基于碳氮稳定同位素技术的小清河口邻近海域底栖食物网结构研究

Benthic food web structure of Xiaoqing River Estuary adjacent sea area revealed by carbon and nitrogen stable isotope analysis

为了掌握小清河口邻近海域底栖食物网结构特征,于2020年10月在小清河口邻近海域采集沉积物有机质、悬浮颗粒有机物、浮游动物和浮游植物4种潜在食源及35种生物样本,应用碳氮稳定同位素技术以及贝叶斯混合模型(MixSIAR)分析了小清河口邻近海域底栖食物网结构和营养关系。结果显示,潜在食源的δ^(13)C值范围为−25.56‰~−17.91‰,δ^(15)N值范围为2.43‰~10.33‰;底栖生物的δ^(13)C值范围为−23.48‰~−18.31‰,δ^(15)N值范围为8.79‰~18.01‰;底栖生物营养级范围为1.65(凸壳肌蛤)~3.54(中华栉孔虾虎鱼)。营养关系分析表明,小清河口邻近海域主要存在两条能量传递途径,一是以浮游生物为主要能量来源的浮游食物链,其中双壳类(除短竹蛏)、小型虾类和多毛类等为主要初级消费者;二是以沉积物有机质为主要能量来源的底层食物链,短竹蛏和腹足类为主要初级消费者。整体而言,小清河口邻近海域底栖生物类群间存在一定程度的生态位重叠,竞争较为激烈。

To examine the benthos food web structure in the Xiaoqing River Estuary adjacent sea area,four potential food sources,including sediment organic matter(SOM),suspended particulate organic matter(POM),zooplankton and phytoplankton,and 35 aquatic organisms are collected in October 2020.Carbon and nitrogen stable isotope technique and Bayesian mixing model(MixSIAR)are used to analyze the food web structure and the trophic relationship of benthos.The results show that the δ^(13)C and δ^(15)N values of potential food sources varies from−25.56‰to−17.91‰and 2.43‰to 10.33‰,respectively.Moreover,the δ^(13)C and δ^(15)N values of benthos varies from−23.48‰to−18.31‰and 8.79‰to 18.01‰,respectively.The trophic levels of the main consumers rang from 1.65(Arcuatula senhousia)to 3.54(Ctenotrypauchen chinensis).Trophic relationship analysis showes that there are two main energy transfer pathways in the Xiaoqing River Estuary adjacent sea area.One is the planktonic food chain with plankton as the major energy source,in which bivalves(except Solen brevissimus),small shrimps,and polychaetes are the main primary consumers.The other is the benthic food chain with SOM as the major energy source,in which Solen brevissimus and gastropods are the main primary consumers.On the whole,there is a certain degree of niche overlap and fierce competition among species in the Xiaoqing River Estuary adjacent sea area.