2016 ADPH Fish Advisories

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The average individual has eight amalgam fillings and could absorb up to 120 micrograms of mercury per day from their amalgams. These levels are consistent with reports of 60 micrograms of mercury per day collected in human feces.12 By way of contrast, estimates of the daily absorption of all forms of mercury from fish and seafood is 2.3 micrograms and from all other foods, air and water is 0.3 micrograms per day. 13 Currently, Germany, Sweden and Denmark severely restrict the use of amalgams.1

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A lot of the mercury warning stuff is pretty selective. Most of us have plenty of mercury in our mouths (see above, link below). I have a feeling that a lot of the warnings about mercury in fish is driven by EPA campaign against coal burning (disclosure: I am a mining engineer and worked for coal mining companies for 10 years).

Mercury Toxicity and Systemic Elimination Agents ? Information and Sources

It not just that its mercury, its the type of mercury.

The mercury that was used in fillings (and old thermometers & thermostats) was metallic mercury, almost non-reactive and not readily made biologically available. As in if you have metallic mercury in your mouth and actually swallowed some, it just gets passed right on through or filtered out quickly, not really a problem.

The problem is methylmercury, which is a highly biologically available form of mercury.
Methylmercury is created when metallic mercury is deposited into aquatic environments and then processed by certain bacteria. This type of bacteria is especially prevelant in the sediments of tannic coastal rivers & backwaters.
The mercury, whether natural or man-sourced, gets into the sediment, is processed by these bacteria into methylmercury and then move up the food chain, bringing the methylmercury along with them to be bioaccumulated. Think bug eat lots of bacteria, little fish eat lots of bugs, bass eats lots of little fish. Bass get all the mercury from all the food chain and doesn't expel it, but stores it in fatty tissue.
Oily long lived top predators such as kings, tuna, swordfish tend to bioaccumulate more mercury than short lived species like specs, mahi or Spanish macs.

The interesting thing to me is that while this methylmercury does not seem to effect the fish, it sure does seem to effect humans (if exposed to enough, look up Minimata disease, scary). Probably because fish evolved a way to store the mercury found in these ecosystems, like storing it in the fatty tissue.

What Carl said. I "knew" that but posted the link during a prolonged brain fart.

:barbershop_quartet_

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Originally Posted by CarlF

The interesting thing to me is that while this methylmercury does not seem to effect the fish, it sure does seem to effect humans (if exposed to enough, look up Minimata disease, scary).

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Carl, here is what I'm getting at -- I don't see any evidence in any literature anywhere of measurable harm done by consuming fish with the mercury levels we see in our gulf fish. The Minimata tragedy is a totally different situation. By some accounts, the levels of mercury in sediment there was enough that it would've been economically viable to mine!

Interesting study on mercury in the Gulf, Gulf fishes and people:
http://people.seas.harvard.edu/~swof...Sunderland.pdf


http://oceana.org/sites/default/file...port_Final.pdf (Look at the top of page 6 on this one.)

From the top of page 7 & to Pierless's point.

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Fifteen participants (23%) reported one or more symptom of mercury toxicity listed on the survey. Numbness or tingling in extremities, memory problems, and headache, were the most reported symptoms. Three participants had been told by their doctors that they had a problem with their nervous system. There was no correlation between mercury levels and reported symptoms, however.

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(My Emphasis)

You makes your choice and you takes your chance.

From page 9 of the Oceana report:

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A recent study reported mercury poisoning resulting in visual loss in a British male with mercury levels a little over 2 times the EPA mercury reference dose.16 This individual reported consuming 10-12 fish meals per week, most of which were red snapper from the Caribbean.

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I think that's a little misstated. His level was over two times the EPA recommended maximum and 10 times the US average (albeit the average is not well established).

BUT, we do seem to have here a documented case of problems.

Link to report (reference 16):Diet?related mercury poisoning resulting in visual loss

Let's stop arguing about the effects of mercury and start talking about how people get dumber the closer they live to a city. I think there is some real validity to that line of thinking. By the way, I don't live within two hours of a large city, so I am brilliant. :)

Well, I feel better after reading this, as it only mentioned flounder from the upper bay and estuary of Mobile, and not a thing about pompano and whiting, the species we target surf fishing. I will never become pregnant, so that is a good thing, but we share what we catch with friends and family. Flounder, pompano and whiting appear safe, at least for now.

I appreciate the thoughtful discourse and good research! I must admit the case of the 36 year old man eating 10-12 snapper per week does look like a legitimate case of mercury toxicity.

I do not doubt that there is mercury in fish, and enough mercury will cause symptoms, but it takes a LOT. I suppose my issue with the entire thing is the amount of attention it gets and the rather limiting consumption guidelines imply a much larger risk than what risk truly exists.

I actually did have my hair tested for mercury in high school. I clocked in at 10x the suggested upper limit. However, I never had any symptoms, and I am pretty confident my brain was working pretty well as this was right before I aced both the ACT and SAT.