Bioavailability of trace metals in sediments of a recovering freshwater coastal wetland in China's Yellow River Delta, and risk assessment for the macrobenthic community. (December 2017)

• Record Type: Journal Article
• Authors: Yang, Wei; Li, Xiaoxiao; Pei, Jun; Sun, Tao; Shao, Dongdong; Bai, Junhong; Li, Yanxia
• Is Part Of: Chemosphere. Volume 189(2017)
• Page Start: 661
• Page End: 671
• Publication Date: 2017-12
• Subjects: Trace metal speciation -- Macrobenthic communities -- Metal bioavailability -- Freshwater release -- Ecological risk assessment; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.09.103
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: We investigated the speciation of trace metals and their ecological risks to macrobenthic communities in a recovering coastal wetland of China's Yellow River Delta during the freshwater release project. We established 16 sampling sites in three restoration areas and one intertidal reference area, and collected sediments and macrobenthos four times from 2014 to 2015. The instability index for the trace metals showed a moderate risk for Mn and a high risk for Cd. For both Mn and Cd, the carbonate and FeMn-bound fractions appear to contribute mostly to the instability and bioavailability indexes, but for Cd, the exchangeable fraction also have a much higher contribution. The bioavailability index indicated higher bioavailability of trace metals in freshwater restoration areas than that in the intertidal area. The single-factor contamination index indicated that most trace metal concentrations in the macrobenthos were in excess of the national standard. The biota-sediment accumulation factor suggested that the macrobenthos accumulated most As, Cd, and Cu. Redundancy analysis showed clear relationships between the macrobenthos and sediment metal concentrations. Our results will help wetland managers to assess the bioaccumulation risks based on metal speciation, and to improve management of these recovering freshwater wetland ecosystems. Highlights: We assessed the instability and bioavailability of sediments. Mn and Cd showed moderate and high risks and only Cd exhibited high bioaccumulation. As showed a high accumulation risk in despite of its low ISI and BAI values. BSAF and BSAF m values differed greatly for As, Cr, Cd, and Ni. Chironomids may serve as a bioindicator in restoration areas.