Mercury concentrations in three species of fish from North Atlantic offshore waters

Abstract

Mercury concentrations were determined in tissues and organs of spiny dogfish (Squalus acanthias), cusk (Brosme brosme), and blackbellied redfish (Helicolenus dactylopterus) collected from Atlantic Ocean waters off the northeastern coast of the United States. Information was obtained on the spatial and temporal distribution of mercury in the organs and tissues of these fish.

Cusk were obtained from 2 locations and blackbellied redfish from 4 locations. The mercury levels in both muscle and liver of cusk averaged about 0.30 ppm for one and 0.16 ppm for the second location. Gills and kidneys of cusk had mercury levels that averaged 0.08 ppm for both collections. In blackbellied redfish mercury levels in muscle and liver averaged about 0.08 ppm for all locations; gill and kidney tissues of this fish were less than 0.2 ppm.

Spiny dogfish were obtained from 5 areas. No significant difference in mercury levels was found in muscle tissue as related to geographic area. Mercury levels ranged from 0.21 to 0.62 ppm. The kidneys of dogfish contained about 54% of the mercury level of muscle. The mercury level in gills of dogfish ranged from 0.06 to 0.21 ppm.

Spiny dogfish pups were obtained from 6 adult females. Samples of muscle, liver, gill, kidney, and yolk of pups were analyzed for mercury. These same samples, except for the yolk, were obtained from the adult females. Mercury levels in all pup samples were less than 0.03 ppm, while mercury levels in adult females ranged from 0.03 to 1.1 ppm in all tissues and organs.