We nearly hunted blue whales to extinction. Now they're bouncing back.
It's easy to get pessimistic about the state of the oceans. Coral reefs are dying. Various fish species are getting wiped out by overfishing. Jellyfish are taking over. But not all news is bad news. A recent study published in Marine Mammal Science found that blue whale populations off the coast of California have almost entirely rebounded after being nearly hunted to extinction in the 20th century. (Many thanks to Andrew Revkin for pointing out this study.)