Loss of Large Predators Has Sweeping Impact on Ecosystems

The loss of top predators in terrestrial, freshwater, and marine environments has had a major impact on ecosystems worldwide, leading to changes in vegetation, more wildfires, a decline in water quality, and an increase in infectious diseases and invasive species, according to a study published in Science. “The loss of apex consumers is arguably humankind’s most pervasive influence on the natural world,” said the study, conducted by an international team of scientists. Their review cited numerous examples of how the loss of top predators cascades through ecosystems, creating significant disturbances. In Yellowstone National Park, the extirpation of wolves led to a flourishing elk population, which then overgrazed trees. Reductions in numbers of lions and leopards in parts of Africa has led to a rise of olive baboons, increasing contact with humans and the spread of intestinal parasites in humans and baboons. The decimation of sharks in the Chesapeake Bay has led to a proliferation of cow-nosed rays, which have over-consumed oysters. The authors said that to restore healthy ecosystems, land managers must also restore or reintroduce large predators.