Research explores fire, mercury link

2002 Missionary Ridge Fire might have led to fish advisories

A helicopter flies past charred trees and scorched earth near Vallecito Reservoir as it carries firefighters to battle the Missionary Ridge Fire in 2002. Enlarge photo

JERRY McBRIDE/Herald file

A helicopter flies past charred trees and scorched earth near Vallecito Reservoir as it carries firefighters to battle the Missionary Ridge Fire in 2002.

Researchers recently received federal funding to continue a study aimed at exploring high levels of mercury found in fish at Vallecito Reservoir, which a researcher at the University of Colorado thinks might be the result of the 2002 Missionary Ridge Fire.

The San Juan Generating Station in Waterflow and the Four Corners Power Plant in Fruitland are believed to be the primary source of atmospherically deposited mercury in La Plata and Montezuma counties.

CU's lead researcher Joseph Ryan thinks that a large wildfire could volatilize latent mercury that stuck to the top layer of soil.

The Missionary Ridge Fire burned more than 70,000 acres north of Durango in June and July 2002. Ryan said a fire of that intensity could have oxidized sulphur molecules that bind mercury in organic matter in the soil.

Ryan said a large wildfire could also introduce mercury into water another way, by speeding erosion and allowing the mercury to wash into a water source.

"Nobody's really looked at this before," Ryan said. "That's probably why the National Science Foundation is funding us."

Ryan has been studying mercury mobility in Southwest Colorado for the last year and a half.

Ryan's initial research was funded by CU sources, but a $690,000 grant from the National Science Foundation recently was awarded to expand his work.

He will collaborate with the Mountain Studies Institute, the San Juan Public Lands Center and Fort Lewis College.

MSI director and FLC adjunct professor Koren Nydick said the institute will hire FLC students as technicians for the project. FLC seniors also will be allowed to develop theses around the project.

Next up, researchers will look for a prescribed burn in the area and gather before and after samples, Nydick said.

Vallecito is one of five reservoirs in the Four Corners with mercury advisories in effect.

The research is exciting in part because similar fish advisories are in effect in nearly every state, said George Aiken, a hydrologist with the U.S. Geological Survey involved with the project.

"Our interest is in a broader understanding of the fate of mercury in the environment," he said. "We're really excited about this. This is an example of fundamental research being done in your backyard."

gandrews@durangoherald.com