This project will investigate the potential to establish a new, commercially viable fishery that harvests Cold Water Prawn (Pandalus borealis) using illuminated traps.
On the back of anecdotal observations recorded by fishermen, this study tested whether LED lights could be used to catch commercial quantities of red and brown shrimp in modified creels in coastal waters off the West Coast of Scotland.
A total of twelve observed trips were sampled on both inshore, shallow grounds (targeting brown shrimp) and deeper offshore grounds targeting red shrimp. Catch data on species retained inside illuminated and non-illuminated pots for each design were recorded. A total of 16,000 individuals across 41 species were counted of measured.
Red shrimps were attracted into illuminated creels (n=2,641) compared to non-illuminated creels (n=574) but not in commercially viable quantities during these trials. Mean numbers of red shrimp per illuminated pot were 7.33 red shrimp across all hauls. The maximum number of red shrimps caught in a string of shrimp tubes was 789 (52.6 shrimp per pot) suggesting that on the right ground, there could be the potential for a viable fishery. Brown shrimps were not attracted to illuminated creels and catches of Norway lobster were reduced in illuminated traps compared to non-illuminated traps by 48%.
Gadoid fish (primarily poor cod but haddock and Atlantic Cod too) were also attracted inside illuminated traps (3,529 fish) compared to non-illuminated traps (n=671 fish). Stomach content analysis of the gadoid fish caught in the illuminated traps revealed that they had been feeding on the red shrimp attracted by the light. So whilst shrimp numbers retained in these traps appeared low, they had actually been consumed by the large numbers of predatory fish. This finding gives rise to the potential use of light (over bait) in traps targeting gadoid fish.