NMFS is implementing regulations consistent with Framework Adjustment 9 to the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan. This action will further enhance catch monitoring and address discarding catch before it has been sampled by observers (known as slippage) in the Atlantic mackerel fishery. Framework 9 implements slippage consequence measures, and a requirement that slippage events be reported via the vessel monitoring system. For allowable slippage events, due to safety, mechanical failure, or excess catch of spiny dogfish, vessels must move 15 nm (27.8 km) from the location of the slippage event. For non-allowable slippage events, due to reasons other than those listed previously, vessels must terminate their fishing trip. Slippage events have the potential to substantially affect analysis or extrapolations of incidental catch, including river herring and shad, and these measures are designed to address this issue.