Quantification of biosecurity measures in Mediterranean European seabass and gilthead sea bream farms

In the Mediterranean region, aquaculture drives economic growth and food supply through the production of seabass and sea bream. However, the region faces disease risks attributable to aquaculture intensification. Biosecurity is crucial for maintaining fish health and sustaining the aquaculture industry. This study adopted a novel risk-based scoring tool, originally developed for terrestrial animals, to benchmark biosecurity levels in seabass and sea bream. The tool considers all relevant aspects of aquaculture biosecurity, subdivided into external and internal biosecurity, with an accompanying questionnaire subjected to expert scoring. Land-based hatcheries and pre-growing facilities exhibited higher preventative measures, achieving overall biosecurity scores of 73.0 % and 75.0 %, respectively. These scores stem from stringent external and internal preventative measures, contrasting with lower overall biosecurity scores in land-based on-growing (50.0 %) and sea-based on-growing (59.0 %) facilities. Maintaining biosecurity during on-growing phases seems demanding due to uncontrolled interactions with the seawater environment and potential water quality issues. This benchmarking tool allows farmers to audit their biosecurity programs and pinpoint areas for improvement. These include vaccination, establishing biosecurity programs and keeping records, given the low scores across farm types. Improving vaccination practices, enhancing record keeping for traceability, and implementing robust biosecurity programs are crucial for improvement. Ultimately, the study emphasizes the need for tailored measures that foster synergy between external and internal components and enhance overall biosecurity in Mediterranean aquaculture. • First benchmarking tool developed to quantify biosecurity in food fish. • Land-based hatcheries and pre-growing facilities show higher internal and external biosecurity levels. • Farm location influences external biosecurity and must be optimized through effective spatial planning. • On-growing facilities face biosecurity challenges due to uncontrolled seawater exposure. • Robust biosecurity program, vaccination and record keeping for traceability are critical to enhance internal biosecurity.