Managing marine mollusc diseases in the context of regional and international commerce: policy issues and emerging concerns

Abstract

Marine mollusc production contributes to food and economic security worldwide and provides valuable ecological services, yet diseases threaten these industries and wild populations. Although the infrastructure for mollusc aquaculture health management is well characterized, its foundations are not without flaws. Use of notifiable pathogen lists can leave blind spots with regard to detection of unlisted and emerging pathogens. Increased reliance on molecular tools has come without similar attention to diagnostic validation, raising questions about assay performance, and has been accompanied by a reduced emphasis on microscopic diagnostic expertise that could weaken pathogen detection capabilities. Persistent questions concerning pathogen biology and ecology promote regulatory paralysis that impedes trade and which could weaken biosecurity by driving commerce to surreptitious channels. Solutions that might be pursued to improve shellfish aquaculture health management include the establishment of more broad-based surveillance programmes, wider training and use of general methods like histopathology to ensure alertness to emerging diseases, an increased focus on assay assessment and validation as fundamental to assay development, investment in basic research, and application of risk analyses to improve regulation. A continual sharpening of diagnostic tools and approaches and deepening of scientific knowledge is necessary to manage diseases and promote sustainable molluscan shellfish industries.

Infectious diseases in oyster aquaculture require a new integrated approach

“…Acceptability can be estimated with participation rates obtained from survey questionnaires to stakeholders. Considering that the effectiveness of disease control strategies relies on a collaboration between neighbouring farms [89,98], acceptability of disease control should be measured in the largest possible proportion of growers that participate in long-term activities. The perception of oyster farmers of recent disease mortality outbreaks of oysters and their consequences on their production areas, business and professional organization is the subject of ongoing study in France [107].…”

Fishing diseased abalone to promote yield and conservation

“…We considered perfect and cost-free infection diagnosis in our model, but most diagnoses have inherent uncertainty and take effort [49,51]. Our simple deterministic model is extendable to stochastic frameworks, and including uncertainty in the infection status would allow one to determine how much information about infection status one needs to target infected hosts.…”

Comparative immunogenomics of molluscs

“…1) is motivated importantly by notions that many molluscs are economically valuable food sources, especially in aquaculture (Carnegie et al, 2016), or may transmit infectious diseases of medical and veterinary relevance (Adema et al, 2012). Moreover, the highly diverse phylum Mollusca is second in size among animals only to Arthropoda and represents the generally understudied lophotrochozoan protostomes, one of three lineages of metazoan animals, along with ecdysozoan protostomes and deuterostomes (e.g.…”