Two Florida fishermen are suing federal officials over a new regulation advanced by the National Marine Fisheries Service (NMFS) that cuts the catch limit for a species of reef fish, the gag grouper, by 80% in the Gulf of Mexico.

Dominick Russo of Sarasota and James Russo of Tampa filed the lawsuit last month in the Southern District of Alabama, arguing that the new rule, known as Amendment 56, has had a calamitous impact on the pair’s business, FCC Seafood.

The plaintiffs, who are represented by the Pacific Legal Foundation, argue in their legal complaint that the NMFS can only issue a final rule that has been properly approved by a policymaking panel called the Gulf of Mexico Fishery Management Council.