South Korean officials on Wednesday failed to guide a large shark back to the open sea after spending hours trying to rescue it from a canal in the port city of Busan, where it has been stranded for more than a month.

Rescue workers used a floating platform to steer the 3-metre-long female dusky shark, nicknamed Bukangi after the Korean name for Busan’s North Port, through the narrow waterway. However, by evening, the shark remained near the canal’s mouth instead of swimming out to sea.

The shark was first spotted in mid-September and soon became a popular attraction, drawing visitors as it swam in circles with its fins visible above the water.

According to city officials, Bukangi attracted more than 1.6 million visitors to the canal. The city also adopted the shark as a mascot. However, authorities struggled for weeks to find an effective way to guide it back to the open sea.

Wednesday’s rescue operation was the third attempt to free the shark. Earlier efforts on Sept 29 and Oct 2 failed despite the use of boats spraying water and nets stretched across the narrow canal. The shark evaded the boats and swam over the nets.

Experts have expressed concern over the animal’s health, noting that it had shown no signs of feeding during its 34-day stay in the canal. The declining water temperature has also raised concerns about its condition.

During Wednesday’s operation, workers carefully manoeuvred a large floating platform through the canal to push the shark towards the sea. Those on the platform used oars to turn it back whenever it approached, while dozens of workers on both banks pulled ropes to move the structure forward. Hundreds of spectators gathered along the canal to watch the unusual rescue effort.

The team managed to move the platform about one kilometre towards the canal’s mouth and installed additional nets to prevent the shark from swimming back into the waterway. However, camera and drone footage showed Bukangi swimming near the platform and nets for hours without heading out to sea.

“During Bukangi’s 34 days in North Port, the shark became a friend to the entire country and a symbol of Busan, the nation’s maritime capital. It’s heartbreaking to say goodbye,” Busan Mayor Chun Jae-soo wrote in a Facebook post.

He said authorities would continue doing everything possible to ensure the shark’s safe return to its natural habitat.