Figure 1

Location map of the Pearl River estuary and sampling stations for the three cruises during 2015–2016. The solid circles denote the sampling stations. PRE, HM, JM, HQM, HeM, MDM and HMH represent the Pearl River estuary, Humen, Jiaomen, Hongqimen, Hengmen, Maodaomen and Huangmaohai, respectively. The inset at the upper right is the location map, which was plotted using Surfer 11 (http://www.goldensoftware.com/products/surfer).