南海北部近海中国枪乌贼分布与海洋环境关系的空间异质研究

Spatial heterogeneity of relationship between distribution of Uroteuthis chinensiSand marine environment in offshore waterSof northern South China Sea

头足类是最具开发潜力的渔业种群之一,然而其资源易受环境变化影响,复杂的交互作用致使二者空间关系呈现非均一性。中国枪乌贼(Uroteuthis chinensis)是南海北部近海重要的经济物种,且在渔业群落结构中占据优势种地位,故正确理解与掌握该物种资源-环境关系的空间特征,有助于该资源的保护与利用。基于南海北部近海2014年夏季的渔业资源调查数据,构建了地理权重回归模型(Geographical weighted regression,GWR),探索该海域中国枪乌贼的资源分布与海洋环境关系的空间特征,阐述主要影响因子。模型评价指标结果表明,GWR的最小赤池信息准则(Akaike Information Criterion,AIC)和校正决定系数(Adjusted R-Squared,)分别为224.81和0.46,均优于传统的全局线性回归模型,因此前者能更真实地反映中国枪乌贼资源-环境关系的空间异质性。整个海域,叶绿素a对资源的影响为正负效应共存,而其余环境变量与资源均为正效应关系。资源分布在广东近海主要受海表盐度、海表温度和叶绿素a影响,后两者分别为粤西和珠江口—粤东海域的首要影响因子,而北部湾则仅受水深显著影响。在主导环境因子影响下,中国枪乌贼资源密度区域分化特征明显,尤其是珠江口—粤东海域与其他海域差异显著。地理权重回归模型可为探索和理解复杂头足类资源与环境关系的局部特征提供有效手段。

CephalopodSare one of the most potienial fishery specieSbut are vulnerable to environment changes,and their complex interactionSlead to the spatial heterogeneity in resource-environment relationship.UroteuthiSchinensiSiSan important economic specieSin the offshore waterSof northern South China Sea,occuping a dominant position in the fishery community structure.Therefore,understanding the spatial characteristicSof the resource-environment relationship iSbeneficial to itSdevelopment,utilization and protection.Based on the fishery resourceSsurvey data in the offshore waterSof northern South China Sea in summer of 2014,we established a geographically weighted regression(GWR)model to explore the spatial characteristics of the relationship between the resource distribution of U.chinensiSand the marine environment in thiSarea,and to reveal the main influencing factors.The resultSof model evaluation indexeSshow that the minimum Akaike information criterion(AIC)and adjusted R-Square()for GWR model were 224.81 and 0.46,respectively,both of which were better than those of the traditional global linear regression model.Thus,the GWR model could more truly reflect the spatial heterogeneity on resource-environment relationship for U.chinensis.The impact of chlorophyll a on resourceSwaSa coexistence of positive and negative effectSin the whole sea,but the other environment variableShad consistent positive effectSon resources.The stock distribution in the coastal waterSof Guangdong waSmainly affected by sea surface salinity,sea surface temperature and chlorophyll a,and the latter two were the primary influencing factorSin western Guangdong and Pearl River Estuary-Eastern Guangdong,respectively,but the Beibu Gulf waSonly significantly affected by water depth.Under the impact of dominant environmental factors,U.chinensiSstock denstiy showed obviouSregional differentiation characteristics,especially those in the Pearl River EstuaryEastern Guangdong significantly different from the other areas.In conclusion,GWR model provideSan effective meanSto explore and understand the local characteristicSof cephalopod resource-environment relationship.