黄海大头鳕0龄幼体分布及其与环境因子的关系

摘要

Pacific cod Gadus macrocephalus is distributed around the rim of the North Pacific Ocean, and it’s con-sidered as an ecologically important species. Studies on the biological characteristics and distribution patterns of juvenile Pacific cod would be helpful to understand cod population dynamics. Based on the data collected during the fishery resources surveys carried out in June, August, October and December 2016, the growth of the age 0 group Pacific cod in the Yellow Sea was studied, and the generalized additive model (GAM) was used to analyze the distribution characteristics and their relationship with environmental factors of the age 0 group Pacific cod. The results showed that the age 0 Pacific cod was allometric. Growth rate of the body weight was not equal to the body length, and the weight gain was faster. Allometric factor b was 3.3161. The age 0 group Pacific cods in the Yellow Sea were distributed in the waters in bottom salinity range of 31.7 to 33.3, in bottom water temperature range from 6.6 to 12.1 °C and in depth range of 35.8 to 87.2 m. The favorite sediment in the nursery habitats was fine silty sand and soft clay mud. The seasonal variation in the distribution pattern of the age 0 group Pacific cod was syn-chronized with the seasonal variation of the Yellow Sea cold water mass. The environmental factors which had sig-nificant effects on the ecological density of the cod juvenile were in the order of bottom water temperature, sedi-ment and bottom salinity,while the depth had no significant influence on the juvenile density.%大头鳕是广泛分布于太平洋北部沿岸海域的重要经济和生态种,研究其幼体的生物学特性和分布有助于了解大头鳕的种群动态.本实验根据2016年6月、8月、10月、12月在黄海进行的渔业资源和环境调查数据,研究了黄海大头鳕种群幼体的生长规律;并运用广义可加模型(GAM)方法,分析了该海域大头鳕幼体分布及其与环境因子的关系.结果显示,黄海大头鳕幼体为正异速增长,体质量增长较快,b值为3.316 1.黄海大头鳕0龄幼体主要在底层盐度31.7～33.3、底层水温6.6～12.1 °C、深度35.8～87.2 m、底质为细粉砂或黏土质软泥底质的海域中生活.研究表明,大头鳕幼体分布的季节变化与黄海冷水团的季节演变过程具有同步性.对大头鳕幼体密度有显著影响的环境因子依次为底层水温、底质、底层盐度,而深度对大头鳕幼体密度的影响不显著.