Tuesday February 20, 2024
Newsweek —
The rivers of the U.S. and other countries around the world are becoming more diverse and filling up with a wide range of invasive fish, but that may pose a threat to the “delicate balance” of native species, a study has found.
New research from the University of Sheffield with Illinois State University, the University of Tennessee and University of Washington found that there are more diverse species of fish emerging in rivers. At first, scientists thought this was because of improved water quality and ecosystems.
However, the research, published in Nature Ecology Evolution, points to a different explanation—an increase in invasive species. It uncovered a 13 percent increase in fish communities per decade, and a 7 percent rise in species diversity, but a 30 percent decrease in “riverine fish community similarity.”
The increase in river fish diversity may not be good news, the authors said. It could be threatening native fish populations and reflect that invasive species often thrive in ecosystems degraded as a result of human behavior.