AceShowbiz - Robert Redford has stepped up to voice his disapproval at plans to begin digging for copper and gold at Pebble Mine because of the proximity to world-renowned wild salmon streams in Bristol Bay.

Robert Redford claims it's "an environmental tragedy waiting to happen" and he's urging others to campaign against the mine.

In a blog post for HuffingtonPost.com, he writes, "Their Pebble Mine would be gouged out of an American paradise - filled with salmon, bears, moose, caribou, wolves and whales - that has sustained Native communities for thousands of years."

"Imagine a pit two miles wide by 2,000 feet deep, and an underground mine a mile deep. This gargantuan gold and copper operation would produce an estimated 10 billion tons of contaminated waste - 3,000 pounds for every man, woman and child on Earth. Massive earthen dams - some taller than the Three Gorges Dam in China - would be constructed to hold back that waste forever. Now imagine all this in an active earthquake zone at the headwaters of the largest sockeye salmon runs in the world. The threat to Bristol Bay just below is unimaginable."

But Robert Redford insists he's not entirely opposed to mining, he just objects to "putting mega-mines where they don't belong".

The veteran star has also lent his support to the Natural Resources Defense Council by fronting a newspaper advertisement appealing to the mining firms behind the Bristol Bay proposal to leave the area alone.