Based on the concentrations and spatial distributions of heavy metals in 404 surface sediments from the Bohai Sea, we evaluated the marine sediment environmental quality indexes, such as heavy metal potential ecological risk, geoaccumulation index. Moreover, the factors that impact on the concentrations of heavy metals in surface sediments were also analyzed. The results showed that the mean concentrations of all eight heavy metals were highest in the Bohai Bay, and were lowest in the Bohai Strait. The potential ecological risks of Cd and Hg elements were high and moderate-high, respectively. The assessment of total potential ecological risk revealed Bohai Sea belongs to moderate potential ecological risk. Only few stations of Cr and Ni exceed the upper limit of toxic threshold, and the others are less than the lower limit of toxic threshold. This implies the occurrence probability of toxic pollution is low. The concentrations and spatial distributions of heavy metals were mainly dominated by grain size effect of surface sediments from the Bohai Sea. However, Cd element which was rich in the Jinzhou Bay and Fuzhou Bay of Liaodong Bay was mainly contributed by human activities. Hg element, supplied by Yellow River possible impacted by human activities, was rich in the Yellow River Delta and Laizhou Bay.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |