From the New York Times Magazine: The current worldwide loss of biodiversity is popularly known as the sixth extinction: the sixth time in world history that a large number of species have disappeared in unusually rapid succession, caused this time not by asteroids or ice ages but by humans.
When we think about losing biodiversity, we tend to think of the last northern white rhinos protected by armed guards, of polar bears on dwindling ice floes
… But extinction is not the only tragedy through which we’re living. What about the species that still exist, but as a shadow of what they once were?
In The Once and Future World, journalist JB MacKinnon cites records from recent centuries that hint at what has only just been lost: “In the North Atlantic, a school of cod stalls a tall ship in mid-ocean; off Sydney, Australia, a ship’s captain sails from noon until sunset through pods of sperm whales as far as the eye can see ... Pacific pioneers complain to the authorities that splashing salmon threaten to swamp their canoes.”
There were reports of lions in the south of France, walruses at the mouth of the Thames, flocks of birds that took three days to fly overhead, as many as 100 blue whales in the Southern Ocean for every one that’s there now.
“These are not sights from some ancient age of fire and ice,” MacKinnon writes. “We are talking about things seen by human eyes, recalled in human memory.”