基于Tweedie-GAM探究浙江南部近海蓝圆鲹资源分布及与环境因子的关系

Distribution of Japanese Scad (Decapterus maruadsi) and Its Relationship with Environmental Factors in the Coast Waters of Southern Zhejiang Based on the Tweedie-GAM

本研究根据2015―2020年浙江南部近海水域渔业资源数据,利用Tweedie-GAM研究了春季、夏季、秋季3个季节蓝圆鲹(Decapterus maruadsi)的分布特征及其与海洋环境因子之间的关系。结果显示,蓝圆鲹在不同季节的空间分布存在显著差异,在春季主要集中在沿岸水域,在夏季主要集中在浙江南部近海的南、北两侧,呈现“两边高、中间低”的分布格局,秋季主要集中在研究海域的向海一侧水域。蓝圆鲹在不同季节的关键环境因子存在一定差异。春季,在19.5~25.0℃范围内,资源密度随海水温度的升高呈现先增加后减小的趋势,在22.7℃达到峰值。夏季,分别在海水温度28.0℃和30.3℃取得高峰值和低值,同时,盐度为32.3时资源密度达到最大值。秋季,资源密度随着盐度的增加呈先减小后增加的趋势,在盐度29.8处取得最小值;资源密度和水深之间存在非线性关系,总体呈先增加后基本稳定的趋势。本研究揭示了蓝圆鲹的时空分布特征及与环境因子之间的关系,为浙江南部近海蓝圆鲹的养护管理与可持续利用提供了科学依据。

This study used Tweedie-GAM to evaluate the distribution characteristics of Japanese scad(Decapterus maruadsi)in spring,summer,and autumn(from 2015 to 2020)and its relationship with marine environmental factors.The fishery resources data from the southern Zhejiang coastal waters were combined with the hydrological environment survey data collected simultaneously.The results showed significant differences in the Japanese scad spatial distribution in different seasons.Japanese scad is mainly concentrated in the nearshore waters in spring and concentrated primarily on the south and north regions of the Zhejiang southern waters in summer,showing a"high on both sides,low in the middle"pattern.The distribution pattern in autumn is opposite to that in spring,wherein the Japanese scad mainly concentrated in open waters.There are some differences in the key influencing factors of Japanese scad in different seasons.In spring,with a range of 19.5~25.0℃,the resource density firstly showed an increasing trend and then decreased with the rise in water temperature,peaking at 22.7℃.During summer,the water temperature reached 28.0~30.3℃,and the resource density showed the maximum value when the salinity was 32.3.In autumn,the resource density showed a decreasing trend and later increased with the increment in the water salinity,with a minimum value of 29.8.The relationship between resource density and water depth remained stable,showing a multi-wavy nonlinear relationship,with an overall increasing trend and later stable pattern.This study revealed the relationship between the Japanese scad's temporal and spatial distribution characteristics and environmental factors.It provides a research reference for the conservation,management,and sustainable utilization of Japanese scad in the coastal waters of southern Zhejiang.