Poverty alleviation through prevention and future control of the two major socioeconomically-important pathogens in Asian aquaculture.

Recent estimates predict that the global population will rise to ~ 9 bn by 2050. Of that growth, the majority is predicted to take place within Africa, the Middle East and throughout Asia. As the available land for agriculture becomes limited and as wild fish stocks become depleted, it is essential that aquaculture production is sustainably enhanced to ensure global food security and poverty alleviation for all human kind.
Infectious disease outbreaks are the key limiting factor to the sustainable expansion of the aquaculture industry. Many diseases exist in wild populations but only become problematic when crop species are held at high densities and under stressful conditions. These conditions are often associated with aquaculture. Attempts have been made to meet the challenge of disease by developing vaccines or prophylactic treatments to prevent disease or 'boost' the host immune system. Unfortunately, in the many cases in Asia these strategies have failed; vaccines have proved ineffective, too expensive, or are unrealistic to administer at farm scale. Immune stimulants and probiotics have often failed to provide consistent or sustained protection in shellfish. We argue that the approach to disease prevention must be radically rethought.
We do concede that regulating the culture environment alone will be insufficient to reduce the impact of all future diseases. We also advocate the continued development of novel understanding of the fundamentals of host-pathogen interactions. This knowledge will identify pathways of pathogen infection that could be exploited in the future leading to the development of more universal and cost-effective control methods.
We will quantify the socioeconomic impact of two key diseases of Asian aquaculture. This will inform the design of experiments to quantify the role of the pond environment (e.g.: temperature, salinity, diet, etc) in regulating the occurrence of infectious outbreaks. Outputs will be used to recommend novel Best Management Practice (BMP) for farmers in Low Income Countries (LICs). Through collaborative engagement, these new BMPs will be developed within the farming communities in Bangladesh and India to ensure their efficacy. The proposed approach represents a more economically realistic option for farmers working in LICs and will provide a first step towards poverty alleviation through minimising risk. We believe that this raised awareness of controlling environment quality to minimise disease has the potential to generate highly significant short term positive impacts.
Simultaneously, we will use state of the art molecular methods to develop rigorous new understanding of the host-pathogen interactions in these diseases and use that knowledge in future projects to identify novel universal and sustainable intervention methods and for genetic improvement programmes for high health crops.

Likely targets for our research are the current most socioeconomically devastating diseases in Bangladesh and India: White Spot Disease (WSD) of shrimp, which is caused by White Spot Syndrome Virus (WSSV), and infection with the fungus-like oomycete Aphanomyces invadans (previously Epizootic Ulcerative Syndrome (EUS)) causing large-scale mortalities of farmed fish, especially major carps. Minimising the risk of these disease outbreaks under farm conditions in Bangladesh and other LICs is thus a vital short term priority. We therefore propose that there is an essential and urgent requirement to optimise novel approaches to good BMP.
Our trilateral consortium will facilitate real cross fertilization of expertise and ideas and will build scientific and aquaculture capacity in the three countries presented. We genuinely believe that our collaboration will support the sustainable enhancement of the aquaculture industry and alleviate poverty by developing a holistic view of the importance of a healthy and resilient aquaculture crop and culture system.

Infectious disease outbreaks represent a key limitation to the necessary sustainable expansion of the aquaculture industry to meet the challenges of Global Food Security and poverty alleviation. For the majority of the socioeconomically devastating diseases in fish and shellfish aquaculture in Asia there is no clear mechanistic understanding of host/pathogen interactions that might mediate disease susceptibility, or systematic understanding of the role of the rearing environment in determining the outcome of infection.
We will systematically identify the evidence for potential environmental regulation of pathogen infection and disease progression. We will do this for two diseases, one of decapod crustaceans and one of fish in Asian aquaculture. Using controlled laboratory exposures in crustaceans and fish, we will expose them to different rearing environments and measure changes in immune gene transcription, immune phenotype and susceptibility to infection. These data will identify critical limits to host immune performance, but also pathogen virulence, which might be exploited by farmers as sustainable solutions for disease management in the short term.
We will also examine host-pathogen interactions for the same two diseases in vitro and in vivo. We will compare the transcriptional response in susceptible and resistant host species, to identify host and pathogen factors that determine susceptibility or resistance to infection. This study is novel in that it will capture both host and pathogen responses. We will be able also to identify the molecular mechanisms that underpin resistance (or partial resistance) both within and between different commodity crop species.
Using these new data as a platform, we intend to develop future research projects to mature new technologies or techniques for intervention and control of infectious diseases, both current and emerging, which are relevant and appropriate to the context of farmers in LICs and elsewhere.

This project is applied and impact-focussed. This project will be of direct benefit for poverty alleviation in the short and long term in shrimp and fish farming communities in Low Income Countries (LIC), including Bangladesh.

Firstly, we will provide a novel understanding of key environmental conditions that determine disease outcome from infectious pathogens. This knowledge will be of use, in the short term, to prevent, or minimise, disease outbreaks impacting social and economic wealth creation in LIC farming communities. Secondarily, we will create a step change in our understanding of pathogenicity and host defence responses in key fish and crustacean species that support export markets in LICs and in India. This will ultimately lead to much needed sustainable and context-relevant control strategies and technologies that are currently not available to the farming communities in LICs.

Knowledge exchange, farmer engagement and empowerment are key themes in our project that will create successful outcomes. Knowledge exchange will begin at the start of the project (Task 1). Farming communities will quantify their experience of the socioeconomic costs of disease in their industry, and also the costs of current management or mitigation strategies. In Task 2 farmers will, after training and with assistance, take responsibility for assisting with the epidemiological sampling programme. This will build capacity within those communities and will also provide an important route by which stakeholders (fishers, fishing communities, Fishery Officers and policy makers) will, in part, determine the experimental work programme (Task 3). In Task 4 a series of sensitization workshops will provide the vehicle by which the consortium will first present our findings and then invite stakeholder input to develop, revise or rationalise these recommendations from their own experience and through implementation. Once our recommendations have been revised and tested by the community, they will be rolled out to the wider communities in both countries through liaison with the Department of Fisheries in Bangladesh and through direct consortium contact with the World Organisation for Animal Health (OIE) and the Organisation for Economic Co-operation and Development (OECD).

This project will also build scientific capacity in all three countries. Through collaboration and training, researchers in Bangladesh and India will gain competence in methods for socioeconomic research and advanced molecular biology. Academics in India and UK will gain knowledge and experience of the challenges to aquaculture, and existing solutions, in both India and Bangladesh. Scientific collaboration and training will be fostered through in person visits between the UK and India and Bangladesh and India, through regular on line contact and through yearly consortium meetings that will rotate through the host countries.

The general public will benefit from this research in a number of ways because our work will ultimately safeguard food production, which is important for both the Asian and UK markets. Particularly in the UK, there is a comparative lack of understanding of the joint problems of global food security and poverty alleviation in LICs.

We will exploit existing avenues for public engagement in the UK through the UK partners, including public lectures and through student teaching. We have already set up a Facebook website dedicated to our research. This website (https://www.facebook.com/groups/934358809930397/) will go public from the moment the work begins and all our major findings will be reported here along with the websites of the individual PI's.