Humans can royally muck up the environment, but sometimes we can put things right again. Seven years ago, Vancouver's Howe Sound was a lifeless chemical stew, poisoned by contamination from a copper mine. And now, according to the Globe and Mail, there's this:

Sightings of grey whales, killer whales and schools of hundreds of white-sided dolphins are now being made regularly in the Sound, where massive herring spawns are once again occurring. “We are seeing the revitalization of an entire ecosystem. It is really uplifting,” said John Buchanan, a Squamish conservationist who voluntarily walks streams in the area to help count spawning salmon.

And this:

“This year, we had a massive spawn,” said Jack Cooley, who is co-chair of the society. “We’ve never seen anything like it. Herring were spawning everywhere.”

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Is there a more optimistic phrase than “herring spawning everywhere”? Well, probably, but this is still great news. The take-away, local environmentalists say, is to never give up on a river.