Overview
- China’s Ministry of State Security issued a public advisory in mid-June urging fishermen, researchers and sailors to report suspicious marine devices and animals to authorities.
- The advisory said unnamed foreign intelligence actors have used sensor‑fitted turtles and fish, drifting buoys, solar‑powered wave gliders, and shipboard electronic kits to collect water temperature, salinity, currents, seabed maps and vessel activity.
- MSS framed the collection as a national security risk because oceanographic and acoustic data can help map coastal waters and identify submarine signatures.
- The ministry did not name any foreign state and the claims have not been independently verified in public, while news reports note similar historical cases but stop short of confirming the new technical evidence.
- The warning builds on a long Chinese effort to crowdsource detection — including cash rewards for turned‑in devices since 2018 — and could heighten coastal vigilance, surveillance operations and diplomatic tensions in the South China Sea.