In 2003, scientists targeted invasive fish in the Grand Canyon. By 2006, Rainbow Trout fell from 90% to less than 10% of the catch

For four consecutive years, scientists actively removed invasive fish species from the Colorado River. This strategic initiative led to a notable shift in the river's fish population, giving native fish a competitive advantage free from predation. Yet, persistent drought conditions complicated efforts to isolate the improvements directly linked to the removal process. The study underscored the complexities involved in discerning the impacts of human actions versus natural ecological changes.

Raccontata daeconomictimes.indiatimes.com