Scientists Trace Mercury Contamination To Fish In Remote Voyageurs NP

[hatrack]

Evidence that links atmospheric mercury to methylmercury in fish is mounting in the scientific literature. In a paper published today on ES&T’s Research ASAP website (DOI: 10.1021/es060822h), researchers strongly identify atmospheric deposition as the source of mercury contaminating fish living in Voyageurs National Park. The study comes just weeks after another ES&T paper reported similar conclusions from the Experimental Lakes Area in northern Ontario, Canada.

Voyageurs National Park, in northern Minnesota, is a relatively pristine region with no point sources for mercury. Two of the park’s lakes, however, contain fish with some of the highest mercury concentrations in the state, and the federal government posted fish consumption advisories in the mid-1990s.

To determine the source of mercury in Voyageurs National Park and how it ends up in fish, a team of researchers led by Jim Wiener of the University of Wisconsin–La Crosse measured mercury in bedrock and soils, and they statistically modeled lake and wetland functions. To study the food chain, the team analyzed 1-year-old yellow perch, which are eaten by loons and larger fish. One of the perch’s predators, the northern pike, was also tested; those data will be published later.

The team found negligible geologic sources of mercury in 17 of the area’s lakes and in the stream or groundwater catchments that feed them; however, sediment cores record that airborne mercury accounted for two-thirds of total mercury accumulated after 1900. The researchers concluded that atmospheric deposition from anthropogenic activities dominates the contemporary source of mercury pollution. Atmospheric mercury deposition appears to be the only factor in the ecosystem that doesn’t vary spatially, Wiener points out, referring to data from the Mercury Deposition Network. Between lakes, mercury levels in the perch varied 5-fold, whereas mercury levels in the pike varied 10-fold. Such variations, the team says, are caused by differences in wetland and lake behavior.

EDIT

http://pubs.acs.org/subscribe/journals/esthag-w/2006/sep/science/nl_pristine.html

[havocmom]

1. Bald eagles in Montana have problems with toxic levels too.

BLM is lanuching a study of the birds in the Yellowstone & Powder River drainage areas.

[Botany]

2. damn them!

It is coal

[opihimoimoi]

3. Most likey the result of some Human activity??

[hatrack]

4. Almost certainly coal-fired power plants

Mercury is deposited on the leaves, into the water, etc., and changes into methylmercury, an organic mercury compound found in fish, insects, the food chain, and so on . . .

[opihimoimoi]

5. We Humans have reaqched a point of being our own worst enemies

Where is the Big Picture and what are the SOLUTIONs?

[Botany]

6. at these levels mercury almost certainly is coming from coal fired ....

.... power plants.

We have the technology to take it out of the off gases too. But * weakened the laws.

I love that part of the world too.