Abstract

Background: Mercury contamination of aquatic systems is a global environmental health threat, and a monitoring
program is useful for generating data that can be aggregated over a period of time for broad synthesis to determine the emergence
of ecosystem characteristics that influence mercury bioaccumulation in fish..
Results: Total concentrations of (Hg) in water and fish were assessed across the Musayyib River/Euphrates which are sites
identified by extreme gradients in habitat structure and water management. All databases were collected at concentrations (Hg) in
30 fish (Liza abu, Cyprinus carpio) from 10 sites in this region and were used to assess the temporal distribution of fish (Hg)
across sites as well as the effects of different species and habitats. High exposure (Hg) sites were identified, and a relative
estimate of fish component concentrations was made at the watershed scale that takes into account fish diversity in species, size,
and site effects. Hg concentrations in fish muscle ranged from 0.01 to 38.4 g/g, with a geometric mean of 0.01. (0.27) , 40 percent
of individual fish samples and 20 percent of the means by sites (0.50 g/g) exceeded the fish tissue standard.
Conclusion: Mercury concentrations in fish were found to be correlated with water mercury concentrations at the watershed
level, implying that factors affecting mercury production may be more important in determining fish exposure to mercury. It was
suggested that as a result of fish exposure to mercury, the spread of mercury throughout the Musayyib/Euphrates River and all
species and habitats of the type should consider an important role in influencing environmental mercury risks in aquatic
ecosystems describe general environmental characteristics and has been used in the management of Iraqi water systems.

Key words: Mercuy, Freshwater, Fish, Pollution of the Environment