Humans are fishing and hunting animals that are the wrong size and age, in an unsustainable way that flies in the face of nature, a new study finds.
Long-held conservation policies and traditions that tell fishermen to throw back small fry and encourage hunters to bag only the biggest trophies often hurt species instead of helping them, according to the authors of a study released Thursday by the journal Science.
The study compared humans to other predators to see what they killed, looking at nearly 400 species in the oceans and on every continent except Antarctica. And while other animals tend to kill the young, small and weak, humans kill the more mature animals that are in their reproductive primes. It found humans killed up to 14 times more adults than other animal predators, with the biggest differences in prey seen in how humans fish.
Thanks to our tools and intelligence, humans now boast “rather unnatural, unusual predator behavior,” said study lead author Chris Darimont, a scientist at the University of Victoria in Canada. The method is “not considering the hand of Darwin.”
The ways humans hunt and fish “change the rules of the game” of evolution from survival of the fittest to survival of the smallest, Darimont said. Taking bigger fish or wildlife has “remarkable short-term benefits” — for example, it makes it easier to process for food. But long term, it’s a loser, Darimont said.
Renowned conservation expert Stuart Pimm of Duke Universit praised the study. “We ought to be harvesting animals that are about to die from other causes,” he said.
