Humans are putting the future of certain species at risk by killing animals that are the "wrong size and age," a new study has found.

A report by the Science journal said that the way humans are hunting and fishing is unsustainable and is counter to the principles of nature, as rather than killing smaller and weaker animals (as is typical of predators in the wild), we're instead focusing on killing the biggest, most mature specimens.

The issue with this is that many of the mature animals being killed are at their reproductive peak, and killing them could lead to significant ecological impacts and change the course of evolution.

The study found that humans are acting as a "super predator" who are killing up to 14 times more adult prey than other predators.

The rates are particularly high when it comes to carnivores killed by trophy hunters, as well as fish – a practice that is taking nature from "survival of the fittest to survival of the smallest," lead author Chris Darimont told the Associated Press.

He said that taking bigger fish or animals "has remarkable short-term benefits" in terms of food production, but poses serious long-term implications.

He cited an example of the collapse of the Atlantic cod, saying that over-fishing caused female cod to start reproducing at an earlier age as they weren't living long enough to reach their reproductive peak – when they can grow more than double the amount of eggs, AP reports.

The study said possible remedies could include "cultivating tolerance for carnivores," designing "catch-share" programs, and supporting "community leadership in fisheries."

It also suggests hunters and fishermen mimic nonhuman predators by focusing more on juveniles rather than the killing of full-sized adults, although it acknowledges that "cultural, economic and technological factors would make targeting juvenile prey challenging in many cases."

Darimont told AP that men have evolved to "like bigger trophies in hunting and fishing to impress others."