Decline of Predators at the Top of the Food Chain Modifies the Ecosystem

Reader Contribution by Emylisa Warrick
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From whales to lions, predators at the top of the food chain are declining with dire results for the ecosystem. A paper published recently in Science journal discusses the destruction of “apex consumers,” predators at the top of the food chain, by the hands of human activity and how the consequences include increased carbon in the atmosphere, damaging wildfires, and the spread of animal diseases to human beings.

The study was conducted by an international team of scientists in six countries. The research took place in a wide range of ecosystems from terrestrial to marine. Support for the study was provided by the National Science Foundation, the Institute for Ocean Conservation Science, and others.

Human activity that damages predator populations at the top of the food chain includes hunting, driving species away from livestock, and the fragmentation of ecosystems.

The following examples are cited in the study:

  • Industrial whaling has led to declining populations of plankton-eating great whales. There is carbon contained in the whales’ feces and whales deposit this carbon in the deep sea. The decline of the whale population has led to an increase of 105 million tons of carbon into the atmosphere.
  • The baboon population was amplified due to the destruction of lions in Africa. Baboons carried over intestinal parasites to human settlements nearby.
  • The reintroduction of wolves in Yellowstone National Park reduced deer and elk populations, allowing aspen and willow trees to recover.

Lead author James Estes, a marine ecologist at the University of California, Santa Cruz, states “[The top-down effects of apex consumers] have diverse and powerful effects on the ways ecosystems work, and the loss of these large animals has widespread implications.”

Large predator populations at the top of the food chain need time to recover. It’s essential to look at the small and big components leading up to the larger picture of ecological preservation and biodiversity. For more on this issue, see our recent article, Keystone Species: How Predators Create Abundance and Stability.

Emylisa Warrick is an Online Editorial Assistant at Ogden Publications, the parent company of MOTHER EARTH NEWS. Find her on .

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