Federal regulators are imposing emergency fishing restrictions in response to plummeting cod stocks in the Gulf of Maine.

The measures, which will go into effect on Thursday, will effectively make it impossible for commercial fishermen to target cod, put strict limits on the amount of cod that can be caught as bycatch, and prohibit recreational fishermen from possessing cod.

Scientists say that restrictions are necessary because the cod population in the Gulf of Maine is at a record low.

“This is a stock that is in free fall,” said NOAA Fisheries Regional Administrator John Bullard at a press conference in Gloucester. “I can’t overstate the difficulty of the task before us.”

The federal government is taking this step now to prevent closing the entire fishery, which is what happened in Newfoundland in 1992 when the cod stocks collapsed on the Grand Banks, Bullard said.

The restrictions are for the current fishing season and will be effective until May 12.

The New England Fishery Management Council will meet next week in Newport, Rhode Island, to make recommendations about the 2015 fishing season.

Bullard said that the total allowable catch for cod in 2015 will be between 200 metric tons and 386 metric tons, down from the 1,550 metric towns that had been allowed for this year, about half of which has already been caught.