Tropical fish captured off the coast of Ulsan, flowing into the East Sea via warm currents

Recently, cases of various marine fish and tropical fish being discovered in Korean waters are increasing. According to a video from the YouTube channel 'Jeongbreu', this is because warm water temperatures in the surface layer of the eastern Philippines are being carried by trade winds near the equator, passing through Japan and flowing into Korea's East Sea coast, including Jeju Island, Busan, Ulsan, and the East Sea. This stream of water is as wide as 50–100 km, and it appears that large fish are also crossing over with it.

Various types of marine fish discovered near the inner harbor wall in Ulsan

The cast in the video conducted collection activities near an inner harbor wall at a pier in Ulsan and identified various fish species. Including colorful tropical fish attached to the pier wall, various creatures such as ant snails (a type of sea snail), starfish, and millipedes within the brittle star genus were captured. Additionally, various organisms such as venomous sea slugs, venomous spinefoot, and what appears to be an adult-sized damselfish were observed.

From porcupinefish to butterflyfish, the changing fish composition of the East Sea coast

During the collection process, porcupinefish, gobies, wrasses, damselfish, and striped red sea bream appeared in succession. In particular, the cast demonstrated the diversity of fish species caught in Korean waters by discovering porcupinefish and butterflyfish. In the video, two types of butterflyfish, porcupinefish, and creatures with the characteristic of attaching seaweed or shells to their bodies were identified, and native fish such as sandfish, Japanese jack mackerel, and red sea bream were also observed.

The phenomenon of tropical fish inflow due to ocean current movement

Explaining the phenomenon of tropical fish flowing in along the warm stream of water, the cast also mentioned recent cases where blue-ringed octopus, tuna, and whale sharks have been discovered in Korea. Subscribers participating in the video shared their experiences of directly collecting various fish species, from butterflyfish, in the inner harbors around Busan and Ulsan. The cast mentioned the difficulty of daytime collection and explained the characteristics of nighttime activities, where collecting marine fish is easier.