This was the question that the Full Court of the Federal Court of Australia was asked to consider in Seafood Innovations Pty Ltd v Richard Bass Pty Ltd  FCAFC 83. Essentially, fish stunning is a process whereby a freshly caught fish is concussed prior to death in order to minimise stress and retain optimal taste and texture in the flesh of the fish.
In light of the recent media attention around the treatment of Australian cows in Indonesia, one might have thought becoming a pescetarian was a safe bet. This case provides an interesting elucidation of the sacrifices fish make in the interests of human consumption.
Historically, fish were stunned after they were caught by hitting the fish with a mallet just above the eyes to cause concussion. Mechanical devices were later developed where a piston was used to stun the fish, although these required the operator to force the fish through the device, which was slow and dangerous. The inventions claimed in the innovation patents the subject of this dispute (owned by Seafood Innovations) were mechanical fish stunning devices that incorporated a mechanism whereby fish are passed unidirectionally through the device by a "pivotally movable floor", which allows gravity to slide the stunned fish out of the device without human control. The Bass device, which was alleged to have infringed Seafood's patents, incorporated the "pivotally movable floor" but went a step further and included three additional flaps (to the left, right and above the fish) that operated simultaneously to release the fish from the device.
Seafood Innovations claimed that the Bass device infringed its patents as it incorporated the "pivotally movable floor" which was said to be the essential integer. Bass counter-claimed for invalidity on grounds of lack of fair basis and that the claims did not describe the invention.
At trial, Spender J held that the additional features of the Bass device went beyond Seafood's patents such they did not constitute infringement. In addition, the primary judge held that one of Seafood's patents was not fairly based and did not disclose the elements of the invention that were necessary to make it work.
Seafood appealed the decision, claiming that its patents were valid and infringed. On appeal, all three judges (Dowsett, Bennett and Greenwood JJ) allowed the appeal finding the patents valid and that Bass had infringed.
In the leading judgment, Bennett J held that the patents did not limit the passage of fish through the device only by movement of the floor (as a matter of construction), thus the fact that the Bass device utilised additional integers did not avoid infringement. Bennett J also held (with the other judges agreeing) that the claims were fairly based as "a narrow embodiment of a broad claim does not render the claim invalid for lack of fair basis".
We will wait to see whether Bass seeks special leave to appeal to the High Court - and as for your own views about these sorts of techniques on fish, we'll let you make up your own mind!