One of the world’s busiest harbors became the scene of a dramatic rescue operation Friday after a young humpback whale was spotted with fishing gear tangled around its tail.

Rescuers were first alerted to the 13-meter whale in Sydney Harbour on Thursday afternoon when volunteer rescue group ORRCA received a call on its rescue hotline.

Crews from the New South Wales large whale disentanglement team took up the chase and attached a GPS tracker to the whale, but the device fell off soon after.

The operation paused overnight when the sun went down, but the whale was spotted again in the harbor early Friday morning and the chase resumed.

Local media streamed live video from a helicopter circling overhead as the rescuers tried to get close enough to cut the gear loose. Video showed the whale’s dark silhouette beneath the water, as it popped up occasionally to thrash its tail.

“The challenge with that whale was that it had so much energy,” said disentanglement team leader Luke McSweeney. “It took quite a long time for us to tire it out so that we could get in and do that cut safely.”

Rescuers in rubber boats tried to slow the whale down by attaching orange floats, increasing its resistance through the water. Once they got close enough, they used specialized cutting equipment – blades attached to poles – to cut it free.

“Once it was cut free, it certainly took off free swimming, and really looked fantastic,” said Ben Khan, area manager for New South Wales Parks and Wildlife Service.

Humpback whales migrate past Sydney on a route known as the “humpback highway,” said wildlife scientist Vanessa Pirotta. Along the way, sometimes they get caught up in fishing gear.

“The disentanglement team have done an undoubtedly amazing job. It’s a very dangerous task and one that’s very unpredictable,” said Pirotta.

“Every single whale entanglement is different, and unfortunately, whale entanglement happens globally, but we tend to see it here in Australia annually when we have humpback whales in our waters migrating,” she said.

The whole operation took place in the middle of one of the main thoroughfares through Sydney Harbour, where ferries regularly cross from Circular Quay to Manly.

Authorities set up an exclusion zone, warning vessels to stay away, but there was no impact on cross-harbor commutes, according to government officials.

“We managed to do the whole operation without any disruption to passenger services and timetable ferries, which is an excellent outcome as well,” said Shane Davey from NSW Maritime.

After it was freed, the whale was seen swimming south, out of the harbor.

“Now that it has been disentangled, hopefully it continues south,” said Davey.