Matrix bound phosphine in sediments of the Changjiang Estuary and its adjacent shelf areas Jian-Bing Li a, b , Gui-Ling Zhang a, * , Jing Zhang c , Zhuo-Yi Zhu c , Jing-Ling Ren a , Su-Mei Liu a a Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education of the People’s Republic of China, Department of Marine Chemistry, College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, China b Qingdao Supervision and Testing Center of Product Quality,173 Shenzhen Road, Laoshan District, Qingdao 266061, China c State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 Zhongshan Road North, Shanghai 200062, China article info Article history: Received 10 October 2009 Accepted 7 September 2010 Available online 7 October 2010 Keywords: phosphorus matrix bound phosphine (MBP) sediments Changjiang estuary East China sea abstract Matrix bound phosphine (MBP) is commonly considered an important phosphorus form in the natural environment. This paper presents an investigation of the spatial distribution of MBP and its relationship with the environmental factors in the Changjiang Estuary and its adjacent shelf areas (29.5e32  N, 122 e124  E). A total of 32 surface sediment samples were collected from April 24 to 30, 2008. MBP was detected in all samples from the Changjiang Estuary and its adjacent shelf surface sediments (0.1 e29.7 ng kg 1 ). The concentration of MBP decreased from the Changjiang Estuary to the East China Sea shelf. Environmental factors such as organic matter, type of sediments, and redox conditions were found to affect the concentration and distribution of MBP in the marine sediments. Although the MBP levels were low in the marine sediments, the marine biogeochemical cycles of MBP in sediments were established and the information presented here will contribute to the understanding of the biogeo- chemical cycle of phosphorus. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Phosphorus is a key nutrient in marine biogeochemistry. Studies of the phosphorus cycle have been an important part of global biogeochemical processes (Ruttenberg et al., 2003). Sediment is a key link to the phosphorus cycle in the environment (Watanabe et al., 1998) and different phosphorus species in sediments have been studied (Jensen et al., 1998). Phosphorus can exist in different valences from 3 to þ5 in different environments. However, studies of phosphorus have focused on phosphorus species of þ5 valences. Compared with reduced forms (e.g., CH 4 ,N 2 O, and AVS) of other biogenic elements (C, N, and S), few studies have been carried out on the reduced phosphorus species due to the restriction of analytical techniques. Matrix bound phosphine (MBP) is an operational definition for the phosphine released from sediments due to reaction with sulfuric acid in anaerobic environments. It generally is comprised of adsorbed phosphine in the matrix, metalephosphine complexes, and solid phosphides. MBP has been proven to exist in terrestrial and freshwater ecosystems, for example in river sediments (Gassmann and Schorn, 1993; Feng et al., 2008b), soil (Eismann et al., 1997; Han et al., 2000), sludge in wastewater treatment plants (Dévai et al., 1999; Roels et al., 2005), and lake sediments (Liu et al., 1999; Niu et al., 2004; Geng et al., 2005). It can be hydrolyzed in biological aquatic media to form free phosphine gas. However, there are only a few studies available on MBP in marine environments (Gassmann, 1994; Yu and Song, 2003; Feng et al., 2008a). Phosphorus is often regarded as the ‘ultimate’ limiting nutrient over a long time scale (Cappellen and Ingall, 1996; Tyrrell, 1999). Various species of phosphorus in the surface layer of sediments are important sources of phosphorus in the overlying water (Caraco et al., 1989). Estuarine sediments are an important source and sink of all kinds of nutrients. The forms, distributions, and contents of nutrients can directly affect their marine biogeochemical cycles. The Changjiang Estuary is a typical transitional zone for interaction between land and ocean. It is highly eutrophic and harmful algal blooms frequently happen in this area (Zhou et al., 2008). Hence studies of phosphorus species in sediments will be helpful for us to understand phosphorus cycles in estuaries. In this study we present data of MBP in the surface sediments of the Changjiang Estuary and its adjacent shelf area. The purposes * Corresponding author. E-mail addresses: jblee0787@163.com (J.-B. Li), guilingzhang@ouc.edu.cn (G.-L. Zhang), jzhang@sklec.ecnu.edu.cn (J. Zhang), zyzhu@sklec.ecnu.edu.cn (Z.-Y. Zhu), renjingl@ouc.edu.cn (J.-L. Ren), sumeiliu@ouc.edu.cn (S.-M. Liu). Contents lists available at ScienceDirect Estuarine, Coastal and Shelf Science journal homepage: www.elsevier.com/locate/ecss 0272-7714/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.ecss.2010.09.001 Estuarine, Coastal and Shelf Science 90 (2010) 206e211