Benthic foraminifera and its response to heavy metal pollution: A case study from Liaodong Bay, China

Benthic foraminifera can be used as an environmental bioindicator, especially in the polluted environment where their sensitivity to pollutants may be expressed by a modification in the assemblage. Based on the quantitative and qualitative analysis of 189 surface sediment samples in Liaodong Bay, 76 benthic foraminifera species which belong to 40 genera were recognized. Q-mode factor analysis was made for the 32 benthic foraminifera species, and three assemblages are recognized: Ammonia aomoriensis- Cribroelphidium magellanicumProtelphidium tuberculatum; Textularia foliacea- Polskiammina asiatica; and Rotalidium annectens- Buccella frigida. To study the effects of heavy metal elements on benthic foraminifera fauna, seven heavy metals elements have been analyzed in all the surface sediment samples, the results show that the heavy metal elements in Liaodong Bay are mainly distributed in Jinzhou Port, and that the overall characteristics are high in northwest and low in southeast. The distribution of foraminifera and heavy metals elements reveals that there is a significant correlation between them. Cribroelphidium magellanicum and Protelphidium tuberculatum have maintained a high level in heavy metal enrichment areas, and may be used as an indicator of heavy metal contamination along the coast of Liaodong Bay.