDO指数和SST时空变化)存在差异,但是除了亲潮大海洋生态系暖温性鱼种外,影响总渔获量和其他类别渔获量的显著因子都包含了SST。SST上升与黑潮大海洋生态系总渔获量和暖温性鱼种渔获量变动呈正相关,而与亲潮大海洋生态系呈负相关,Nino3.4指数等其他环境因子对各类别渔获量的变动影响趋势相同。研究结果可为环境和气候事件对黑潮和亲潮大海洋生态系中上层渔业资源量变动趋势的影响及其影响机理的探究提供一定依据。

The northwest Pacific is one of the most important fishery regions in the world.The impacts of local and regional-scale environment and climate changes on the mid-pelagic fishery resources are important scientific issues.This study took three types of catches of warm,temperate and warm-temperate fish species in the middle and upper layers of Kuroshio and Oyashio currents from 1950 to 2014 as research object,and standardized normal distribution value was used as an indicator of the trend of catch changes.GAM(generalized additive model)model was used to analyze the sea surface temperature(SST),Pacific decadal oscillation(PDO),Nino3.4 index and SST spatial-temperal compilation,and three types of Kuroshio and Oyashio sea areas.The study found that from 1950 to 2014,the change trend of the catch of each category was basically the same,but the change trend of the total catch was different.GAM model found that the best-fitting combination of variables for the Z value of Kuroshio current’s mid-pelagic fish species was SST+PDO+SVK,and the model deviation interpretation rate was 53.0%,among which SVK had the highest contribution rate 28.0%,followed by SST 14.9%and PDO 10.4%,and for the Z value of Kuroshio current’s mid-pelagic warm fish species was PDO+Nino3.4,for the Z value of Kuroshio current’s mid-pelagic temperate fish species was SST,for the Z value of Kuroshio current’s mid-pelagic warm-temperate fish species was PDO+SST.The best-fitting combination of variables for the Z value of Oyashio current’s mid-pelagic fish species was SST+SVO,among which SST was 44.5%,SVO was 16.9%,and for the Z value of Oyashio current’s mid-pelagic warm fish species was PDO+Nino3.4+SVO,for the Z value of Oyashio current’s mid-pelagic temperate fish species was SST,for the Z value of Oyashio current’s mid-pelagic warm-temperate fish species was PDO+SST+Nino3.4+SVO.The interpretation rate of the Oyashio model was higher than that of the Kuroshio.The key factor affecting the trend of the catch in the two seas was PDO.The difference between the index and SST in time and space changed,but in addition to the warm-temperate fish species in the tide seas,the significant factors affecting the total catch and other types of catches all included SST.The increase in SST was positively correlated with the changes in total catches of Kuroshio waters and the catches of warm-temperate fish species,while it was negatively correlated with the Oyashio waters.Other environmental factors showed the same influence on the changes in other types of catches.The research results can provide a basis for the investigation of economic fish species resources and the mechanism of environmental and climate events in Kuroshio and Oyashio waters.