Bioaccumulation of heavy metals Cu, Zn, and Hg in muscles and liver of the stellate sturgeon (Acipenser stellatus) in the Caspian Sea and their correlation with growth parameters



Bioaccumulation of Cu, Zn, Hg in muscles and liver
tissues of stellate sturgeon (Acipenser stellatus) from the southern
Caspian Sea was measured.
Effects of condition factor (CF), age and hepatosomatic index (HSI) on metal accumulation
were also determined. Some 40 stellate sturgeons were collected using gill nets
in winter and spring 2007-2008 from the southern shores of the Caspian Sea.
Total (TL) and fork (FL) length and weight of all specimens were measured. Cross sections of first ray of pectoral fins were used
for age determination. Muscle and liver samples were taken and
transported to the laboratory in ice packs and kept in -20 oC prior
to analyses. In the laboratory samples were oven dried, digested with HClO3
and HNO3 and diluted with dionized water to 50cc to measure Cu, Zn,
and Hg concentration with a flame spectrophotometer. Sequence of metals in Acipenser stellatus was Zn>Hg>
Cu in muscle tissues and Zn> Cu> Hg in liver samples. Concentration of Zn was
slightly in correlation with age (R= 0.3). A negative correlation was observed
between Zn concentrations with condition factor (R= -0.3). Zn concentrations were
negatively correlated in muscle tissues (R=-0.3). The results were compared to
international standards proposed by MAAF, EEC and NHMRC. Our study showed that
accumulation of heavy metals in sturgeon tissues was influenced by
concentration of metals in sediment and the physiological state of fish.