Photo shows the bionic robot fish in the West Lake in Hangzhou, East China's Zhejiang province. [Photo/Hangzhou Public Security Bureau]

A pair of bionic robotic fish, designed to resemble carp and small sharks, has been deployed in West Lake in Hangzhou, East China's Zhejiang province, to assist in retrieving tourists' lost belongings and monitoring invasive species.

The robotic fish, developed by the West Lake scenic area public security bureau, measure approximately 60 to 70 centimeters in length. Their "eyes" are two underwater cameras, designed to address the limitations of manual retrieval.

Local police will deploy the robotic fish into the water for tourists who lose items in the lake. Operators set a search area via a remote controller, and an inertial navigation system inside the fish calculates the position of lost items in real time.

The visual sensors installed in the fish's head can identify items such as phones and wallets even in turbid water, locking onto objects buried in shallow silt with a localization error of no more than 10 centimeters.

The robotic fish can also assist in controlling invasive species, such as red-eared sliders, which have been increasingly released into the lake. Their visual sensors capture images for analysis, providing support where manual monitoring is difficult.

The robotic fish are expected to undergo trial operations in the core waters of West Lake before the National Day holiday and will subsequently be deployed across all key areas of the lake.