Baseline Metal concentrations in selected tissues and main prey species of the annulated sea snake (Hydrophis cyanocinctus) in the Hara Protected Area, northeastern coast of the Persian Gulf, Iran Mohsen Rezaie-Atagholipour a , Alireza Riyahi-Bakhtiari b,⇑ , Mirmasoud Sajjadi a , Chee Kong Yap c , Sanaz Ghaffari b , Zohreh Ebrahimi-Sirizi b , Parviz Ghezellou a a Department of Marine Biology, Faculty of Sciences, University of Hormozgan, P.O. Box 3995, Bandar Abbas, Hormozgan, Iran b Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, P.O. Box 46414-356, Noor, Mazandaran, Iran c Department of Biology, Faculty of Sciences, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia article info Keywords: Metals Annulated Sea Snake Hydrophis cyanocinctus Mudskippers Persian Gulf Iran abstract This study is the first detailed ecotoxicological study of the annulated sea snake, Hydrophis cyanocinctus. Concentrations of lead, cadmium, nickel and vanadium were evaluated in muscle, liver, kidney, skin and blood of the annulated sea snake (H. cyanocinctus) and in the whole bodies of its main prey species (Peri- ophthalmus waltoni and Boleophthalmus dussumieri) in the Hara Protected Area, the Persian Gulf. The mean concentrations of lead and vanadium were highest in the kidney, which identified the kidney as a target organ for metals in sea snakes as it is in other reptilian groups. Mean concentrations of cadmium and nickel were highest in the liver and skin, respectively. Mean cadmium concentrations were signifi- cantly higher in the liver compared to prey species, which indicated that prey items may be a source of cadmium for the annulated sea snake in the study area. Data presented here may be considered as a baseline for further ecotoxicological studies in sea snakes. Ó 2011 Elsevier Ltd. All rights reserved. There are two main arguments regarding the importance of contaminant research on snakes. First, snakes are considered to be an ideal species for monitoring contaminants in wildlife. All snakes are carnivores and are known to accumulate environmental contaminants (Albrecht et al., 2007; Burger et al., 2005, 2006, 2007; Campbell et al., 2005; Hopkins et al., 1999, 2001; Wylie et al., 2009). Most snake species are comparatively sedentary ani- mals and live in a small home range; thus, it is possible to make comparisons between contaminant data from multiple sites (e.g., polluted sites and control sites) in a narrow geographical area (Campbell et al., 2005; Hopkins et al., 1999, 2001). Also, as exper- imental models, many species of the squamata reptiles (snakes and lizards) are more logistically helpful for ecotoxicological studies than turtles and crocodilians (Hopkins, 2000). The second argument is that environmental contaminants are one of the great global threats to reptile populations (Gibbons et al., 2000; Irwin and Irwin, 2006). Nonetheless, in comparison with the other vertebrate groups, reptiles have been studied the least by environmental toxicologists (Hopkins, 2000; Smith et al., 2007). For these reasons, ecotoxicological studies of the various species of snakes are extremely important (Campbell and Camp- bell, 2001). Most contaminant research in snakes has been done in species of the family Colubridae, which is logical because more than two thirds of all snake species belong to this family (Campbell and Campbell, 2001). Sea snakes are the largest group of marine reptiles (Heatwole and Cogger, 1993) that inhabit the tropical and subtropical Indo- Pacific coastal habitats (Heatwole, 1999). Sea snakes have an important role in the food chains of these communities (Voris, 1972). The annulated sea snake (Hydrophis cyanocinctus) is domi- nant among the 10 species of sea snakes that exist in the Persian Gulf (Gasperetti, 1988). The Persian Gulf includes about 800 offshore oil and gas plat- forms, 25 major oil terminals and is an important oil and gas indus- trial region. It has been estimated that 6–8 million barrels of oil were spilled into the Persian Gulf during the Iran/Iraq war (Shepp- ard et al., 2010). Oil pollution is one of the major concerns in the Persian Gulf, and inshore oil residues, tar balls and metal contam- inants greatly impact this environment (Sheppard et al., 2010). All metals measured in the present study (lead, cadmium, nickel and vanadium) are found in crude oil (Neff, 2002). The results of a pre- vious study determined that the concentrations of lead, cadmium and nickel in sediments from the northern (Iranian) coastline of the Persian Gulf were higher than global baseline values (Pourang et al., 2005). 0025-326X/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2011.11.015 ⇑ Corresponding author. Tel.: +98 1226253101; fax: +98 1226253499. E-mail address: riahi@modares.ac.ir (A. Riyahi-Bakhtiari). Marine Pollution Bulletin 64 (2012) 416–421 Contents lists available at SciVerse ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul