Symposium: Mining pollution impacts bears

A symposium was held Wednesday night at the Nolan Center to discuss the effects of mining on Southeast Alaska's bear population. Lance

Craighead, a bear biologist, said that mining has the potential to have a very negative impact on bears. Most mining, Craighead said, occurs in

nearby British Columbia but anything happening there would literally flow downstream to Alaska.

"In general, Canada has some of the laxest mining regulations in the world next to China," he said. "For that reason they're about one of the few countries that still has big mining operations."

One of the biggest impacts mines can have on bears, and the environment in general, is in pollution. Craighead said that mines generally operate by digging up ore from the earth, and depositing waste into large man-made ponds. These ponds are kept from leaking into the surroundings by a tailings dam.

He pointed out, however, that the tailings dam could fail. Craighead mentioned a proposed mine in British Columbia, which has yet to begin operations. The Galore Creek Mine, as Craighead called it, is proposed to have a 905-foot tall tailings dam. This would be the fifth largest dam in the world, he said. He also said that a tailings dam of similar design failed at the Mount Polley Mine in 2014. According to

Craighead, 6.6 billion gallons of mining waste was spilled.

"A United Nations report said that Canada has had seven known mine dam tails that have failed in the last decade," he said.

Craighead divided the effects mines have on bears into two categories: Direct impacts and indirect impacts. Some of the direct impacts he pointed out include loss of habitat and increased mortality due to hunting and traffic on mining roads. Another direct impact comes from stress. All the new noises, sights, and changes to the surroundings brought on by the mine can stress bears and cause them to spend more time hiding instead of feeding or reproducing.

One of the biggest indirect impacts mining can have on bears is in the way it can affect salmon populations. Salmon are one of the most important sources of food bears have, Craighead said, and 94 percent of nitrogen and carbon in a bear's body comes from salmon. With pollution caused by mining, rivers and salmon spawning sites can become damaged. Fewer salmon would mean less food for bears, he said.

Pollution can also have a negative impact on other bear feeding sites. Bears spend most of the summer and fall near salmon streams, but springtime is spent near shorelines and estuaries. Craighead said that this is because bears are just coming out of hibernation in the spring, and need easy meals. So, they comb the shoreline for clams, dead fish, and other bits of food. Pollution there, he said, will also have a major negative impact on bears.

"Early spring is a critical time for bears," he said.

Before concluding the symposium, Craighead said that it would be very unlikely for mining to have an immediate impact on bears living on islands like Wrangell or Petersburg. Any impact to local populations will come from pollution to the shorelines. Still, he said, mining was bad for Alaska's bear population as a whole.

 

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