A Scoping Review of Sanitary Survey Methodology for Shellfish Harvesting Areas Across Seven European Jurisdictions

Abstract

Sanitary surveys support the classification of shellfish harvesting areas and the design of microbiological monitoring programs under European shellfish hygiene legislation. These surveys identify sources of fecal contamination and assess the effect of environmental factors on shellfish water quality. This study presents a scoping review of 110 sanitary survey reports from seven European countries (Scotland, England, Wales, Ireland, France, Denmark and Portugal), covering the period 2007–2026. Reports were identified from websites of research organizations, regulatory agencies, and technical contractors responsible for sanitary survey preparation, and screened against inclusion criteria based on regulatory requirements and methodological detail. A structured data extraction framework based on the PRISMA-ScR extension for scoping reviews was used to harmonize survey components across reports. Extracted variables included catchment characterization, wastewater treatment and discharge reporting, meteorological and hydrodynamic assessment, shoreline survey implementation, justification of representative monitoring points, and design of monitoring plans. Substantial heterogeneity in report content and analytical approaches was observed. Rainfall was considered in all 110 reports, but formal statistical evaluation of relationships between rainfall and microbiological contamination was undertaken in 43/110 reports (39%). At least one statistically significant rainfall–microbiology relationship was explicitly reported in 36/110 reports (33%). Hydrodynamic modelling was used in 53/110 reports (48%), with substantial variation among jurisdictions. While all surveys identified potential sources of fecal contamination, the inclusion of quantitative indicators such as wastewater population equivalents, discharge characteristics and statistical rainfall analyses varied considerably. Hydrodynamic assessments ranged from descriptive tidal characterization to model-based dispersion analyses, and the justification of monitoring locations and harvesting area boundaries differed across reports. These results indicate that sanitary surveys are not methodologically standardized across the jurisdictions included in this review. Greater harmonization of reporting standards and environmental analysis could improve transparency and comparability in shellfish classification systems and overall shellfish hygiene.