Originally, Ian believed that the so-called certain death danger must have originated from the Ironclad Shark's lair encountering some kind of labyrinthine situation, causing significant environmental changes—without mentioning anything else, just the localized heating near the nest would surely deal a heavy blow to the sharks that were sleeping and attempting to grow and transform. It wouldn't be strange for them to die.
After all, the entire ecosystem of the Southern Sea Labyrinth very likely revolved around abnormal mutations and high-energy catalysis caused by nuclear radiation leakage from the orbital accelerator… Given that, it wouldn't be odd for it to occasionally release heat either, especially with the recent situation of potential major changes in the ruins, it all seemed quite reasonable.
However, the reason for the Ironclad Sharks encountering danger turned out to be very simple.
—This place, someone is fishing!