When fish are processed in trawlers at sea, the animals' heads, guts and skeletons all just go overboard. It's a lot of waste, and Norway's SINTEF research group is doing something about it. Working with commercial fishing company Nordic Wildfish, it's developed a system that puts everything but the bones to use.
The prototype system has been installed onboard an existing trawler, and starts by using a hydrolysis process to separate the bones from the rest of the fish waste – hydrolysis is the breakdown of a compound due to a reaction with water.
After the bones are discarded, what's left is described as a "soup" to which enzymes are added. The addition of those enzymes allows oils, proteins and amino acids to be extracted, which could subsequently find use in animal feed or even human food.