Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

Abstract

A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish.

Modulation of selenium tissue distribution and selenoprotein expression in Atlantic salmon (Salmo salarL.) fed diets with graded levels of plant ingredients

“…Furthermore, the Se content of liver was three and seven times higher in comparison with the kidney and muscle, respectively, whereas the lowest Se concentrations were found in brain and gill. This is in agreement with Burger et al (48) who indicated that levels of Se were similarly low in brain and gill of bluefish (Pomatomus saltatrix), but in the previous study the highest Se content was found in head kidney.…”

The effect of ascorbic acid on mercury-induced changes on the histomorphology of the cerebellum of adult wistar rats

“…Recent studies have shown that the most sensitive elements of the cerebellar cortex to these chemicals are the Purkinje cells, which react to these noxious substances by undergoing degeneration and as such disappear from their relative positions in the Purkinje cell layer (Jomova and Volko, 2011;Farina et al, 2013). It has been shown that cerebellar dysfunction may occur in association with exposure to a wide variety of toxins including heavy metals such as mercury, lead, thallium, manganese, drugs and solvents (Woodside et al, 2005;Burger et al, 2013). These toxins may adversely affect the cerebellum directly or as part of a more generalized brain effects (Jomova et al, 2011).…”

Selenium/mercury molar ratios in freshwater, marine, and commercial fish from the USA: variation, risk, and health management

“…Saltwater fish (including marine and estuarine species) were collected from New Jersey (2003-2011) (57,99,100) and from the Aleutians in Alaska (2003-2005) (101). Freshwater fish were collected from South Carolina (1997-1998) (102) and Tennessee (103).…”

“…Although the variation in Hg levels among fish has been noted in numerous articles, variation in Se levels in fish has seldom been examined and the Se/Hg molar ratios are given in only a handful of articles (96,100,101,103) and can be calculated from only a few others (14,115).…”

“…The factors that contribute to variations in Hg (species, size, age, trophic status, location) and the lack of correlation of Se with size suggest that Se/Hg molar ratios might generally decrease with levels of Hg and decrease with size, especially for larger predatory fish (100). For many saltwater species, the Se/Hg molar ratios decrease with size, although this is not always the case (101,123).…”