title: Spatiotemporal Trends of Heavy Metals in Indo-Pacific Humpback Dolphins (Sousa chinensis) from the Western Pearl River Estuary, China.
abstract: We assessed the spatiotemporal trends of the concentrations of 11 heavy metals (HMs) in the liver and kidney of Indo-Pacific humpback dolphins (Sousa chinensis) from western Pearl River Estuary (PRE) during 2004-2015. The hepatic levels of Cr, As, and Cu in these dolphins were among the highest reported for cetaceans globally, and the levels of Zn, Cu, and Hg were sufficiently high to cause toxicological effects in some of the animals. Between same age-sex groups, dolphins from Lingdingyang were significantly more contaminated with Hg, Se, and V than those from the West-four region, while the opposite was true for Cd. Generalized additive mixed models showed that most metals had significant but dissimilar temporal trends over a 10-year period. The concentrations of Cu and Zn increased significantly in recent years, corresponding to the high input of these metals in the region. Body-length-adjusted Cd levels peaked in 2012, accompanied by the highest annual number of dolphin stranding events. In contrast to the significant decrease in HM levels in the dolphins in Hong Kong waters (the eastern reaches of the PRE), the elevated metal exposure in the western PRE raises serious concerns.
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Duan
authors.identifier: 0000-0002-0236-6837
authors.initials: D
authors.lastname: Gui
authors.affiliation: Department of Biology, University of Texas at Tyler , Tyler, Texas 75799, United States.
authors.forename: Ri-Qing
authors.initials: RQ
authors.lastname: Yu
authors.affiliation: The Swire Institute of Marine Sciences, School of Biological Sciences, The University of Hong Kong , Cape d'Aguilar, Shek O, Hong Kong.
authors.forename: Leszek
authors.initials: L
authors.lastname: Karczmarski
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Ding
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Haifei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.affiliation: South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University , Guangzhou, 510275, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000818:Animals; D002681:China; D004289:Dolphins; D063366:Estuaries; D019216:Metals, Heavy / Q000633:toxicity*; D045483:Rivers
chemical_list: D019216:Metals, Heavy