东海外海海域生物体内总汞蓄积差异性研究

Accumulation Differences of Total Mercury in Organisms in the Offshore Area of East China Sea

为了解东海外海海域不同种类生物体内总汞的蓄积差异性,使用直接测汞仪测定在东海外海海域捕捞的不同种类生物可食组织中的总汞含量,从不同生物的食性、食物链层级、栖息水层等方面对其总汞含量差异性进行了初步比较分析。研究发现,东海外海海域22个品种共计104个样本中,总汞含量范围在0-0.557 mg·kg^-1之间,平均值为0.103 mg·kg^-1,均低于GB 2762 2017标准限量值。不同食性生物体内的汞含量的差异关系为:底栖动物食性鱼类(0.153 mg·kg^-1)>浮游生物食性鱼类(0.093 mg·kg^-1)>鱼食性鱼类(0.084 mg·kg^-1);汞可通过海洋食物链产生生物放大作用,处于食物链上层营养级的物种通过捕食行为使汞在食物链传递过程中产生一定的富集和放大效应;不同栖息水层的生物体总汞含量均值分布趋势为:泥沙底层(0.122 mg·kg^-1)>底层(0.067 mg·kg^-1)>中下层(0.060 mg·kg^-1)>中上层(0.041 mg·kg^-1),说明鱼体内的汞含量与其栖息水层密切相关,尤其是生活在泥沙底层或底层和中下层的生物体内的汞含量高于生活在中上层的生物,如短鳍红娘鱼(Lepidotrigla microptera,0.178 mg·kg^-1)汞含量平均值高于竹荚鱼(Trachurus japonicus,0.042 mg·kg^-1)。结果表明,东海外海海域生物体内总汞蓄积含量差异性与生物的种类、生活习性及其所处食物链结构和长度等因素有关。

In this paper,total mercury content in different types of organisms was measured by direct mercury meter to study bioacummulation of mecury in East China Sea.The differences of total mercury content in organisms were compared and analyzed in terms of feeding habit,food chain levels and perch water layers.The result showed that total mercury content of the 104 samples from 22 species in the offshore area of East China Sea ranged from 0 to 0.557 mg·kg^-1,with an average of 0.103 mg·kg^-1,no samples exceeded the maximum content level set in GB2762 2017.The analysis of average mercury content in different levels of food chain showed that:benthic predators(0.153 mg·kg^-1)>zooplanktivors(0.093 mg·kg^-1)>piscivores(0.084 mg·kg^-1);a magnifying effect for mercury existed in the marine food chain,and mercury enrichment and amplification happened in the upper vegetative level species;the mercury content in the fish was closely related to its habitat layer:the mercury content in species living in the sediment-bottom or bottom and lower-middle layers was higher than that of upper-middle living organisms,for example,the average mercury content of Lepidotrigla microptera(0.178 mg·kg^-1)was higher than Trachurus japonicus(0.042 mg·kg^-1).The mean total mercury content of organisms in different habitats layer showed the following distribution trends:sediment-bottom(0.122 mg·kg^-1)>bottom(0.067 mg·kg^-1)>lower-middle(0.060 mg·kg^-1)>upper-middle(0.041 mg·kg^-1).The results show that the difference of total mercury accumulation in organisms in the East China Sea is related to species and habits of organisms.