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Diseases associated with ornamental and non-native aquatic species - FC11100

Description
One of the most significant risks for the introduction and development of diseases of aquatic animals derives from the import of non-native aquatic species intended for aquaculture or ornamental use. This proposal aims to study some of these species and associated diseases currently considered most relevant (with regard to risk and impact) to the aquatic environment in England and Wales. The proposed work can be divided into six themes; four specific research themes, a fifth theme relating climate change to ornamental and non-native imports and associated aquatic animal health, and a sixth flexible element designed to enable Cefas to address data gaps identified in the Import Risk Assessment (IRA) for ornamental fish produced within Defra project F1185.
The four specific research themes proposed are:
1. Understanding the epidemiology of epizootic ulcerative syndrome (EUS) in UK species. To advise and define disease control policy for the UK, we aim to study survival and transmission parameters of the pathogen in UK native species.
2. Better understanding of the disease risk posed by imported Asian cyprinids carrying spring viraemia of carp virus (SVCV). We propose to assess the virulence of selected Asian SVCV for carp to better understand why Chinese producers do not appear to experience outbreaks of disease and yet, contrary to health certification, the imported animals have proved to be carriers of SVCV.
3. The impact of ranaviruses in ornamental species. We aim to investigate and develop an understanding of the observed differences in the pathogenicity of different ranaviruses amongst fish and amphibians in particular to establish the route of entry and spread of ranavirus within the host.
4. Assessment of the disease risk from imported “Doctor fish”. There has been a rapid expansion in the number of businesses offering ichthyotherapy treatments in the UK and the associated import of “Doctor fish” (Garra rufa and Cyprinion macrostomus) for these purposes. Recent disease screening undertaken at Cefas on imported Garra rufa has identified a serogroup C aquabirnavirus and a number of bacterial species in significant numbers, some of which are potential pathogens of humans and some are known to cause mortality in fish. We aim to assess and characterise these isolates and address the risk these fish and pathogens pose to UK species.

The fifth theme addresses the potential impact climate change may have on the aquatic animal health issues associated with ornamental and non-native species and relates this to national biosecurity. The proposed work will identify and collate relevant information resources, identify pathogens and ornamental species most likely to establish in E&W currently and under given climate change scenarios.

The sixth flexible theme is designed to allow targeted work to be undertaken on specific high risk areas indicated in the ornamental species IRA presented under F1185. This should include development work towards appropriate diagnostic tools for potential pathogens associated with the trade of ornamental species.
Objective
Specific Research Theme 1 - Understanding the epidemiology of epizootic ulcerative syndrome (EUS) in UK species.
1.1 To develop tools for the detection and quantification of A. invadans.
1.2 To establish in vitro survival parameters for A. invadans.
1.3 To establish transmission parameters for EUS.
1.4 To assess the likelihood of establishment of disease by experimental challenge in relevant UK species.

Specific Research Theme 2 - Better understanding the disease risk posed by imported Asian cyprinids carrying spring viraemia of carp virus (SVCV).
2.1 To undertake molecular characterization of Asian SVCV isolates from UK, China and North America to examine possible determinants of pathogenicity.
2.2 To investigate the pathogenicity of selected Asian SVCV isolates by experimental challenge of carp.

Specific Research Theme 3 - The impact of ranaviruses in ornamental and non-native species.
3.1 To investigate the susceptibility of UK fish and amphibians to relevant ranaviruses showing differing pathogenicity in different hosts.
3.2 To investigate the pathogenicity of early UK ranavirus isolates to goldfish and carp

Specific Research Theme 4 – Assessment of the disease risk from imported “Doctor fish”.
4.1 To characterise the serogroup C aquabirnavirus isolated from Garra rufa and assess its pathogenicity to UK native species.
4.2 To undertake an assessment of the range of species imported under the title “Doctor fish” for fish spa businesses and to determine from import location and sampling their relevant pathogen risk .

Theme 5 – Climate change scenarios affecting Aquatic Animal Health
5.1 To identify and collate the resources available relevant to climate change and Aquatic Animal Health in E&W.
5.2 To develop a list of “risk species” (imported, likely to survive, carrying pathogens).
5.3 Review data on survivability and permissive temperature ranges for pathogen hazards identified by the IRA (to be completed under F1185).
5.4 To characterise current disease threats associated with ornamental fish and future threats based on various climate change scenarios.

Flexible Research Theme 6 – Response to Impact Risk Assessment for ornamental species
6.1 To address priority data gaps identified in the IRA for ornamental fish as agreed with Defra project officer.
6.2 To identify and develop relevant diagnostic tools for identified potential pathogens associated with the trade of ornamental species.
Time-Scale and Cost
From: 2012

To: 2015

Cost: £405,000
Contractor / Funded Organisations
C E F A S (CEFAS)
Keywords
Fish              
Fish Disease              
Fields of Study
Fish Health and Aquaculture