Scottish Shellfish Farm Production Survey 2025

Spat settlement

Following discussions between the Association of Scottish Shellfish Growers and the Marine Directorate, a spat collection question was introduced to the 2013 survey. It focused on common mussel spat collection and asked whether a site was used for spat collection and, if so, whether spat settlement was sufficient for production purposes.

Responses were received from 219 (100%) of the sites authorised for common mussel production in 2025. One hundred and twenty-seven (58%) of these were spat collection sites, 112 (88%) of which reported that they had sufficient spat settlement for production purposes. Insufficient spat settlement on sites may require movement of common mussel to that site which increases the risk of introduction or spread of diseases.

Number of sites.

The chart shows trends in the number of spat collection sites on common mussel farms and whether the quantity of spat collected is sufficient to meet farm requirements. The green dashed line represents the number of spat collection sites, and the solid dark grey line represents the number of sites reporting sufficient spat. Figures represent the number of sites each year.

Data Source: Scottish Shellfish Farm Production Survey 2025, Supplementary Tables, Table 5.