Aquatic pathogens and biofouling: pilot study of ostreid herpesvirus 1 translocation by bivalves

Abstract

Ostreid herpesvirus 1 (OsHV-1) has caused mass mortalities in Pacific oysters (Crassostrea gigas) in Europe, Australia, and New Zealand. While aquaculture-associated movements of infected Pacific oysters are a well-known cause of OsHV-1 spread once established in a region, translocation via biofouling of aquaculture equipment or vessels needs further investigation to explain the more distant spread of OsHV-1. Laboratory experiments were designed to test for transmission of OsHV-1 between infected and naïve Pacific oysters via a simulated biofouling translocation scenario. Three common biofouling species [Sydney rock oysters (Saccostrea glomerata), Mediterranean mussels (Mytilus galloprovincialis) and Pacific oysters] were tested as intermediaries using a cohabitation challenge with Pacific oysters infected by injection. Transmission occurred, albeit for one of eight replicates when Pacific oysters were the intermediary species. This demonstrated a possible pathway for pathogen spread via biofouling containing Pacific oysters while highlighting the complexity of OsHV-1 transmission. Such complexities require further investigation to inform future risk assessments and management of fouled aquaculture equipment and vessels.

KEYWORDS:

• bivalves
• disease
• transmission
• Saccostrea glomerata
• Mytilus galloprovincialis
• Crassostrea gigas

Acknowledgements

This project was commissioned by the Ministry of Primary Industries, New Zealand and funded by the MPI’s Operational Research Programme (Project 405365). The authors would like to thank Slavicka Patten, Alison Tweedie, Stuart Glover and Craig Kristo for technical support, Bruce Alford, Dale Witchard, for providing the Pacific oysters and the Sydney rock oysters. The authors acknowledge the technical input of Richard Whittington, Joy Becker, Anjali Pande, Kevin Ellard, James Forwood, and Mark Bestbier for experimental design, project oversight, and manuscript review. Abraham Growcott, Giulia Raponi, Daniel Kluza, and Enrico Perotti also reviewed the manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.