Tuna’s Declining Mercury Contamination Linked to U.S. Shift Away from Coal

Could it be because the Tuna being caught are not as old and have not lived long enough to accumulate as much Mercury? I didn't see the age of the fish mentioned in the article. We measured Hg concentrations in 1292 Atlantic bluefin tuna (ABFT, Thunnus thynnus) captured in the Northwest Atlantic from 2004 to 2012. ABFT Hg concentrations and variability increased nonlinearly with length, weight, and age, ranging from 0.25 to 3.15 mg kg–1, and declined significantly at a rate of 0.018 ± 0.003 mg kg–1 per year or 19% over an 8-year period from the 1990s to the early 2000s.

I would advise looking at the source for any graphs/plots - increased nonlinearly literally just means increased but not in a straight line, could be anything.It doesn't mean anything other than it being a relationship that doesn't follow a line. In this paper they are referring to an exponential relationship when they say nonlinear, based on their data. Increased nonlinearly" means: an increasing trend that deviates from a line. The type of nonlinearity is not described, but sqrt(x) would satisfy the definition.

In this context I would take it to mean it increased inversely of sorts. Big jump in mercury per/kg in younger fishes, then increasing but not as much as the fish gets older. They accounted for the age of the fish. Figure 2 illustrates year of capture and mercury concentrations within each age group over time. How about this really obvious factor that these scientists who do this stuff for a living couldn't possibly have taken into account, guys?  The new study, published online on November 10 by Environmental Science & Technology, links the decline directly to reduced mercury emissions in North America. Most of that reduction has occurred because of the marketplace shift by power plants and industry away from coal, the major source of mercury emissions.

That could be why they were confused that it's happening "so fast" when really mercury has been declining since 1990, so a good 1/4 century has gone by already. The majority is only coal because we've decreased other major sources of mercury pollution. Prior to reduction, the major sources were gold mining and waste incineration. Worldwide, these are still the largest sources for mercury pollution. How does this make any sense when China is STILL the worlds leading coal consumer. They use more coal than the US and the rest of the world combined. Anything the US does is completely negated by Chinas increasing usage of coal and other fossil fuels.

You may be right that the amount of mercury in the Pacific's fish more than makes up for the lowered mercury levels in the Atlantic, but the study shows reducing mercury emissions over the Atlantic quickly reduces the amount of mercury in the fish there. Blame Japan (and other parts of Asia) for how much Tuna is consumed.... Its staggering, and they will eat it till its completely gone. People in Japan simply don't seem to have an understanding of what it means to consume something all the way into extinction.

That shit was nice while it lasted, I knew humanity would find a way to botch that up. Business as usual now folks in Trumpistan, nothing to see here, lower your mammoth expectations. Not to worry. Drumpf will have the US using coal again in no time. We'll have those mercury levels back up before you can say "Wait. What?" Could it be that correlation doesn't equal causation? There are plenty of reasons why this could be and doesn't have to be due to our use of coal .