News

The finger of blame for the world’s woes doesn’t very often come to rest over a big pile of whale poop, but new research published in the Proceedings of the National Academy of Sciences claims that our planetary nutrient recycling system is severely damaged—and extinctions and huge declines in big eaters like whales are the reason.

Massive ancient whales—and other megafauna—once transported nutrients from the ocean depths and spread them around the oceans to shallower waters where they could be recycled. But according to the new research, nutrient transport via this mechanism is just five percent of historical figures, after humans’ relentless hunting of large whales has reduced populations to a fraction of what they once were—perhaps as low as one percent of their pre-whaling levels. The research team found that the ability of whales and other marine mammals to transport phosphorous has dropped some 77 percent compared to the time before hunting began.

The situation is similar when it comes to moving nutrients from the sea to the land, such as fish being plucked from the ocean by seabirds and ending up as poop at nesting sites, or when salmon swim upstream and die, their rotting bodies being absorbed into the terrestrial ecosystem. With the collapse of fisheries and the attendant drop in seabird numbers, this nutrient-recycling route has been all but choked off. The study found phosphorous movement via these mechanisms down an incredible 96 percent.

One of the study’s researchers, Joe Roman, a whale expert at the University of Vermont, points out that recovery is possible, despite the grim figures. “We can imagine a world,” he says, “with relatively abundant whale populations again.”

Read more here.