Interactive accumulation of mercury and selenium in the sea starAsterias rubens

Abstract

Abstract.Interactions between mercury and selenium accumulation and subcellular binding in Asterias rubens (L.), collected in 1987 from Lille Belt at Middelfart, Funen, Denmark, were investigated in laboratory experiments. Sea stars exposed to 10 #g Hg 1 -~ for 30 d accumulated mercury in body wall, tube feet and stomach linearly with time at 1.2, 1.2 and 0.5 #g Hg g -t dry wt d-1, respectively. Mercury was accumulated in pyloric caeca and coelomic fluid initially at 1.4 #g Hg g-1 dry wt d-x and 9.4 ng Hg ml-1 d-~, respectively; after 10 d uptake rates decreased. Sea stars exposed to 75 #g Se-SeO;--1-1 accumulated selenium linearly with time over 30 d in the stomach, pyloric caeca, tube feet and body wall at 2.0, 1.2, 1.2 and 0.6 #g Se g-1 dry wt d-1. Sea stars exposed to 75 #g Se-SeO 4 -1-i maintained selenium levels in the coelomic fluid at 75 #g Se 1-1 over 30 d. Exposure to selenate did not alter the selenium concentrations in the tissues. Sea stars exposed concurrently to 75 #g Se-SeO;--and 10 #g Hg 1-1 accumulated more mercury and selenium in tube feet and body wall than did sea stars exposed to the two elements alone. In pyloric caeca and stomach concurrent exposure reduced accumulation of both elements. Mercury was bound predominantly in the insoluble fraction of the tissues, and soluble mercury was bound in proteins of high (> 70 kilodaltons) or very low (< 6 000 daltons) molecular weight. Ca. half of the selenium recovered was bound in the insoluble fraction, and soluble selenium was bound in proteins of high (>70 kilodaltons) or very low (<6000 daltons) molecular weight. Interaction between the two elements was exerted predominantly in the insoluble fraction of the tissues.

Accumulation of organic and inorganic mercury from food in the tissues of Carcinus maenas: effect of waterborne selenium

“…Inorganic and organic mercury were determined accordmg to RiisgArd & Hansen (1990) and selenium and total mercury (in carapace) were analysed as described by Sarensen & Bjerregaard (1991). Tissue homogenisation and gel filtration procedures used in the determination of the subcellular distribution of mercury and selenium were described in Bjerregaard (1990) …”

Field contamination of the starfish Asterias rubens by metals. Part 1: Short‐ and long‐term accumulation along a pollution gradient

“…These aspects have been extensively studied in the mussels, making them paradigmatic bioindicators and prompting their use in biomonitoring studies [3]. Contaminations of A. rubens by metals have been studied in short-term experimental conditions and in natural populations [6][7][8][9][10][11][12][13]. Among these, the starfish Asterias rubens has received some attention considering its ecological importance and availability in some marine benthic ecosystems [5].…”

O selênio no meio ambiente

“…A toxicidade do selênio é bem documentada e foi revisada sob vários pontos de vista, tais como o de um toxicologista marinho (Saiki 1986), toxicologistas da vida selvagem (Ohlendorf 1989, Skorupa 1998, um ecologista (Maier et al 1987), um químico (Presser 1994), um modelador (Bowie et al 1996, um especialista em selênio (Lemly 1999a) e outros especialistas (Davis et al 1988, Sorensen 1991, Hamilton 1998. E todos concordam que a bioacumulação e os efeitos tóxicos do selênio em peixes e animais marinhos resultam primariamente da transferência via cadeia alimentar.…”