Thousands of migrating snow geese died after landing in contaminated pit mine waters in Montana.
On Nov. 28, a snowstorm forced the geese to take refuge in the Berkeley Pit, a 900-foot-deep pit water of heavy metals and other toxic chemicals. For years, there had been instances that birds float dead on the waters, but not this much.
Mine workers tried to prevent the birds from landing on the open pit copper mine waste water but were overwhelmed by their number. An estimated 25,000 birds were killed by the toxic and acidic water, The Guardian reports.
The employees of the mining company, Montana Resources, and Atlantic Richfield, who are responsible for the Berkeley Pit in Butte, tried to ward off the birds through spotlights, noise makers and other means.
“I can’t underscore enough how many birds were in the Butte area that night,” Mark Thompson, an environmental affairs manager for Montana Resources, said as reported by BBC News.
“Numbers beyond anything we’ve ever experienced in our 21 years of monitoring by several orders of magnitude,” he said, adding that they only see between 2,000 and 5,000 birds each year during summer and winter migrations.
In fact, between 2010 and 2013, the Environmental Protection Agency (EPA) has reported only 14 snow goose deaths in the said pit.
This is not the first time that this incident happened. In 1995, 342 geese landed on the pit and suffered fatal burns to their trachea and other internal organs after drinking the toxic water.
Researchers believe that the birds were forced to land on the contaminated pit because of an incoming storm. They also went through a late-season migration due to the warming temperatures in their northern Arctic habitat. The open pit is the only open area containing water, so the birds were forced to land in their search for water.
The companies plan to investigate to determine the circumstances that had led to this incident, leaving thousands of birds dead.