Extended soak times could strengthen sustainability of UK whelk fishery

Extending the time that baited pots are left on the seabed could significantly improve size selection and reduce waste in the UK’s common whelk fishery, according to new research published in Reviews in Fish Biology and Fisheries.

The study, led by Moritz Eichert, a PhD student at the Lyell Centre for Earth and Marine Sciences at Heriot-Watt University, in collaboration with international partners, is the first to clearly demonstrate how the length of time whelk pots are left in the water influences the size of whelks caught.

Using experimental fishing trials, the researchers found that longer soak times allow undersized whelks to exit traps naturally on the seabed through escape gaps, while still retaining larger individuals that can be legally landed.

The results show an improvement in effectiveness as soak time increases. When pots were hauled after around 18 hours, a substantial proportion of undersized whelks remained trapped. By contrast, extending soak time to approximately 46 hours allowed escape gaps to function far more efficiently, with almost all undersized whelks exiting the gear before hauling.

The findings suggest that shorter soak times, often used to maximise fishing efficiency, may unintentionally limit the conservation benefits of existing technical measures.

With the UK responsible for a large share of global common whelk landings, the paper notes that incorporating soak time into discussions on best practice, management and sustainability assessments could offer a practical and low-cost opportunity to better protect juvenile whelks while supporting the long-term viability of the fishery.

Increasing soak time improves size selection and harvesting patterns in common whelk (Buccinum undatum) pot fisheries was published in Reviews in Fish Biology and Fisheries.