This project aims to provide a method to coastal fishers wishing to augment their crustacean catches with high-value, low-impact scallops.
This work programme builds on the discovery that scallops can be attracted into crustacean pots using light (Enever et al 2022) and explores the factors that effect this behaviour.
Initially, scallop behaviour was observed in tanks with respect to trap design, light wavelength and flash rates. The most promising light and trap designs were then trialled at sea on fifty observed trips between August 2022 and March 2023. 2,766 pots (of various design and light configuration) were shot, hauled, and sampled onboard commercial fishing vessels operating from the ports of Whitby, Peel, Dartmouth, and St. Mawes.
Using the best combination of light colour, intensity, duty cycle, and trap design, we were able to improve the catch rate of scallops retained by the traps in the initial feasibility study by 500%. Average scallop retention across all trials was just under 2 scallops per pot per haul, with a maximum number of scallops recorded in a string averaging 26 scallops per pot.
Crab and lobster catches were reduced slightly (compared to the control pots) in the experimental pots optimised to catch scallops. However, a re-design of the “scallop eye” and subsequent tank testing has now resolved this issue, with no reduction in crab ingress or retention.
We are now in a position to propose equipping a pilot fleet with this innovative scallop potting method to ensure supply and to stimulate the development of a new market for this low-impact seafood product.
The findings of this work will be written up in full and published in the scientific press later in 2023.