Aquaculture Africa 2024

November 19 - 22, 2024

Hammamet, Tunisia

ENSURING THE SAFETY AND QUALITY OF FARMED SHELLFISH THROUGH BIOTOXIN MONITORING IN TUNISIAN AQUACULTURE PRODUCTS

*Nadia Besbes a* Amel Dhib a Brahim Aoun Nabli a Lotfi Monser b & Saloua Sadoka

 

aLaboratory of Blue Biotechnology and Aquatic Bioproducts (B3Aqua), Institut National des Sciences et Technologies de la Mer (INSTM). Carthage University, Tunisia.

bEcoChimie Laboratory, Department of Chemical and Biological Engineering, National Institute of Applied Sciences and Technology (INSAT), Carthage University, Tunisia.

 

*nadia.besbes@instm.rnrt.tn;

 



The safety and quality of farmed shellfish are vital for public health, especially in aquaculture, where filter-feeding shellfish, are prone to accumulating harmful biotoxins. These natural toxins, produced by harmful algal blooms, can concentrate in shellfish, posing serious health risks when consumed. The Food and Agriculture Organization (FAO) categorizes marine biotoxins into four main groups: paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP), and azaspiracid shellfish poisoning (AZP). Many countries including Tunisia, enforce rigorous monitoring programs to prevent the sale of shellfish products contaminated beyond safe levels.

In response to these needs, we have developed and validated precise methods for detecting and quantifying lipophilic and hydrophilic biotoxins, specifically in mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas). Using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), this method achieves high sensitivity and specificity for multi-class toxin analysis. To address matrix effects, matrix-specific calibration was applied, yielding linear calibration curves (R² ≥ 0.99) and recovery rates between 96.56% and 103.56%. The method also demonstrates excellent sensitivity, with detection limits (LD) ranging from 0.04–0.58 µmol·kg⁻¹ and quantification limits (LQ) from 0.15–1.82 µmol·kg⁻¹, and high precision with relative standard deviations (RSD) ≤ 2.8%. These validated methods were ISO/IEC 17025 accredited, underscoring their robustness and reliability for regulatory monitoring and food safety assurance.

The INSTM laboratory, B3Aqua, functions as Tunisia’s National Reference Laboratory for biotoxin monitoring within the national network, under the Ministry of Agriculture. By conducting regular sampling and analysis of shellfish from aquaculture sites in the Bizerte region, B3Aqua ensures these products meet stringent safety standards before consumer distribution. In collaboration with local producers, B3Aqua also implements preventive measures and provides technical guidance on aquaculture best practices. Through these efforts, B3Aqua plays a vital role in safeguarding public health, supporting sustainable aquaculture, and enhancing the quality of Tunisian aquaculture products for both domestic and international markets.

Keys words: PSP, ASP, DSP, LC/MS/MS analysis, ISO/CEI 17025. Monitoring, Farmed Shellfish,