A large shark has become an unlikely tourist attraction after getting trapped in a narrow city canal in South Korea for more than a week.

More than 600,000 people are estimated to have visited a waterfront park in the southern port city of Busan since the 3.5-metre shark – nicknamed Bukang-i after the name of Busan’s North Port – was first spotted in its waterway on 18 September.

Experts believe it to be a bronze whaler shark that followed prey from the sea into the canal and could not find its way out.

The coastguard in the city about 200 miles (325km) south-east of Seoul tried to drive it out on the day it appeared but suspended the operation six hours later, on the advice of scientists who warned that forcing the animal could harm it or make it aggressive.

On Tuesday morning coastguard boats sprayed jets of water behind the shark to push it towards the canal’s mouth, a method officials said was modelled on the rescue of a great white shark that became trapped in shallow water off Massachusetts in 2004.

The first attempt failed, after the shark slipped past the boats and swam back into the canal, the Herald Business reported. The national institute of fisheries science said the shark was stable, but officials said its ability to feed and move was restricted, which could weaken it the longer it stayed. On Tuesday afternoon the operation was suspended again because the shark wouldn’t leave the waterway.

People viewing the shark in a Busan canal amid rescue efforts. Photograph: 이승재/YNA

Sharks are not unknown in South Korean waters. The fisheries institute recorded 46 large sharks off the east coast in the first half of this year, nearly four times as many as a year earlier, which it attributed to warmer seas and more of the fish that are the sharks’ prey.

The North Port Waterfront Park, which usually draws about 2,000 people a day on holidays, recorded 607,000 visits between 19 and 28 September, according to the city.

On Tuesday Kim Jung-sook, 62, came to say goodbye to the shark, telling the Maeil Shinmun newspaper: “I’ve grown attached to it after seeing it here for a few days … I feel a bit sad.”

Busan’s mayor, Chun Jae-soo, is a fan too. “It really has star quality. It comes up every five to 10 minutes,” he told CBS radio. “It’s just so pretty.”

The city has named the shark an honorary publicity ambassador, giving it the title “Shafluencer”, after 91% of respondents to a city Instagram poll backed the idea. Boogi, the city’s mascot, is to accept the certificate on its behalf.

Lee Do-yoon, eight, who came with his father to see it off, was not worried that it appeared to be time to see it off. “It’s OK,” he said. “Bukang-i is going to meet its friends.”