The Cascade Caused by Whale Killing

Over on Twitter, the always-great Ed Yong writes:

• The whales killed during the 20th century collectively weighed 2x more than all the wild mammals alive today. A new study reveals the enormous hole that their slaughter left in the ocean, and suggests a bold path for restoration.
  
  
• Pre-industrial whaling, whales ate 2x as much krill as exist today every year. Or 2x the global fisheries catch. Which was fine because their poop fertilized the same food webs that they gorged upon. When the whales were killed, those webs imploded.
  
  
• One possible but controversial solution is to add iron to former whaling grounds, jumpstarting food webs that the whales once fuelled themselves. This plan is essentially humans cosplaying as giant piles of shit, which we should be *amazing* at by now.

Read his terrific article on all this --- and more -- in The Atlantic:  The Enormous Hole That Whaling Left Behind.

One possible way to start to set things right: salt the southern oceans with iron to boost krill populations back to their pre-slaughter level.  

The slaughter of whales in the 19th and 20th centuries is a story beyond belief.  We invented exploding harpoons and even electrocuted harpoons.  After World War II, the Russians alone killed 180,000 whales in what has been described as "the most senseless environmental crime of the 20th Century."