Determination of Hg and Cd Content in Fish Samples from the River Khrami

Abstract

The River Khrami, flowing through eastern Georgia's Shida Kartli region, is a vital water resource whose ecological condition has recently deteriorated. Pollution from industrial, agricultural, and domestic waste, threatens both its ecosystem and its usability. its tributary, the Mashavera, exacerbates the issue by introducing heavy metals into the Khrami, primarily due to a large polymetallic ore mining and processing enterprise in the Bolnisi municipality. Heavy metal pollution of the Khrami threatens aquatic animals and plant diversity also preventing the sustainable use of water resources.

Heavy metal contamination, especially cadmium (Cd) and mercury (Hg) endangers aquatic biodiversity and hampers the sustainable use of water resources. Fish, being sensitive bioindicators, help assess ecological health, as heavy metals accumulate in their bodies due to their solubility in fat.

In October 2024, we conducted research on local fish, using modern, EU-standard methods and equipment. The research revealed low concentrations of Cd and Hg in the fish, indicating that, despite ongoing anthropogenic pressures, the river water is not currently polluted with these metals and poses no significant threat to aquatic life.

Although the water of the Khrami is not polluted with cadmium and mercury, and therefore does not threaten fish and other aquatic organisms, continuous eco-chemical monitoring is necessary to detect potential increases in heavy metal concentration. Such monitoring helps prevent future contamination that could lead to the poisoning of aquatic organisms, reduced biodiversity, and degradation of natural landscapes.