The appearance of a large shark at a waterfront park in Busan's North Port has drawn attention to how climate change is altering South Korea's marine ecosystem. Experts say rising sea temperatures are expanding the range of species that prefer warmer waters, drawing large predators such as sharks toward the coast in pursuit of prey.
A shark estimated at more than 3 meters long appeared for a fifth consecutive day on Sept. 22 in a waterway at the North Port waterfront park in Busan. The sighting of such a large shark in an urban waterway connected to the sea has continued to draw crowds of onlookers.
Experts agree the sighting is difficult to dismiss as a chance event. They describe it as the result of changes in marine habitats and food chains brought on by rising sea temperatures. In waters around the Korean Peninsula, warm-current species once found mainly in southern seas are gradually moving northward. As the distribution of fish species shifts, so do the migration routes of predators that feed on them.
Choi Yoon, an honorary professor of marine biology at Kunsan National University and a shark specialist, linked the recent appearances of large sharks along the Korean coast to rising sea temperatures. "This is a result of higher sea temperatures, and large sharks like this are expected to keep appearing," the professor said.
Warming seas driven by climate change do more than raise water temperatures. They can reshape the structure of entire marine ecosystems by altering fish spawning seasons, habitats and the distribution of prey organisms. When water temperatures change, spawning seasons for some species shift earlier or later. That can affect the growth and survival of juvenile fish, potentially leading to changes in populations.
Still, analysts caution against attributing the sighting to climate change alone. "Sharks have been appearing frequently along the East Coast for several years, and this is a phenomenon driven by a combination of factors, including currents, the distribution of prey and the movement patterns of individual animals," one expert said. "What is clear is that a long-term rise in sea temperatures is one of the factors raising the likelihood of sharks appearing along Korea's coast."
