Mercury in the global ocean: three times more mercury in upper ocean since the Industrial Revolution

[theHandpuppet]

http://www.sciencedaily.com/releases/2014/08/140806134521.htm
Mercury in the global ocean: three times more mercury in upper ocean since the Industrial Revolution
August 6, 2014
Source: Woods Hole Oceanographic Institution

(excerpt)
It would seem that, if we want to regulate the mercury emissions into the environment and in the food we eat, then we should first know how much is there and how much human activity is adding every year," said Lamborg, who has been studying mercury for 24 years. "At the moment, however, there is no way to look at a water sample and tell the difference between mercury that came from pollution and mercury that came from natural sources. Now we have a way to at least separate the bulk contributions of natural and human sources over time."

The group started by looking at data sets that offer detail about oceanic levels of phosphate, a substance that is both better studied than mercury and that behaves in much the same way in the ocean. Phosphate is a nutrient that, like mercury, is taken up into the marine food web by binding with organic material. By determining the ratio of phosphate to mercury in water deeper than 1,000 meters (3,300 feet) that has not been in contact with Earth's atmosphere since the Industrial Revolution, the group was able to estimate mercury in the ocean that originated from natural sources such as the breakdown, or "weathering," of rocks on land...

...But determining the contribution of mercury from human activity required another step. To obtain estimates for shallower waters and to provide basin-wide numbers for the amount of mercury in the global ocean, the team needed a tracer -- a substance that could be linked back to the major activities that release mercury into the environment in the first place. They found it in one of the most well studied gases of the past 40 years -- carbon dioxide. Databases of CO2 in ocean waters are extensive and readily available for every ocean basin at virtually all depths. Because much of the mercury and CO2 from human sources derive from the same activities, the team was able to derive an index relating the two and use it to calculate the amount and distribution of mercury in the world's ocean basins that originated from human activity.

Analysis of their results showed rough agreement with the models used previously -- that the ocean contains about 60,000 to 80,000 tons of pollution mercury. In addition, they found that ocean waters shallower than about 100 m (300 feet) have tripled in mercury concentration since the Industrial Revolution and that the ocean as a whole has shown an increase of roughly 10 percent over pre-industrial mercury levels.... MORE at link provided above.

[merrily]

1. The ocean was once thought to be our fall back source of food.

But, they poisoned that, too.

If anyone ever tells you that taxing rich people more is unfair, remember what they have done to air, water, soil and the food supply, jto name just a few.

[DocwillCuNow]

2. Geez, we once taught that cigarettes promote digestion and a whole host of other things,

PG and E told Erin Brockovich that hexavalent chromium was a nutrient, why don't we just consider mercury a nutrient as well, then everything will quiet down and people will think they are getting something for nothing when they eat tuna. Too bad mercury is the most potent neurotoxin known. I really think we should put it back in dental fillings, remember that argument?