MISSOULA — In an effort to learn more about contamination at the Smurfit-Stone Mill site, concerned citizens may recruit some unusual assistants: ospreys.
On Thursday, University of Montana ecology professor Erick Greene explained why he thought ospreys might be able to help the Smurfit-Stone Mill Site Community Advisory Group learn more about how the site contaminates the Clark Fork River.
Ospreys are handy for studying what’s going on with water quality because they sit at the top of the aquatic food chain, eating large trout that have fed on smaller organisms in lakes and rivers. If technicians sampled those small fish and aquatic insects, there might not be enough toxins to register as a problem. But through a process called “bioamplification,” toxins accumulate in a big trout that eats a lot of little fish and accumulate more when an osprey eats a lot of big trout.
“Ospreys can have 10,000 times the levels of toxins concentrated in their tissues and blood. So they represent what’s going on in the ecosystem around them,” Greene said. “That’s important for human health, because they eat a lot (of trout) that people eat. If we’re seeing problems in ospreys, then we should be thinking in terms of pregnant women and children and what they should be eating.”
One of the contaminants Greene is concerned about is mercury, one of the most toxic chemicals on Earth. It doesn’t take much to harm human health. The limit is 5 parts per billion.
So Greene used his osprey corps to see if mercury is a problem.
For the past dozen or so years, Greene has located about 200 nests in strategic places around western Montana. At those nests, he temporarily kidnaps chicks every year to tag them and sample their blood and feathers.
Most recently, he’s focused on nests along the Clark Fork River to see how mine-related heavy metals – arsenic, copper, zinc, lead and cadmium – affect water in the upper Clark Fork Superfund site.
The good news is, for the most part, those metals aren’t a threat anymore. The bad news is he’s found dangerous levels of mercury, especially in those osprey nesting downstream of Drummond and those below the Smurfit-Stone site.
The mercury near Drummond is caused by runoff from old placer mines above Philipsburg, where miners used mercury to pull gold and silver out of the ore.
But what makes Smurfit have high levels of mercury, Greene said, is all the shallow ponds, where bacteria turns atmospheric mercury from coal emissions into more toxic methyl-mercury. The same thing happens in any swampy area with decaying vegetation that fosters a lot of bacteria.
“What we’ve seen is ospreys nesting just downstream have really high levels of mercury, about 1,500 parts per billion, so there’s something going on at Smurfit Stone,” Greene said.
Greene offered to set up a project to sample birds above and below the mill site to better analyze the mercury problem in the river and to look at dioxins, furans and PCB’s, which are the main contaminants at the site.
The only barrier is money – it costs about $1,000 to run each bird’s blood analysis, 10 times as much as it cost Greene to test for heavy metals.
“Ospreys have shown us that it’s a really powerful, relatively easy way to get a handle on some pretty important questions,” Greene said. “We could easily modify our approach to focus specifically on the issues you folks are concerned about. Eight nests would be $8,000. Ten grand and you could do a really nice study.”
David Schmetterling, Montana Fish, Wildlife & Parks fisheries biologist, has spent two summers collecting trout around the mill site for tissue samples, and he encouraged the effort.
“This is something we talked about from day one. Fish were just a low-level beginning step,” Schmetterling said. “Looking at other receptors, other organisms that eat fish has definitely been the plan the whole time.”
The advisory group agreed to write a letter to the Environmental Protection Agency asking to add the osprey study.
Contact reporter Laura Lundquist at email@example.com.