and benthic organism samples (gastropod and crabs) were collected. Each sediment sample was mixed with 5 sub-samples collected from each sampling plot, while each gastropod sample consisted of 8–10 animals and each crab sample consisted of 3–5 animals collected from the same sampling plot. The most common crabs including Parasesarma plicata, Uca arcuata and Perisesarma bidens were collected in all the studied areas. Chiromantes dehaani was only collected in Changle MNR. Dense astrologer, Metaplax longipes and Helice latimera were only captured in Hainan Dongzhaigang MNR. Snail samples of Littoraria melanostoma, Cerithidea ornate and Certhidea microtera were collected in the Quanzhou and Zhanjiang MNRs.