Fish farming is under attack from environmentalists who claim that it pollutes bays and inlets and spreads infectious diseases like salmon anaemia. The main problem is that cages used in most fish farms are fixed in place, which concentrates fish waste and uneaten food on the sea floor. Clifford Goudey, a researcher at MIT, has invented a fish pen propelled by robotic engines, which will allow fish farmers to deploy their pens in a wider area and along natural fish migration routes. Goudey has patented a number of fishing-related inventions, including a mobile ring fish pen. (US5617813)

Patents related to floating fish farms are classified in ECLA A01K61/00F.