Suchergebnisse

Emerging pathogens threaten aquaculture industries worldwide. There is urgency to become better prepared and meet these challenges, as aquaculture is growing rapidly and will contribute increasingly to food security. There are important Pacific oyster production areas today as yet unchallenged by emergent OsHV-1 microvariants, notably in the Americas, and to these areas the viruses are an immediate threat. The ICES Workshop on Emerging Mollusc Pathogens addressed fundamental questions regarding capabilities (expertise, infrastructure) and communication (among the pathology community, regulation, and industry). We sought to identify areas warranting investment and support to manage emerging diseases in shellfish aquaculture industries, and to provide justification for resources to be directed to these areas for more effective management of shellfish health. Thirty-six priorities were identified spanning four areas: i) improving communication and frameworks ; ii) essential infrastructure and expertise ; iii) key research priorities ; and iv) the central role of husbandry in shellfish aquaculture health management. Improving communication in every regard was recognized as the greatest need. Better coordinating efforts, improving data sharing, and improving trust on the part of industry to create buy-in and improve reporting were among identified priorities. Regulatory frameworks were recognized as needing to be flexible, given the often urgent need to act with incomplete information when a disease emerges. For essential infrastructure and expertise the workshop emphasized the continued importance of traditional fields such as pathology, bacteriology and virology, which remain foundational to aquaculture health management. Maintaining laboratory capacity is critical, in distribution as well as technologically: there is value in maintaining not just national or pan-national laboratories but provincial governmental and academic labs too, which can be more intimately engaged with local producers, and familiar with local environments. Disease challenge models and facilities were additionally identified as essential for testing hypotheses, as was expertise in epidemiology, which is sharply limited for marine systems. Discussion of key research priorities highlighted the value of long-term studies for understanding infection patterns; for appreciating dynamics like resistance and tolerance evolution versus virulence evolution; and for understanding effects of changing environments. The importance of improving ecological and evolutionary perspective in general was emphasized, as was the need to develop strategies for monitoring the diversity of potential pathogens. Establishment of mol-luscan cell lines for viral work would be a particularly valuable tool. Aquatic animal husbandry offers myriad opportunities to control pathogens. Understanding inter-sections of disease with aquaculture production for different host-pathogen systems requires continued research investment. Focused investment is also required to pursue strategies emerging from this research, including disease resistance breeding. Tighter collaboration among practical aquaculture scientists and breeders and pathologists should be promoted. Finally, funding was recognised as a continuing challenge. Priorities of donors and funding agencies do not always match commercial and health management priorities; basic surveillance is a key area difficult to support. Short funding timelines challenge our ability to address key questions and challenges, including breeding to control diseases. And there is little funding for truly trans-national, collaborative research. Managing diseases to support aquaculture growth is a global problem that demands science that is equally global, which requires the capacity to build broad international collaborations. It would be immensely beneficial for sustainable aquaculture development if trans-national research initiatives in aquatic animal health and other aquaculture related fields could be established to support innovation in this area in the future.

Infectious agents such as the bacteria Vibrio aestuarianus or Ostreid herpesvirus 1 have been repeatedly associated with dramatic disease outbreaks of Crassostrea gigas beds in Europe. Beside roles played by these pathogens, microbial infections in C. gigas may derive from the contribution of a larger number of microorganisms than previously thought, according to an emerging view supporting the polymicrobial nature of bivalve diseases. In this study, the microbial communities associated with a large number of C. gigas samples collected during recurrent mortality episodes at different European sites were investigated by real‐time PCR and 16SrRNA gene‐based microbial profiling. A new target enrichment next‐generation sequencing protocol for selective capturing of 884 phylogenetic and virulence markers of the potential microbial pathogenic community in oyster tissue was developed allowing high taxonomic resolution analysis of the bivalve pathobiota. Comparative analysis of contrasting C. gigas samples conducted using these methods revealed that oyster experiencing mortality outbreaks displayed signs of microbiota disruption associated with the presence of previously undetected potential pathogenic microbial species mostly belonging to genus Vibrio and Arcobacter. The role of these species and their consortia should be targeted by future studies aiming to shed light on mechanisms underlying polymicrobial infections in C. gigas. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the EU project H2020 VIVALDI Grant No. 678589. We thank all the producers and people helping with sampling collection at the farming sites. We also thank the Ifremer ECOSCOPA network for producing and maintaining the oysters in the Bay of Brest. ; SI