Host range and disease dynamics of viral pathogens of common carp (Cyprinus carpio), and their potential as biological control agents

Abstract

Common carp (Cyprinus carpio), hereafter referred to as carp, is a ubiquitous and destructive invasive fish in Minnesota and much of the world. There is a need for the development of species-specific, highly effective, and cost-efficient approaches for carp management that can be used across large scales. Pathogen biocontrol agents have previously been used in combination with conventional methods to control vertebrate pests at the landscape scale. Cyprinid herpesvirus 3 (CyHV-3; aka. Koi herpesvirus, KHV) and carp edema virus (CEV) are pathogens worthy of further investigation for carp biocontrol due to their host-specific pathogenicity. Both CyHV-3 and CEV are known to cause mass mortality events of carp and it is possible that carp populations can continue to decline after initial outbreaks. Despite the potential value of viruses as biocontrol agents, there are significant data gaps in the understanding of the distribution and disease ecology of carp-specific viruses in North America, a need for increased research capacity, as well as concern related to the risks of using microbial biological control agents in general. This dissertation is composed of research working to identify a safe and effective pathogenic biocontrol agent for carp. This work contributes to the understanding of the potential value of viral biocontrol of carp by identifying the distribution of CyHV-3 and CEV in Minnesota, obtaining a regional viral strain of CyHV-3 from a carp mortality event, assessing the host range and disease dynamics of these viruses, and by describing the natural ecology of CyHV-3 in laboratory disease trials and wild populations surveys.