A new study says sport fish have declined significantly in portions of the Upper Mississippi River infested with Asian carp.
The study's lead author says it's among the first to establish a solid link between the presence of invasive carp and a drop-off of native species.
It found that numbers of sport fish such as yellow perch and bluegill fell between 1994 and 2013 in three locations infested with silver carp.
Meanwhile, sport fish increased in other places farther upstream that the carp hadn't reached.
The paper says Asian carp are gobbling up plankton that sport fish need for survival when young.
Fish biologist John Chick says the report illustrates the urgency of preventing the carp from moving into other sections of the Mississippi and the Great Lakes.
