China claims foreign agencies used sensor-fitted marine animals to monitor its waters
China's Ministry of State Security has claimed that foreign intelligence agencies are using sensor-fitted marine animals to collect sensitive data in waters around China. In a post on WeChat, the ministry said an "invisible secret war" was under way at sea and alleged that "spy turtles" and "spy fish" had been found attached to sensors while swimming in Chinese waters. It said the devices were being used to gather underwater information and transmit it overseas.
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The ministry said the animals were collecting marine environment data including water temperature, salinity and ocean currents in real time. It said the information was being sent via satellite, but did not identify where the animals were found or which foreign agencies were involved. The post also alleged that foreign actors were using other devices to gather maritime data, including buoys fitted with meteorological sensor packages and a wave glider powered by wave motion and solar energy.
According to the ministry, the buoys were deployed by an overseas marine research institute and were capable of tracking the acoustic signatures of Chinese submarines in real time. It also said the wave glider was used to transmit military-related maritime environmental data and information on vessel activity. The claims were presented as a national security concern, with the ministry saying the collection of underwater maps posed a serious threat to China's security.
The allegations matter because they point to the growing overlap between marine research, surveillance technology and military intelligence. Underwater data such as salinity, currents and acoustic conditions can be relevant to submarine operations, naval movement and wider maritime monitoring. China regularly raises espionage concerns in nearby waters, including the South China Sea, the East China Sea and the Taiwan Strait, making such claims part of a broader security narrative.
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The ministry's post also placed the allegation in a wider context of maritime spying methods. It said the use of animals fitted with sensors was one of several new techniques being used by foreign agencies to collect information at sea. The claim follows previous reports elsewhere of animals being used in military or security roles, including trained dolphins deployed for harbour defence, although the Chinese ministry did not provide evidence linking its own allegations to any specific country or operation.
It remains unclear where the alleged animals were found, who fitted them with sensors, and whether any independent verification exists for the claims. The ministry did not name the foreign agencies or the overseas marine research institute it referred to. What to watch next is whether Chinese authorities provide further detail, whether any other government responds, and whether the allegations lead to new warnings about maritime surveillance in the region.
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