It is usually saltwater crocodiles that force the closure of popular swimming areas in the Northern Territory.

But Darwin City Council has decided to close one in the Top End capital because of the danger posed by a large fish which recently bit a woman on the foot.

The woman suffered minor lacerations as a result of the incident, which occurred at Lake Alexander in the Darwin suburb of East Point.

"Instances where large fish are a problem in the lake are very rare, but when they occur we must act to ensure the safety of the community, " the council's chief executive, Brendan Dowd, said.

The lake will be closed on Wednesday and Thursday this week so that council officers can remove the large fish.

Mr Dowd says traps and long lines will be set and all efforts will be made to capture the fish alive so they can be released into the ocean.