British scientists, explicitly, researchers at University of Essex, plan to put a lot of robot fish into the sea off north Spain to identify pollution.
Using Wi-Fi technology, data collected can be broadcast to the port's main center.
The battery on every fish can last about 8 hours and alike to the Roomba vacuum cleaning robots, they are smart enough to go back to a "charging hub" to get recharged when battery runs low.
The cost for making one of these robot fish is around L20,000 (approximately $29,000), so it is surely not low-priced.