What is about rivers that attracts hard rock mining? The last BRTU E-News told about the toxic legacy that hard rock mining has bequeathed the Upper Clark Fork River, and earlier issues have focused on the Black Butte Mine in the Smith River drainage and the Pebble Mine that threatens a priceless natural treasure in Alaska.

Well, the latest travesty to make the news is a gold mine that the mining conglomerate Atlantic Gold wants to construct alongside Nova Scotia's St Mary's River. Atlantic salmon devotees will recognize that decades of conservation work and millions of dollars have restored salmon runs on this river. In addition, the St Mary's is home to undisturbed old growth forests and other unique ecological features.

The mining industry is very welcome in Nova Scotia and the provincial government promotes the economic benefits. If this sounds familiar, it is become the same playbook and script are used for every project. 

You can read a good story about the mine and efforts to halt it in this story from the Guardian, which was also the source for the photos.

The amount of precious metals from typical mines never amounts to more than ounces from tons of excavated material. And to liberate the gold, it is often necessary to treat the ore with toxic materials, like cyanide, in large lined pits like a kid's wading pool and retain the material behind dams. And the rock often contains other heavy metals like cadmium. When - not if - the dams fail, a muddy slurry of poisons is regurgitated, often into streams as occurred in the 2014 Mount Polley dam disaster in Alberta when more than 20 million gallons of toxic sludge poured into a lake that is home to a significant portion of the salmon in the Fraser River. Science, the journal of the American Association for the Advancement of the Sciences, recently dedicated the August 21 issue to mud, and, although all the articles are really interesting, the one entitled "A Dam Big Problem," focuses on tailings dam failures from Canada to China to Brazil.

The damage to fish is thought to occur when the fish are under stress from high water temperatures and the parasite starts to reproduce damaging the fish's innards and causing the kidneys to swell. Under normal water conditions, the parasite is still present, but does not appear to cause any problem. The environmental factors that govern the severity of Aquatic Invasive Species (AIS)  outbreaks, like temperature, are really intriguing and not well understood.

In late August, another whitefish die off was noted in the same area. Although the cause has not yet been reported, it seems likely that this represents another outbreak of PKD since the flows were low and the water temperatures were elevated. According to the story in the Missoulian, MFWP is not planning any closures at this time.

On August 18, a different well known AIS was detected at the MFWP Bluewater  trout hatchery in southcentral Montana near Bridger. This time it was New Zealand mudsnails. These little babies were first detected in mid-1990s in the Madison drainage above Hebgen Lake, and are now present in several river systems. Bluewater Creek is a tributary of Clark's Fork of the Yellowstone.

The hatchery will be quarantined and MFWP will try to determine if any infected fish got stocked out. You can read more here.

Last September, these critters were detected in a hatchery in the Bitterroot, but after intensive disinfection efforts, in early 2020 the infestation was reported eliminated.