Illinois officials struck quickly this Shark Week.  

Hours after policy advocate Nick Magrisso blogged on the National Resources Defense Council website about finding illegal shark fin soup on the menu of a Chinatown restaurant, conservation officers were at the restaurant door Tuesday.

Following “a tip” the officers of the Illinois Department of Natural Resources visited MingHin Cuisine restaurant where they found shark fin soup on the menu and a suspected shark fin on display.  

After confiscating the fin and confirming, with experts at the Field Museum, that the shark fin was real, officials issued a citation and $120 fine, the IDNR said.  

A popular Chinese soup ingredient (which can cost $80 per serving), shark fin became illegal to own, serve or trade on Jan. 1 of this year (although previously owned fins could be used until last month) as part of a law that made Illinois the first non-Pacific state to enact such legislation.

“The new law is designed to help end the killing of sharks for their fins and prevent the collapse of shark populations worldwide,” the IDNR said in a statement. “Frequently, after a shark’s fins are cut off for sale or trade, the shark is thrown back into the ocean alive, where it bleeds to death or drowns.”

Department spokesman Chris McCloud said the restaurant owner told officers he was aware of the law but that he had forgotten to remove the dish from his menu.  The presence of the fin on display paired with the menu listing, however,  sealed the citation, McCloud said.

MingHin Cuisine manager Joyce Li said Friday that the dish is no longer on their paper or online menus and that the confiscated fin “was not real. It was plastic and just for display.”  

This week the NRDC called out for a “fin-free Shark Week”  in Chicago.

“The near universal support for Illinois’ shark fin ban shows that the social license for dishes featuring the ingredient is running out,” said the Council’s Josh Mogerman. The initiative, he said, ”is intended to remind Chicago’s restaurants about the new state law and update their menus, as shark fin dishes do still appear on many menus in town,” according to NRDC’s perusal of online sites.

So will IDNR officers also be combing online menus in search of their next targets? McCloud is not so sure

“In this case we were given a tip,,” he said. “But there are many things that our conservation police have to do to protect the public safety and so we have to do the best with what we have.”

And we have to ask: Did the swift enforcement have anything to do with this being The Discovery Channel’s official Shark Week?

“Shark Week is very popular with me,” McCloud said. “But this was an absolute coincidence.”

Monica Eng is a producer for WBEZ. Follow her @monicaeng