Uptake and loss of methylmercury-203 by bluegills (Lepomis macrochirus)

Abstract

to imply that both samples have the same origin, since this is unlikely; however, the analysis shows that the sample was definitely a No. 6 fuel oil. ConclusionWe have recorded infrared spectra of over 50 different petroleum samples; absorptivities of 21 bands between 650 and 1200 cm™1 can be used to characterize the samples. Stored in a computer file, the 21 absorptivities of every known sample can be compared with those of any unknown sample at a later date. Using the ratios of known to unknown absorptivities, an unknown can be matched to a known in a matter of seconds.The method of analysis presented here is rapid and, for the 50 plus samples we have studied, it provides an unambiguous identification for petroleum products, eliminating the need for adding tracer materials to petroleum products or for other methods of analysis. Ideally, for the method to be used on a worldwide scale, infrared spectra of all possible petroleum samples would have to be measured and the absorptivities of the selected bands stored in a computer file. This could all be accomplished within a relatively short period of time. In addition, to identify samples taken from natural waters, the effects of weathering on the infrared spectra of samples have to be known.Currently, we are investigating these effects and will report on them shortly.

Biomagnification of mercury in a marine grazing food-chain: algal cells Phaeodactylum tricornutum, mussels Mytilus edulis and flounders Platichthys flesus studied by means of a stepwise-reduction-CVAA method

“…5) is in accordance with similar findings In both fish (Burrows & Krenkel 1973, Olson e t al. 1978) and mammals (Norseth & Clarkson 1971, Rabenstein 1978.…”

Bioaccumulation kinetics and exposure pathways of inorganic mercury and methylmercury in a marine fish, the sweetlips Plectorhinchus gibbosus

“…Whether there was any biotransformation (methylation and demethylation) within the fish body was not revealed by our study. Pennacchioni et al (1976) suggested that fishes are unable to methylate Hg in vivo, whereas other studies indicated that methylation and demethylation are possible (Burrows & Krenkel 1973, Simon & Boudou 2001). We found a significant difference in the AE, the uptake rate constant, and the elimination rate constant between Hg(II) and MeHg.…”

“…gills, brains, viscera) has not been extensively quantified. There is some evidence of considerable methylation and demethylation in fish muscle (Burrows & Krenkel 1973, Simon & Boudou 2001, although some studies have also indicated that fishes are unlikely to methylate the inorganic Hg to MeHg within their tissues in vivo (Pennacchioni et al 1976).…”

“…gills, brains, viscera) has not been extensively quantified. There is some evidence of considerable methylation and demethylation in fish muscle (Burrows & Krenkel 1973, Simon & Boudou 2001, although some studies have also indicated that fishes are unlikely to methylate the inorganic Hg to MeHg within their tissues in vivo (Pennacchioni et al 1976).In this study, we examined the biokinetics of both Hg(II) and MeHg in a marine predatory fish (the sweetlips Plectorhinchus gibbosus) during both the aqueous and dietary phases. Sweetlips is important fish species widely cultured in China, and is used either as fish food or for direct human consumption.…”

Final Report on the Aquatic Mercury Assessment Study

“…Aqueous mercury levels are affected by many factors including oxygen concentration, precipitation, temperature, water level, and wetland runoff (Sellers et al 2001, Hurley et al 1998a, Regnell et al 1997. Although less variation would be expected in fish muscle tissue (Downs et al 1998, Foster et al 2000, where the biological half life of mercury can be one to three years (McKim et al 1976, Burrows andKrenkel 1973), at least one study suggests substantial seasonal variation in fish tissue mercury as a possible consequence of variations in mercury uptake (Park and Curtis 1997). Also, localized aggregations of fish from the same water body may exhibit significant spatial variations in mercury concentration as a likely result of differences in mercury bioavailability among foraging areas (Munn and Short 1997).…”