Northern Australia, whither the mercury?

Abstract

Biomagnification of mercury (Hg) leads to high concentrations in fish and subsequent health risks for fish-eaters. Despite the global concern afforded to Hg over the past 40 years, little attention has been paid to this toxic heavy metal in Australia in general, and tropical northern Australia in particular. This review examines past Hg research in Australia and explores seven hypotheses as to why so little research and monitoring has been conducted in northern rivers and estuaries. We rule out the possibility that fishing intensity (an indicator of potential Hg exposure in humans) is lower in Australia than in other countries with more intensive Hg research programs. Instead, we hypothesise that low atmospheric deposition, owing to prevailing wind direction and few local point sources, coupled with highly productive waterbodies, contributes to low Hg bioaccumulation and hence the reduced interest in measuring Hg. Outstanding questions regarding Hg in northern Australia include the assessment of atmospheric deposition rates of Hg, the trophic level and growth and food consumption rates of consumers such as large-bodied fishes, linkages between fire regimes and Hg availability, and the capacity for in situ Hg methylation in tropical systems.

Buying seafood: Understanding barriers to purchase across consumption segments

“…Perceived risk associated with seafood consumption pertains to issues of safety, with some consumers being concerned about possible contaminants, treatment with hormones or antibiotics, mercury levels and whether the seafood has been handled in a hygienic manner (Lobb, Mazzocchi, & Traill, 2007;Sioen et al,2007;Vanhonacker et al 2010). Seafood consumers, and in particular those in high risk groups such as young children and pregnant women, may perceive physical risk or risk to their well-being or health, such as choking on a fish bone or unacceptable levels of mercury (Jardine & Bunn, 2010). Lower levels of seafood consumption have been associated with perceptions of physical risk associated with food poisoning from eating seafood (Pieniak et al, 2008;Vanhonacker, et.al., 2010).…”

Manuscript_acp-2016-517: Five-year records of Total Mercury Deposition flux at GMOS sites in the Northern and Southern Hemispheres

“…Measurements of atmospheric Hg deposition in Australia have never been reported before (Jardine and Bunn, 2010). From 2013 till 2015, at Cape Grim GAW Station (CGR), located on the north-western coast of Tasmania, Australia, highest value in rainfall have been observed during winter an lowest in summer, whereas Hg concentrations peaked in summer and dropped to lowest values in winter (see Fig.…”

Mercury in tropical and subtropical coastal environments

“…), but others can be quite unexpectedly local, as for instance medical incinerators (Denton et al, 2011) and mishandling of e-wastes (Robinson, 2009). The mercury burden delivered to coastal environments by atmospheric transport and deposition interacts with local ecological and social patterns (Jardine and Bunn, 2010). So, it is necessary to take this atmospheric contribution into consideration, especially when inventories suggest higher levels of mercury in coastal environmental compartments than the most obvious, waterborne mercury sources, can possibly explain.…”