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Environment responses between carps' otolith minerals and their different living environments, Baiyangdian Lake (BL), seriously polluted, and Miyun Reservoir (MR) little polluted, were studied based on XRDA, EPMA, NAA and LA-ICPMSA.
All samples from two sites are composed of vaterites. The dimensions of samples' crystalline cells of vaterites from MR are more nearer to vaterites' standard crystalline than those from BL; the a0 and the cell volume of the former are relatively nearer to standard than the latter, but c0 are reverse.
The thermoluminescence curve parameters of the fish otoliths from BL are greater than those from MR accordingly. At the same testing temperature, the escape probility (α) of the former is bigger than the latter, and energy gap (E) inversely.
The main differences for elements contents in otoliths from the two sites are Sr, Zn, As and Ba. Sr and Zn occupy the like ion sites in the crystalline structure, but different for As and Ba. Comparing with otoliths from MR, the contents of As, Sr and Ba elements within otoliths from the BL show abnormal intermittently, Na waved intermittently, Zn abnormal continuously, Au unvaried at large, and K nearly same as the MR. These abnormal contents of elements may be in relationship with intermissive drain contamination from local manufactories and domestic garbage.
At large, from Sept. 2004 to 2002, for the curve of elements concentrations within otoliths from the BL, elements concentrations vary relatively larger in the rings near the annuli, with moment high values, than other rings. The situation for those within otoliths from the MR mainly divided into two stages. From 2004 to 2003, elements contents varied relatively slightly; but from the winter of 2002 to 1997, varied relatively large; lots of elements concentrations appear high at the period of spring and summer seasons of a year.
For the trace elements contents within otoliths, dynamic responses to aquatic environment hydrochemistry are different due to different otolith types. The contents of elements Sr, K, Na, Ba, Zn, Cr, Fe, As, Au in the asteriscus otoliths and the contents of elements Sr, Na, Ni, Cu, Zn, Pb, Cr, Co within the lapillus otoliths are under the influence of their contents in the water; these elements can be used as the target elements to monitor environmetal hydrochemistry.
Distinct discriminations for trace elements concentration in otoliths from these two sites are shown by otoliths¡¯ mineral crystalline structures and their cell parameters, characteristics of thermoluminescence curves, and contents of trace elements. Elements¡¯ concentrations in different period in the water are revealed by contents of these elements within otoliths as well. These mineralogical characteristics can be used as reliable hydrochemical proxies; and otolith mineral is a kind of material to monitor aquatic environments. This paper is financial supported by the Chinese ¡°973¡± project (2007CB815604), NSFC project (40473044).
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