Levels and assessment of organotin contamination at Futian Mangrove Wetland in Shenzhen, China

Abstract The concentrations of organotins (OTs) were measured in the surface sediments, mollusks and mudskippers at Futian Mangrove Wetland in Shenzhen, China, an ecologically important wetland that serves as a wintering ground and a stop-over point for migrating birds. The average concentrations of tributyltin (TBT), dibutyltin (DBT), triphenyltin (TPhT) and diphenyltin (DPhT) were 2.42, 9.11, 1.10 and 13.99 ng Sn⋅g −1 (dry weight, dw) in sediments respectively, 1.19, 5.19, 14.41 and 6.11 ng Sn⋅g −1  dw in organisms respectively. Contamination by OTs in the wetland was considered low and concentrations appeared to be declining; this decline presumably comes on the heels of China adopting in 2011, the International Convention on the Control of Harmful Anti-fouling Systems on Ships (AFS convention). However, the biota-sediment accumulation factor of TPhT was relatively high in mollusks and mudskippers. The potential ecotoxicological risk of OTs contamination to the benthic biota and those organisms at higher trophic levels, especially endangered waterfowl inhabiting wetlands, should be of concern. Further, the present study confirmed the accuracy, high stability and time-saving procedure in determination of TBT, DBT, TPhT and DPhT in sediment and organisms through the use of a high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), which may potentially be useful to a wider application in environmental monitoring with limitations of the analytical method for analysis of monobutyltin (MBT) and monophenyltin (MPhT).