A city in South Korea seeks new ways to free a huge gray shark after it slips back into canal

SEOUL, South Korea -- A city in South Korea was trying Thursday to come up with a new way to free a huge dusky shark out of a narrow canal. Workers in the port city of Busan had herded the shark, nicknamed Bukangi, out of the canal the day before, after weeks of trial and error — only for it to swim right back in hours later.

Now Busan authorities and the country’s Oceans and Fisheries Ministry are determined to guide Bukangi back to open water, saying it is critical for the shark’s safety and health.

The unconventional rescue effort on Wednesday involved dozens of workers maneuvering a floating platform through the canal to push the 3-meter-long (9.8-foot) female shark out. After lingering in nearby waters for hours, the shark swam beneath an outer barrier net installed on the platform that night and reentered the waterway.

According to officials, Bukangi is now stuck between that net and a second one about 50 meters (55 yards) into the mouth of the canal, with on-site inspectors and rescuers debating ways to guide it back out as the shark circles the small patch of water.

Lee Gwang-seok, an official with the Oceans and Fisheries Ministry, said Bukangi was unlikely to slip past more barriers and move farther up the canal, considering the density of the nets and the narrow waterway in that section that leaves little room for the shark to squeeze through.

There were no signs that the shark had been feeding regularly during its monthlong stay in the canal, and falling water temperatures could pose additional health risks, officials say.

The local Busan authorities did not immediately say when a new rescue effort for Bukangi would proceed.

Marine scientists are perplexed as to why the shark is staying in the canal

Sharing the Korean name of Busan’s North Port, where it was first spotted in mid-September, Bukangi had become a major tourist attraction as it slowly circled the canal, its fins slicing through the water’s surface.

Busan officials, who made Bukangi a city mascot, say the shark attracted more than 1.7 million visitors to the canal, and hundreds of people lined up along the canal on Wednesday to watch the unusual rescue effort.

Marine scientists don’t have a clear answer as to why the shark entered the canal, or why it has stayed.

Its behavior may have something to do with Busan being one of Asia’s busiest ports — away from the ruckus, the narrow canal may appear to be a safe space, according to Kim Hyun-woo, a senior researcher at South Korea’s National Institute of Fisheries Science.

The North Port is a major hub for container and cruise traffic, possibly producing an intimidating environment for the shark. It’s also possible that the noise from vessels, bright lights and electric fields generated by nearby facilities and equipment have interfered with the shark’s senses, Kim said. While authorities have stressed the need to get Bukangi out to sea quickly, Kim said patience will be key, giving the shark time to adjust to the waters beyond the canal before venturing farther out.

“The shark has been staying inside the canal for an extended period, so I didn’t expect it to head straight out into the open water,” Kim said. “It would be best to give it about a week to leave on its own.”

A third attempt to free the shark was a success for just a few hours

Wednesday’s operation was the third attempt to free Bukangi, following failed efforts on Sept. 29 and Oct. 2 that involved boats spraying streams of water and nets placed across the narrow waterway.

Bukangi avoided the boats and swam over the nets. Dusky sharks can grow up to 4.2 meters (13.7 feet) long and live in tropical and temperate waters around the world, roaming long distances to find waters ranging between 18-26 degrees Celsius (64-79 degrees Fahrenheit) while feeding on fish and squid, according to Kim’s institute.

The species reproduces slowly, making it vulnerable to population declines, and is listed as endangered by the International Union for Conservation of Nature and Natural Resources.

Water temperatures in the Busan area were around 20 degrees Celsius (68 degrees Fahrenheit) on Thursday morning, according to official data.