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海洋牧场是一种新的可持续的生产方式,对中国海洋经济的转型具有重要作用.本文根据海底构筑物的密集程度与投放时间把海州湾海洋牧场划分为3个区(外侧区、内测区、中心区),对表层沉积物的温度(T)、酸碱度(p H)、氧化还原电位(Eh)、表面积平均粒径(D[3,2])、总有机碳(TOC)这5种地球化学指标进行原位调查,采用改进的BCR方法对重金属Cr、Cu、Ni、Zn、Pb、Cd进行连续提取.结果表明,沉积物Eh的横向分布受到了海底构筑物的影响,TOC在11.7~13.5 g·kg-1之间,与p H呈显著负相关;Cu、Zn、Ni、Cr以原生相为主要赋存形态,Pb、Cd以次生相的铁锰氧化物结合态(F2)为主要赋存形态,并受Eh控制;相关性及聚类分析表明,Cr、Cu、Ni、Zn为天然源,Cd、Pb存在明显的人为来源;Cr、Ni、Cu、Zn、Pb、Cd的可交换及碳酸盐结合态(F1)与TOC显著相关,Cr、Ni、Cu、Zn、Pb、Cd铁锰氧化物结合态(F2)、Cr、Ni、Cu、Zn的残渣态(F4)都与沉积物粒度显著相关,不同形态的Cd受多环境因子控制;海洋牧场中心区和外侧区沉积物中重金属总量、次生相含量均较内侧区和对照区要低.由于海底构筑物和水动力学的差异性,海洋牧场内侧区细颗粒与有机质对沉积物重金属Cr、Ni、Cu、Zn次生相的富集、吸附作用要大于颗粒再悬浮的释放作用,而在中心区、外侧区细颗粒和有机质影响较小;沉积物富集系数显示Cd出现了富集现象.
Marine pasture is a new and sustainable mode of production and plays an important role in the transformation of China’s marine economy.Based on the concentration and deployment time of marine structures, this paper divided Haizhou Bay marine pastures into three zones (outer zone, (T), pH (p H), oxidation and reduction potential (Eh), surface area average particle size (D [3,2]) and total organic carbon (TOC) The results showed that the horizontal distribution of sediment Eh was affected by the seafloor structure, and the TOC value was in the range of 11.7 ~ 13.5 g · kg-1, and negatively correlated with p H. The primary phases Cu, Zn, Ni and Cr were dominantly formed and the secondary phases of Pb and Cd were iron-manganese oxide-bound ) Were the dominant species and controlled by Eh. Correlation and cluster analysis showed that Cr, Cu, Ni and Zn were natural sources and obvious sources of Cd and Pb were anthropogenic sources. Cr, Ni, Cu, Zn, Pb, The exchangeable and carbonate bound states of Cd (F1) were significantly correlated with TOC, and the contents of Cr, Ni, Cu, Zn, Pb, Cd Fe-Mn oxide bound species The residual state of Zn (F4) was significantly correlated with the grain size of sediments. Cd in different forms was controlled by multiple environmental factors. The contents of total heavy metals and secondary phases in the sediments of central and outer areas of marine pastures were significantly higher than those in the inner and the control areas Was lower than that of the control group due to the difference of seafloor structure and hydrodynamics.The enrichment and adsorption of fine particles and organic matter on the secondary phases of Cr, Ni, Cu and Zn in the sediments in the inner part of the marine pasture were greater than that of the particles resuspended , While the influence of fine particles and organic matter in the outer area on the central area and the outer area is small. The enrichment coefficient of sediments shows that Cd is enriched.