Authorities have recorded 61 sharks in the East Sea off South Korea’s coast since the start of 2026. There were 19 in the same period of the previous year. South Korean broadcaster MBC reported the figures, citing the National Institute of Fisheries Science (NIFS).
The total covers different kinds of records, including catches and animals found dead in nets or on the coast. It therefore does not automatically prove that the East Sea’s shark population has tripled. It shows first of all that substantially more animals were documented this year.
Shortfin makos and blue sharks among the finds
According to the report, many of the recorded animals were large pelagic species. Shortfin makos (Isurus oxyrinchus) and blue sharks (Prionace glauca) were specifically named. A large shortfin mako was caught off Uljin in North Gyeongsang Province in July.
MBC also showed earlier examples: about three months before the report, a hammerhead shark was found dead in a net. In 2025, the carcass of a thresher shark had been found off Busan. These individual cases illustrate the range of records, but do not on their own establish a long-term population trend.
The East Sea is warming particularly quickly
The MBC report identifies the strong warming of the East Sea as a possible background factor. It says the water temperature there has risen by 2.04 degrees Celsius over roughly the past 50 years—about 2.7 times as fast as the global ocean average.
Higher temperatures can affect not only sharks directly, but also their prey. NIFS specialists suspect that warm-water species such as mackerel have shifted their distribution, making more food available to large sharks in the region. The temperature rise is reported to be particularly pronounced in summer.
A plausible explanation, but not yet proof of causation
For now, the link remains a working hypothesis. The number of documented sharks can also be influenced by fishing effort, reporting practices, observation conditions or short-term migrations. The two annual figures alone cannot show how much of the increase is actually due to warming.
The television report repeatedly describes the animals as dangerous or aggressive sharks, but this is not a uniform biological category. Species, size, habitat, season and the circumstances of each record are more useful for ecological interpretation than a broad danger label.
Fisheries institute plans ecological studies
NIFS therefore intends to investigate the development more systematically. Planned work includes analyses of species distribution, diet and possible reproduction in the East Sea. The goal is to determine whether the animals visit the region only seasonally or whether their use of the habitat is changing over the longer term.
Only longer time series collected with consistent methods can show whether 2026 is an outlier or part of a stable trend. The observations are an important signal for further research, but not yet evidence that the shark population is three times larger.
