During the weekend, I got into a conversation with one of my older brother in laws and he started telling me all sorts of things that happened when he was still living there. The conversation went around to the subject of fishing.
He described a way of catching prawns called merigis. At that time I could not imagine it but he described as something that you go around in a boat making a noise using an instrument called rigis. Apparently the prawns could not stand the sound and out they will come and jumped into the boat! Your boat has to be appropriately fitted to catch the flying prawns.
I found a photograph of 'merigis' but I am still not sure what equipment 'rigis' is that can make a sound so terrifying to the prawns. More of this in the future.