山东近海枪乌贼类资源丰度的时空变动及其与环境因子的关系

Spatial-Temporal Variations of Loligo Squids Abundances in Shandong Coastal Waters and Associating Environmental Factors

枪乌贼类(主要是日本枪乌贼(Loligo japonica)和火枪乌贼(Loligo beka))是山东近海头足类中的重要经济种,它寿命短、生长快,其资源变动极易受到外界环境因素的影响。本研究根据2016—2017年山东近海渔业资源底拖网调查数据,利用广义加性模型(Generalized additive model,GAM)分析枪乌贼类资源丰度的时空分布特征及其与环境因子的关系。研究表明,枪乌贼类的资源丰度秋季最高、春季最低,且主要分布在山东半岛南部的海州湾产卵场附近,呈现出显著的时空变化特征。GAM分析表明,除了季节因素外,海水深度、表层温度和表层盐度对枪乌贼类的资源丰度具有明显影响;在海水表层温度16℃、表层盐度31.2~32.5和水深40 m以内的水域,枪乌贼类的资源丰度较大。本文研究结果可为研究枪乌贼类的资源变动和可持续利用提供科学依据。

Loligo squids(Loligo spp.,mainly L.japonica and L.beka)are the most commercially important species among cephalopods in Shandong coastal waters recently.Loligo squids can be regarded as typical r-strategy species due to their short lifespan and rapid growth rate.Their landings fluctuate largely and associate closely with environmental factors.In this study,we explored the spatial-temporal variations in the abundance of loligo squids based on four seasonal bottom trawl surveys from 2016 to 2017 in Shandong coastal waters,and examined the impacts of environmental factors using generalized additive models(GAM).Results showed that the abundance of loligo squids exhibited distinct seasonal and spatial variation patterns with the highest abundance being documented in the fall(October)and the lowest in the spring(May).High distribution was occurred in the south of Shandong Peninsula,particularly in the Haizhou Bay where is the primary spawning ground of loligo squids in the Yellow Sea.GAM analysis indicated that the abundance was affected by SST,water depth,and salinity besides seasons.The abundance of loligo squids increased with SST(within 5~16℃,mainly 16℃)and with salinity(>31.2),and was higher at depths shallower than 40 m.The present research has important implications for explaining spatial-temporal variations and sustainable utilization of cephalopods in the Yellow Sea and Bohai Sea.