Salmon have been swimming in Pacific Northwest waters for at least seven million years, as indicated by fossils of large saber-tooth salmon found in the area. During that time, they've been a key species in intricate, interconnected coastal ecosystems, bringing nitrogen and other nutrients from the ocean and up streams and rivers to spawning grounds, feeding whales, bears and eagles and fertilizing the magnificent coastal rainforests along the way. For as long as people have lived in the area, salmon have been an important food source and have helped shape cultural identities.

Watching grizzly bears catch and eat salmon as they swim upstream to spawn is an unforgettable experience. Many people love to view the wild drama. Some record it with photos or video. But a few want to kill the iconic animals -- not to eat, just to put their heads on a wall or coats on a floor.

Few places on our planet have been unaffected by humans. Satellite images taken from hundreds of kilometres above Earth reveal a world irrevocably changed by our land use over just the past few decades.

From Arctic tundra to primeval rainforest to arid desert, our natural world is being fragmented by ever-expanding towns and cities, roads, transmission lines and pipelines, and pockmarked by mines, pump jacks, flare stacks and other infrastructure used to drill, frack and strip-mine fossil fuels.