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Influence of climate change on impact, surveillance strategies and contingency planning for notifiable aquatic animal pathogens - FC1207

The proposed study addresses the key Defra policy of improving the understanding of the likelihood of establishment, spread and impact of exotic pathogens of wild and farmed fish stocks under different climate scenarios. The work cuts across scientific divisions by studying the influence of different climate change predictions on host/pathogen ecology, river catchment biodiversity and consequences for aquaculture production. The multiple and interacting impacts of climate change on freshwater ecology of England and Wales will clearly influence the threat of notifiable fish diseases on both wild and farmed aquatic animals. The project will require the integration of knowledge surrounding climate change, land use, water chemistry, hydrology, freshwater salmonid fish behaviour, pathogen ecology and epidemiology.
The Atlantic salmon/Gyrodactylus salaris, host/parasite system is proposed as the focus of this study, as this system is ecologically and economically important, well studied, and the baseline models are already in place. Consequences to other important notifiable pathogens, such as Viral Haemorrhagic Septicaemia virus (VHSv) and Koi Herpesvirus (KHV) will also be investigated.
The impacts of climate change will not be geographically homogenous. The likely impact of climate change on the geographic distribution and density of wild salmonids in E&W will be assessed and mapped by building on work completed under defra project FC1177. In addition to the presence of the host, climate change, in particular seasonal water temperature profiles, will influence the dynamics of interaction between Atlantic salmon and G. salaris (and other host/pathogen systems). This relationship will be modeled and the result integrated into the risk maps. The movement of live fish is the main route of disease spread and largely driven by aquaculture. The likely impact of climate change on aquaculture and knock-on consequences for the spread of disease will therefore also be evaluated.
The main approach to be taken in this project is to develop existing computer based models to include a range of climate change predictions. The models will be parameterised using existing data from the scientific literature and available datasets, and, where required, experimental studies using a suitable host/pathogen model will be undertaken to address key data gaps.
The key outputs of this project will be a better understanding of the threat of notifiable fish diseases in response to climate change and to use this information to modify and develop contingency plans to control and prevent notifiable disease occurrence and enhance surveillance strategies.
Objective 1. Impact of climate change on host distribution and habitat suitability and consequences for pathogen establishment. Aims: 1) Review the way climate change scenarios may affect environmental conditions present in English and Welsh rivers and likely changes in surrounding land use. 2) Study the influence of such changes on the locations and densities of wild salmonid populations required for the establishment of Gyrodactylus salaris. 3) Assess consequences this may have on the parasite’s potential geographic range within England and Wales.

Objective 2. Climate change effects on pathogen spread via river flows, aquaculture practices and wild fish behaviours. Aims: 1) To investigate the effect of climate change on parasite spread via live fish movements between farms and fisheries by reviewing likely changes in the distribution of aquaculture and fisheries sites, and timing and quantity of live fish movements in response to climate change effects. 2) Model transmission of pathogens via the river network (by water flow or wild fish migrations) and live fish movements under different climate change scenarios.

Objective 3. The influence of climate change on host/pathogen dynamics of Atlantic salmon and G. salaris and other important notifiable pathogens. Aims: Investigate through modelling, and where required experimental studies, the effects of climate change scenarios on host/parasite population dynamics to assess the influence of changes in temperature and seasonality on 1) pathogen dynamics, 2) host susceptibility and 3) the timing of key host life-cycle events, e.g. smolting and reproduction.

Objective 4. Review current contingency and surveillance programmes for endemic and exotic pathogens in the context of likely changes in disease threat due to climate change. Aim: Develop recommendations for modification of contingency plans and surveillance programmes to improve resilence to the predicted changes from the threat of G. salaris and other important notifiable aquatic animal diseases that may arise under established climate change scenarios.
Time-Scale and Cost
From: 2012

To: 2014

Cost: £253,090
Contractor / Funded Organisations
Adapting to Climate Change              
Fish Disease              
Veterinary Surveillance