PORTLAND, Maine — The federal government is changing some of the rules about how fishermen harvest tuna in an attempt to protect one of the species.

The National Marine Fisheries Service has said the rule change is designed to steer fishermen who catch yellowfin tuna and swordfish via longline away from bluefin tuna.

Globally, Atlantic bluefin tuna are listed as endangered by the International Union for Conservation of Nature. Domestically, the U.S. government considers the species to be overfished. Fishing boats sometimes catch them incidentally while targeting other commercial fish species.

The fisheries service said the new rule will modify the way the agency handles the distribution of quota transfers in the longline tuna fishery. The service said flexibility will improve fishing opportunities while limiting the number of bluefin tuna that are incidentally caught.

The rules will also assist with the goal of accounting for all bluefin tuna that do get caught, the service said.

The new rules go into effect Jan. 28.