湖北地区养殖河蟹(Eriocheir sinensis)组织中微塑料的赋存特征

Characteristics of Microplastics in the Tissues of Cultured River Crabs(Eriocheir sinensis)in Hubei

微塑料在全球淡水中普遍存在。微塑料可经食物链传递、富集,危及水产品质量安全乃至人类健康。目前微塑料研究多集中于海洋生态系统,与人类活动联系最紧密、受人类活动影响最大的淡水生态系统研究还较少。为探究养殖河蟹(Eriocheir sinensis)体内微塑料污染情况,采用化学消解结合拉曼光谱扫描方法对湖北省洪湖市与监利市5个养殖场的河蟹肌肉和肝胰腺组织、底层水、底层沉积物进行检测。结果表明,肌肉组织及底层沉积物中未检出微塑料,3个养殖场的河蟹肝胰腺组织中含有微塑料(平均丰度1.22 g^(-1)),1个养殖场的底层水存在微塑料(0.13 L^(-1))。所有检出微塑料的形状以碎片状为主(74.28%),其余为颗粒状;化学组成有聚苯乙烯(PS)、聚乙烯(PE)、氟化乙烯丙烯共聚物(Teflon FEP)3种;根据颜色分为透明、白色、红色3类。检出微塑料的大小均为100~350μm。河蟹肝胰腺组织与底层水中检出微塑料外观相似,但尺寸不同。研究结果提示底层水污染是养殖河蟹体内微塑料的可能来源。当前湖北河蟹养殖过程中的环境微塑料污染程度较低,河蟹微塑料污染风险安全可控。

Microplastics(MPs)are prevalent in fresh water all over the world.Previous studies have shown that MPs pollution in the freshwater environment of China is particularly severe.Once ingested by aquatic organisms,MPs can be transmitted through the food chain and accumulated in high trophic organisms,which indirectly endangers the quality and safety of aquatic products,and eventually may become a potential threat to human health.However,most of the researches on MPs have been focused on marine ecosystems,and less been conducted for freshwater ecosystems,while freshwater ecosystems are more closely linked to and affected by human activities.In order to investigate the extent of MPs contamination in farmed river crabs(Eriocheir sinensis),the muscle and hepatopancreas tissues of Eriocheir sinensis,bottom water and bottom sediment from five aquafarms in Jianli city and Honghu city,Hubei Province were examined by chemical digestion combined with Raman spectroscopy.The results show that MPs were not detected in the muscle tissue and bottom sediment,but were detected in the hepatopancreas tissue of three aquafarms(mean abundance 1.22 g^(-1)),and in the bottom water of one aquafarm(0.13 L^(-1)).The shape of all detected MPs was mainly fragmented(74.28%)and the rest were granular;the chemical composition was polystyrene(PS),polyethylene(PE),and fluorinated ethylene propylene copolymer(Teflon FEP).All the detected MPs were classified according to color as transparent,white,and red.The sizes of the detected MPs were all in the range of 100~350μm.The appearance of the MPs detected in the hepatopancreas tissues of Eriocheir sinensis crabs was similar to that in the bottom water,but the sizes were different.The appearance characteristics and chemical composition of MPs are closely related to their sources,and physical and chemical characterization can help for the tracing of MPs.The results of this study suggest that bottom water pollution may be a possible source of MPs in Eriocheir sinensis.The current risk of environmental MPs contamination during river crab farming in Hubei is low,and the risk of MPs contamination in Eriocheir sinensis is controllable.