Modelling paralytic shellfish toxins (PST) accumulation in Crassostrea gigas by using Dynamic Energy Budgets (DEB)

• Published in: Journal of Sea Research
• Main Authors: Pousse, Emilien, Flye-Sainte-Marie, Jonathan, Alunno-Bruscia, Marianne, Hegaret, Helene, Rannou, Eric, Pecquerie, Laure, Marques, Gonçalo, M., Thomas, Yoann, Castrec, Justine, Fabioux, Caroline, Long, Marc, Lassudrie, Malwenn, Hermabessiere, Ludovic, Amzil, Zouher, Soudant, Philippe, Jean, Fred
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Mathématiques de Bretagne Atlantique (LMBA), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Instituto Superior Técnico, Technical University of Lisbon, School of Chemistry Wollongong, University of Wollongong Australia, ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), ANR-13-CESA-0019,ACCUTOX,De la caractérisation des déterminants de l'accumulation des toxines paralysantes (PST) chez l'huître (Crassostrea gigas) au risque sanitaire pour l'homme dans son contexte sociétal(2013), ANR-11-LABX-0020,LEBESGUE,Centre de Mathématiques Henri Lebesgue : fondements, interactions, applications et Formation(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Pacific oyster; Modelling; Dynamic Energy Budget (DEB); ACL; Alexandrium minutum; Paralytic shellfish toxins (PST); [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Pacific; Crassostrea gigas
• Online Access: https://hal.univ-brest.fr/hal-02114653; https://hal.univ-brest.fr/hal-02114653/document; https://hal.univ-brest.fr/hal-02114653/file/Pousse_etal_JoSR_2019.pdf; https://doi.org/10.1016/j.seares.2018.09.002

International audience As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dino-flagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the physiological status of oysters. The accumulation was modelled through the dynamics of two toxin compartments: (1) a compartment of ingested but non-assimilated toxins, with labile toxins within the digestive gland eliminated via faeces production; (2) a compartment of assimilated toxins with a rapid detoxification rate (within a few days). Firstly, the DEB-PST model was calibrated using data from two laboratory experiments where oysters have been exposed to A. minutum. Secondly, it was validated using data from another laboratory experiment and from three field surveys carried out in the Bay of Brest (France) from 2012 to 2014. To account for the variability in PST content of A. minutum cells, the saxitoxin (STX) amount per energy units in a toxic algae (ppsT) was adjusted for each dataset. Additionally, the effects of PST on the oyster bioenergetics were calibrated during the first laboratory experiment. However, these effects were shown to depend on the strain of A. minutum. Results of this study could be of great importance for monitoring agencies and decision makers to identify risky conditions (e.g. production areas, seawater temperature), to properly assess detoxification step (e.g. duration, modalities) before any commercialization ...