‘Bukkangi,’ which had been staying in the artificial waterway at Busan North Port’s waterfront park, has been finally confirmed as a blacktip shark.
Although the possibility that it was a sandbar shark was initially raised, a decisive difference in physical features was identified in close-up footage.
With the species identification changed, the water temperature preferred by Bukkangi and the issue of its movement to the open sea have also become more important.
3-Line Summary
1. Bukkangi is a blacktip shark, not a sandbar shark.
2. A ridge between its two dorsal fins provided the clue.
3. A rescue plan has not yet been finalized.
The Ridge Between the Two Dorsal Fins Distinguished the Species
The National Institute of Fisheries Science announced on October 6 that it had identified Bukkangi, which has been staying long-term in the artificial waterway at Busan North Port’s waterfront park, as a blacktip shark. Bukkangi has been staying there since 18 of last month.
It was initially presumed to be either a sandbar shark or a blacktip shark in the genus *Carcharhinus*, based on its appearance. The two species are so similar that they are difficult to distinguish with the naked eye. However, analysis of close-up footage filmed beside the waterway confirmed a distinct ridge between the first and second dorsal fins. This ridge is an external characteristic of blacktip sharks and is explained as being absent in sandbar sharks.
Blacktip sharks have broad, rounded snouts, triangular upper-jaw teeth, and well-developed serrations. Bukkangi was identified as a female approximately 3m long. Blacktip sharks are approximately 70~100㎝ at birth and can grow to a maximum of 4.2m.
Water Temperature Became More Important After the Blacktip Shark Identification
Blacktip sharks are distributed in coastal and offshore waters in tropical, subtropical, and temperate seas, including waters around Korea, and mainly prefer water temperatures of 18~26 degrees. They are also a species that migrates long distances in response to changes in water temperature. On the International Union for Conservation of Nature (IUCN) Red List, they are classified as Endangered (EN) because of population declines.
According to a report by the Munhwa Ilbo, the water temperature at Busan Port was approximately 23 degrees, which at the time was within the range preferred by blacktip sharks. However, the report also conveyed an explanation from a research officer at the National Institute of Fisheries Science that the environment would not be suitable if the water temperature fell below 18 degrees. Because blacktip sharks prefer relatively warmer water than sandbar sharks, the question of whether Bukkangi could reach the open sea before the water temperature dropped began receiving greater attention.
In Korea, blacktip sharks and sandbar sharks were once considered the same species, but in 2019 blacktip sharks were reported to academia as a species not previously recorded in Korea. Since then, their appearances have been confirmed in waters near the southern coast, Samcheok, Sinan, Jeju, and Busan, among other areas. However, because past records mixed the two species, their distribution and scale of occurrence in Korea remain unclear.
After Two Attempts to Guide It Out, Authorities Are Waiting for It to Leave Naturally
Bukkangi remains in the waterway even after two attempts to guide it to the open sea. On the 3rd, the netting was removed to secure a passage toward the sea outside.
The National Institute of Fisheries Science plans to continue monitoring Bukkangi’s swimming behavior and health condition and to respond with Busan City and other relevant agencies if any abnormal signs emerge. Busan City said it was reviewing rescue measures but that no clear additional rescue method had yet been decided. It explained that no clear abnormalities had currently been detected in Bukkangi’s swimming condition.
References
Tags #BlacktipShark #Bukkangi #BusanNorthPort #BusanWaterfrontPark #Shark #SandbarShark #NationalInstituteOfFisheriesScience #MarineEcology #EndangeredSpecies #IUCN #BusanPort #SharkRescue