A fishing net that lets fish escape initially sounds like a ridiculous idea. But when you discover that its purpose is to keep the fish you want, and lose the fish you don’t, thinks start to make sense.
The net is designed to make commercial fishing more sustainable by reducing the number of non-target and juvenile fish picked up by trawlers, many of which are returned to the sea dead.
To set up the system, special rings are first fitted to a regular net. Unlike normal holes in a net, the rings don’t close up during the trawling process, leaving a way out for the smaller fish. Inside the rim of these so-called Escape Rings are light rings, which act as a kind of ‘emergency exit’ sign for the fish.
“The devices fit into trawl nets and they cut down on the bycatch of juvenile fish and also the wrong species of fish,” Watson explained to the BBC.
“The rings fit into the ‘cod-end’ of the net – the part where all the fish are kept – and they basically exploit fish behaviour and their physical size to guide some to safety while keeping the other ones in.”
The light rings obtain energy from their own motion as they are dragged through the water, and activate automatically once they reach a certain depth. This means that once fitted, those working on the boat can pretty much forget about them.
Watson explained to the BBC that about 20 rings are needed per net, costing a total of around $790 (£500).
In the final stage of the competition, the Brit will face designers from 17 other countries, all hoping to win the James Dyson Award with their various design-based ideas. The winner will be announced in November.
Regardless of whether his net takes the top prize in the competition, Watson plans to commercialize his SafetyNet system in the near future.