Setback in fight against invasive Asian carp

Should an artificial waterway in Chicago be closed to block two highly destructive fish from entering Lake Michigan and then the other four Great Lakes?

An invasive Asian carp leaps above a biologist trying to snag it at Big Muddy National Fish & Wildlife Refuge in Missouri. Asian carp, imported to clean fish ponds, have spread widely through the continent’s largest river system, and are poised to enter the Great Lakes. Those prongs create an electric field that causes the fish to rise to the surface.

On Feb. 27, the Supreme Court said ‘no’ when it declined to revisit an appeal by the State of Michigan, which wanted to compel closure of the Chicago Ship and Sanitary Canal. The canal, created to drain stormwater and wastewater from Chicago, could allow silver and bighead carp from the nearby Des Plaines River to enter Lake Michigan.

Since the two carp, native to Asia, escaped from fish ponds in the South in the 1970s, they have occupied much of the Mississippi River system, and have become extremely abundant in rivers near the Canal. Biologists, state agencies and the Great Lakes Commission warn that once the fish reach Lake Michigan, they will likely spread through the five lakes, then into the St. Lawrence River.