Geochemical characteristics of phosphorus in surface sediments of two major Chinese mariculture areas: The Laizhou Bay and the coastal waters of the Zhangzi Island

Abstract

a b s t r a c tPhosphorus (P) in surface sediments of the Laizhou Bay (LB) and the coastal waters around the Zhangzi Island (ZI) was analyzed. Six forms of P were separated -exchangeable or loosely sorbed P (Ads-P), aluminum-bound P (Al-P), iron-bound P (Fe-P), authigenic apatite plus CaCO 3 -bound P plus biogenic apatite (Ca-P), detrital apatite plus other inorganic P (De-P) and organic P (OP). The average contents of P in the LB were in the order: De-P > OP > Ca-P > Fe-P > Ads-P > Al-P; in the ZI, the corresponding order was De-P > OP > Fe-P > Ca-P > Ads-P > Al-P. Due to the high nutrient loadings from the surrounding rivers, TP contents in sediments of the LB were higher than in those of the ZI. The potential bio-available P (Ads-P and OP) accounted for 14.7% and 24.2% of TP in sediments of the LB and the ZI, respectively.Ó 2014 Elsevier Ltd. All rights reserved.As an important biogenic element in the ocean, phosphorus (P) directly affects the primary productivity of the ocean and has a significant impact on the marine carbon cycle (Lui and Chen, 2011;Yu et al., 2012); P is also directly related to the global climate and environmental changes (Krom et al., 2004). Hecky and Kilham (1988) pointed out that P might be the element which controlled the global marine biological productivity during a long geologic time scale (>1000 years). As an important reservoir of P in marine environment, sediment not only has a buffering effect on the P content in the overlying water, but also is an important source of P in seawater (Giblin et al., 1997;Zabel et al., 1998). Fisher et al. (1982) reported that sediments provided 28-35% of P needed in the primary productivity of coastal marine ecosystems.Both organic and inorganic forms of P are present in marine sediments. Inorganic forms of P may be adsorbed onto the surfaces of minerals, or be bound to aluminum, iron, or calcium (Föllmi, 1996;Benitez-Nelson, 2000;Łukawska-Matuszewska and Bolałek, 2008;Song, 2010). The binding forms of P in sediments have major influences on transportation, degradation, and the ultimate fate of P in marine ecosystems. Only certain forms of P can be transformed into bio-available ones after being affected by physical, chemical and biological factors, including desorption, dissolution and reduction processes (Song, 2010). After that, the bio-available forms of P are released into the overlying water. These certain forms of P become important factors affecting the trophic status of water or causing eutrophication (Eijsink et al., 2000). Therefore, research on the geochemical forms of P in sediments may help researchers understand the dynamic cycle of P in seawater and sediments, such as migration and transformation between sediments and the overlying water, and subsequent diagenesis and other geochemical processes (Zabel et al., 1998;Eijsink et al., 2000).The Laizhou Bay and the surrounding marine area of the Zhangzi Island (hereafter referred to as the Zhangzi Island for short) are important mariculture zones in China, and they are located in the B...

Geochemical forms and seasonal variations of phosphorus in surface sediments of the East China Sea shelf

“…Among the various types of natural particles, iron hydroxides and oxides have the strongest adsorption capacity for P (Berner, 1973;Zhuang et al, 2014). Fe-P percentages of TP were relatively higher than Ads-P (Fig.…”

“…Sediment is an important indicator of marine environmental changes (Meyers, 2003;Schelske et al, 1988Schelske et al, , 2006Yu et al, 2013). Phosphorus (P), an important biogenic element, plays an important role in the biological productivity in marine environments (Benitez-Nelson, 2000;Song, 2010;Lui and Chen, 2011;Yu et al, 2012;Samadi-Maybodi et al, 2013;Zhuang et al, 2014). Its cycle is markedly affected by processes taking place in the sediments and at the water-sediment interface (Fisher et al, 1982;Ruttenberg and Berner, 1993;Van Raaphorst and Kloosterhuis, 1994;Föllmi, 1996).…”

Distributions, sources and ecological risk assessment of arsenic and mercury in the surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea

“…Analytical methods and results of the total organic carbon (TOC), grain size and moisture content of the samples have been described in our previous publications (Zhuang and Gao, 2013, 2014a, 2014bZhuang et al, 2014). The substance concentrations in the sediments were expressed on the dry weight basis based on the results of moisture content.…”

Geochemistry of phosphorus in sediment cores from Sishili Bay, China

“…De-P is usually found to be concentrated in sand fraction, while other P fractions concentrated in clay and silt fractions (Yu et al, 2011(Yu et al, , 2013Meng et al, 2014Meng et al, , 2015Zhuang et al, 2014;Zhou et al, 2016). In core D, all P species are positively related to water content, TOC and silt and negatively related to sand (Table 4), which confirms that all P species have common external sources delivered by silt, instead of sand.…”