Define “Beneficial”, Define "Harmful"

Dave Levitan, writing for Conservation:

grafvision - shutterstock.com

grafvision - shutterstock.com

When we discuss invasive Asian carp, we’re usually just talking about a few specific species of carp, the silver, black, and the bighead. This is with good reason—in some parts of the Mississippi and Illinois Rivers those fish now make up 97 percent of the total biomass, with no predators around to hold them back. The grass carp, meanwhile, though found in all of the Great Lakes and plenty of other places, was actually introduced—theoretically, this was done quite carefully—and has not been considered a nuisance species at all. But new research suggests that even those invasives we think of as beneficial, often aren’t.

You will find only what values you bring in.