Assessment of Mercury Concentrations in Water and Fish Tissue Analysis in Kaw Lake, Oklahoma, 2022

Abstract

The Kaw Nation has been collecting water, sediment, and fish samples from Kaw Lake and upper Arkansas River from 2007 to present to examine the concentrations of Mercury and other heavy metals to protect the health of the tribal members. Kaw Lake is in the North-Central part of Oklahoma. Kaw Lake is a permanent water body constructed in 1976 by the Army of Corps of Engineers. The Lake is consistently fed by the Arkansas River and other tributaries as runoff coming all the way from Colorado through Kansas to Kaw Lake of Oklahoma. The Lake has a surface area of 26.64 square miles (69 km 2 ) and shoreline of 168 miles (270 km) with a total drainage area of 56,345 square miles (145,393 km 2 ) and an average water depth of 8 meters. The water and fish samples were collected from 7 sites of Kaw Lake, once in a month and the fish samples once in a year during summertime, early July to end of July. The fish samples focused on 5 sport, predator, and bottom dwelling species of large consumable size, greater than 200 mm length and 560 grams weight. The five fish sampled were Catfish, White bass, Largemouth and Smallmouth bass, Black and White crappie. The fish and water samples were sent to Accurate Environmental Labs for detailed analysis. Predator species were analyzed as fillet and the bottom dwellings as a whole fish using EPA Method 7471A-M. Mercury from Water and Fish Tissue Samples were analyzed by Atomic Fluorescence Spectrometry. The laboratory analysis indicated that all the Mercury concentration in the fish samples except in Blue Catfish and Spotted Bass fall below the Maximum Contaminant Level (MCL) of 0.5 mg/kg.

Bioremediation of environments contaminated with mercury. Present and perspectives

“…The levels of Hg can be found in terrestrial vertebrates intended for human consumption are very low (Emami et al 2023 ; Nava et al 2023 ). However, numerous authors collect evidence of a high concentration of Hg in fish (Alemayehu et al 2023 ; Frías-Espericueta et al 2023 ). Despite the high concentration of Hg that can be found in the oceans, studies such as those conducted by Li et al ( 2022b ), show how water from rivers and lakes have a higher concentration of Hg than open waters and coasts.…”