Sciencemadness Discussion Board

Mercury in fish

SM2 - 24-8-2012 at 08:45

Intuitively, perhaps once the toxic forms of Hg have reached low or even (especially high) order species, it has bonded covalently and denatralized proteins. Thus, perhaps eating fish with a relatively high Hg content may not be so unhealthy after all. However, if that Hg somehow energetically gets stripped and converted to an alkyl Hg, all bets are off.

Just think it's an intriguing thing to think about - Hg in fish- the damage has already been done. Eating whatever sea ford might be more like eating protein with a little Calomel sprinkled on.

Now X-Ray and gamma from Japan is a whole other story.

DDTea - 24-8-2012 at 13:01

It isn't elemental mercury that bioconcentrates in fish; it is methyl mercury and dimethyl mercury that are absorbed and retained by the fatty tissues of fish that swim in contaminated waters.

The damage has not necessarily been done already. There are compounds present in toxic algal blooms that also bioconcentrate in fish. This is why at certain times of year, barracuda can be poisonous when eaten. Think about it: barracuda are not venomous or poisonous animals in and of themselves!

AJKOER - 24-8-2012 at 13:48

OK, in my opinion, the questionable good news is that inorganic Hg compounds released into the atmosphere (chiefly from ongoing and increasing coal burning) are turned into CH3Hg+ (the monomethylmercury(II) cation) by aquatic anaerobic organisms. So detection and cleanup need to chiefly focus on this cation.

The bad news is that it is highly toxic to marine life which, in itself, has not been an historic course changer for policy makers (for example, the death/dying of coral reefs throughout the world, isn't front page news, if news at all). But, as the methylmercury presence is now significant enough to poison people (and perhaps, therefore, selfishly important), there is more pressure to alter bad policy (which I, for one, consider good news).

Now, in America, it is probably wise for an industry (like fishing) that could be the blunt of a serious economic impact (as the fear of eating any fish spreads) to act early. This is due to the fact that a weak/declining US industry has increasingly diluted lobbying/political power to effect change in their interest. Now normally, this is a constructive process, but in this case, for those with a longer term prospective of having to live on planet Earth, perhaps not.


[Edited on 24-8-2012 by AJKOER]

SM2 - 30-8-2012 at 18:51

I think you guys know a hell of a lot more than I do.

DDTea - 31-8-2012 at 17:18

In fairness, I have been working in an ecotoxicology lab for almost a year now. In that time, I have done chemical analyses in support of bioconcentration studies in bluegill fish for three different compounds, each lasting ~3 months. I've learned a fair bit about bioconcentration in that time! :)

zed - 8-9-2012 at 11:25

Ah, within walking distance, flows the mighty Willamette River. Therein, one might, with a little luck, land a 400 pound Sturgeon. A lifetime supply. Especially since the huge fish, carry a huge Mercury load.

Healthy adult humans are advised to eat no more than one 8oz portion of Sturgeon per month.



[Edited on 8-9-2012 by zed]