Missing 'Bukangi-ya' for Days... Falling Water Temperatures Likely a Factor

Observations suggest that falling water temperatures may be contributing to the disappearance of "Bukangi," a shark that spent more than a month in the artificial waterway of the Busan North Port Waterfront Park before moving outside, as it has not been spotted for several days.

According to relevant authorities, Bukangi has not been captured on the National Institute of Fisheries Science's monitoring equipment from the 27th until today (the 31st), its fifth day out of sight.

The fisheries institute suspended its regular on-site inspections starting yesterday, shifting its monitoring approach to dispatching personnel to the scene only upon receiving citizen reports, though no reports have been filed yet.

Experts believe that the drop in water temperatures in the waters off North Port has influenced changes in Bukangi's behavior.

When Bukangi was first sighted in the waterfront park waterway on September 18, the surface water temperature in the waters off North Port was around 25°C (77°F), but as the weather turned colder, it dropped below 20°C (68°F) for the first time on the 28th.

Experts explain that the optimal water temperature for the habitat of the blacktip shark, to which Bukangi belongs, is between 18°C and 26°C (64°F to 79°F).

The waters off North Port are currently close to the lower limit of the optimal temperature range, and are expected to drop to 15°C (59°F) around mid-November.

As the surface water temperature falls, Bukangi may have moved down to the relatively warmer deep sea.

Choi Yoon, professor emeritus in the Department of Marine Biology at Kunsan National University, said, "Due to the dropping water temperatures, Bukangi likely spends its time diving in deeper areas and surfaces less frequently, making it less visible to people."

After leaving the waterway and being spotted at Pier 1, Bukangi appeared in the waters off the International Passenger Terminal pier, located about 2 kilometers away, starting on the 24th, before disappearing on the 27th.

Considering Bukangi's movement routes and patterns, some observations suggest it may have traveled as far as the waters off Pier 7.

Professor Choi forecasted, "Bukangi may currently be in the waters off Pier 7 or may have headed out from North Port to the open sea, and it will likely be difficult for people to spot it from now on."

While it showed signs of health issues in the narrow and shallow waterway, such as wounds found across its body, Bukangi's health condition outside the waterway is presumed to be sound.

This is because the open sea outside the waterway provides a much better environment for sharks to hunt, even though the waterway was also inhabited by fish like mullet that could serve as prey.

During the period it stayed in the waterway, Bukangi was not captured engaging in feeding activities.

Professor Choi stated, "Around the time it moved out of the waterway, Bukangi's health condition was very poor. It will likely recover its health in the open sea and head out to the outer ocean via Busan Bay."

Bukangi, which was first sighted in the waterfront park waterway on September 18, moved out of the waterway on the 21st of this month—33 days later—following guidance operations by authorities and has since frequented the waters off North Port.

(Photo: Yonhap News)
※ Please note: This article was translated by AI and may contain errors.