黄海南部和东海小黄鱼资源分布差异性研究

根据2006年6月～2007年4月黄海南部和东海底拖网监测调查资料,比较分析了2个海域小黄鱼资源密度指数(CPUE)分布、环境因子特征、CPUE与环境因子相关关系的差异.研究结果表明,黄海南部和东海小黄鱼资源密度指数分布除了秋季分布有显著差异之外(t′_((33))=2.69,P=0.011),其余季节分布均无显著差异(春季:t′_((43))=1.68,P=0.104;夏季:t′_((60))=0.31,P=0.756 7;冬季:t′_((43))=1.74,P=0.089);夏季的底层盐度分布和水深分布没有明显差异,在其他季节,黄海南部和东海的底层水温、底层盐度和水深分布等环境特征的差异明显,均达到极显著(P<0.01)或显著(P<0.05)水平;资源密度与环境因子回归分析和AIC模型选择中,2个海域夏季的小黄鱼资源密度受到有显著性影响的环境因子数最多,而冬季受到有显著性影响的环境因子最少.综合推断,黄海南部和东海小黄鱼具有不同空间分布特征和环境分布特征,2个海域的小黄鱼分属于不同种群,但在2个海域交界处有混栖种群.

Analysis of the Distribution Difference of Small Yellow Croaker Between the Southern Yellow Sea and the East China Sea

Based on the data collected from bottom trawl surveys conducted in the East China Sea (ECS) and the southern Yellow Sea (SYC) in June 2006 to April 2007, regional difference of CPUE for small yellow croaker, characteristics of environmental factors in its distribution areas and their relationship between the SYS and ECS were analyzed. The results indicated that there were no significant difference in stock-density index between the SYS and ECS in all seasons except autumn (spring: t′_((43))=1.68,P=0.104;summer: t′_((60))=0.31,P=0.756 7;autumn: t′_((33))=2.69,P=0.011;and winter: t′_((43))=1.74,P=0.089). There were no significant regional difference in bottom salinity and depth of distribution areas between the SYS and ECS in summer, while there were significant regional differences in bottom temperature, salinity and depth between the SYS and ECS in spring, autumn and winter. The relationship between environmental factors and CPUE for small yellow croaker was fitted using multiple linear regression analysis, and the influence factors were screened based on Akaike Information Criterion (AIC). The number of environmental factors which influenced the CPUE of small yellow croaker significantly was most in summer, while it was least in winter. It is suggested that small yellow croaker in the SYS and ECS might belong to two different populations, and there was a mixed population in their adjacent water area.