Matt McIntosh | The Narwhal

The Great Lakes system system is no stranger to invasive species, but grass carp could upend the Great Lakes' ecology, as well as the operations of some of the world’s most significant freshwater commercial fisheries. So far, the Great Lakes have successfully held grass carp at bay. Those involved in managing the grass carp — not to mention the fishermen who rely on the abundance of native fish — can only hope that success is sustainable.