北太平洋鱿鱼渔场叶绿素a分布特点及其与渔场的关系

Distributional characteristics of chlorophyll a and relation to the fishing ground in the squid fishing ground of the northern Pacific Ocean

根据2001年6～8月对位于39°～43°N,152°E～171°W的北太平洋鱿鱼渔场进行的水温、盐度、叶绿素a、浮游植物和鱿鱼捕捞等的调查结果,主要分析北太平洋鱿鱼渔场表层叶绿素a分布特点及其与环境因子、中心渔场的关系.分析结果表明,调查区表层叶绿素a含量变化为0 03～0 32mg/m3,平均为0 13mg/m3,其中中部渔场表层叶绿素a含量值最大,东部渔场次之,西部渔场最低;调查海域表层叶绿素a含量分布与表层温度、盐度存在较好的对应关系,叶绿素a含量高值区对应高温区,冷涡区含量最低,暖涡区含量最高;叶绿素a含量随盐度的增加而增加;在西部、中部、东部渔场,表层叶绿素a含量与浮游植物数量呈正相关关系;表层叶绿素a的分布与鱿鱼中心渔场存在较好的对应关系,中心渔场主要位于0 1mg/m3叶绿素a等值线舌状部分或叶绿素a水平梯度较大处,渔场中心的叶绿素a值大于0 1mg/m3.叶绿素a分布与环境要素及渔场的相关性分析表明叶绿素a可作为鱿鱼渔场分析中的一个重要参考指标.

On the basis of the investigating results of chlorophyll a, water temperature, salinity, phytoplankton and squid fishing in the squid fishing ground(39°～43°N,152°E～171°W) of the northern Pacific Ocean during June to August of 2001, The distributional characteristics of surface chlorophyll a and relation to the environmental factors and squid fishing ground were mainly analyzed. The analyzing results show that the content of surface chlorophyll a in the investigating area is between 0.03 and 0.32 mg/m^(3), mean value is 0.13 mg/m^(3). Among them, the content of surface chlorophyll a in the middle part fishing ground is the biggest, the second is the in the eastern-part and the lowest is in the western-part. There is a good relationship of the distributions of surface chlorophyll a contents with water temperature and salinity in the survey area. The high chlorophyll a content is located in the region with high temperature, the content is the lowest in the cold eddy and the highest in the warm eddy. The chlorophyll a content increases with increasing of salinity. The surface chlorophyll a content has a positive relationship with the phytoplankton in the west, middle and east fishing grounds. The distribution of surface chlorophyll a also exits a better relation with the middle part fishing ground of squid which mainly is located in the tongue part of 0.1 mg/m^(3)of isopleth and the maximum gradient belt. The values of the surface chlorophyll a in the middle part fishing ground were more than 0.1 mg/m^(3). The relative analyses of distributional of chlorophyll a with the environmental factors and fishing ground indicate that it may be as an important reference index in the study of squid. fishing grounds.