A century of commercial whale hunting has devastated whale populations around the globe, some to just 10% of their historic size. This animated map shows how different whale populations were systematically slaughtered between 1900 and 2011. But there's a bright spot: California's blue whales are doing great!

There are a few things that pop out. For one thing, the last twenty or so years has seen a dramatic reduction in whale hunting in most parts of the world, which is a good thing. Though, if we're going to be honest, that's at least probably in part because there are simply fewer whales to hunt. For another, those colored zones around Japan and Iceland just won't seem to disappear, even as recently as 2011. The extent of whaling in the Southern Oceans is just staggering when visualized like this.

The bright spot here is that the blue whale population of the coast of California seems to have returned to pre-1900 levels. But Andy Revkin, at the New York Times Dot Earth blog, puts that into perspective:

As the university news release noted, it's important to keep in mind that the California recovery is a tiny bright spot given that researchers estimate (from other work) that the 3,400 whales killed in that population from 1905 to 1971 pale beside the 346,000 harpooned in Antarctic waters in the same span.

The National Oceanic and Atmospheric Administration estimates that the Southern Hemisphere population was 175,000 before the whaling binge and is about 2,000 today.

Whales are long-lived creatures who reproduce slowly. It will probably take quite some time - and a concerted anti-whaling effort - before other populations bounce back to their historic levels. And that's assuming there's even enough food to sustain those populations in our changing oceans. Conservation science is an endless cycle of hope and despair.


Video: data from University of Washington researcher Cole C. Monnahan; images and sounds added by Revkin.