Vibrio aestuarianus associated to Pacific oyster Crassostrea gigas mortality in the Ebro Delta, in the Catalan Mediterranean Coast

• Main Authors: Carrasco, Noèlia, Vezzulli, Luigi, Bertomeu, Edgar, Álvarez-Muñoz, Diana, Aranguren, Raquel, Fernández-Tejedor, Margarita, Roque, Ana, Andree, Karl B., Solé, Montserrat, Furones, M. Dolores
• Other Authors: European Commission, Ministerio de Economía y Competitividad (España)
• Format: Still Image
• Language: unknown
• Published: World Aquaculture Society 2018
• Subjects: Pacific; Webb; Crassostrea gigas; Pacific oyster
• Online Access: http://hdl.handle.net/10261/193473; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100003329

AQUA 2018, #WeRAquaculture we are the producers and investors, the scientists and technical advisors, the legislators and educators, the students, civil society organizations and consumers of farmed aquatic products, 25-29 August 2018, Montpellier, France The presence of Vibrio aestuarianus has been associated to mortality events in pre-commercial and commercial Crassostrea gigas Pacific Oyster in recent years in France and Ireland. However, no mortality events associated to this pathogen has been detected in the Mediterranean. In May 2017, when temperatures were around 20 ºC, C. gigas cultures in the Ebro bays (Alfacs and Fangar) experimented for the first time a massive mortality event of commercial size oyster. Different analyses for detecting the presence of pathogens (qPCR Saulnier et al. 2009 V. aestuarianus/ V. splendidus; qPCR Webb et al. 2007 herpesvirus OsHv-1), as well as presence of contaminants, were performed. Retrospective samples from 2016 were also studied. Results regarding presence of pathogens pointed out the detection of 22+/30 V. aestuarianus positive individuals for oysters with 50% mortality collected in April 2016 (EFCgAbr16), as well as 9+/30 positive individuals in May 2017 adult oyster mass mortality (FmCgMa17). Furthermore, in this last sample the presence of V. splendidus clade was also observed, however similar results were also observed in oyster with no mortality. The V. aestuarinus presence was corroborated by the Spanish National Reference Laboratory (CSIC-Vigo) on samples with mortalities collected from the same bay one month later. Results on contaminant analysis revealed the presence of metolachlor (organitrogen pesticide), bentazone (insecticide), methylparaben (endocrine disruptors), with levels ranging from less than 1 ng/g dry weight (dw) to 10 ng/g dw for both oysters experiencing mortality and with no mortality. Furthermore, esterase activities indicative of OP pesticide exposure did not suggest neurotoxicity signs caused by these compounds. Those results do not ...