One Health aquaculture - everyone's business

Aquaculture has evolved into a major global food sector. Rapid growth necessitates an evidence and policy makeover fit for a doubling of output by 2050. A One Health approach, drawing on a broad expertise outside of traditional aquatic disciplines is now needed to realise it's full potential

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One third of all animal protein produced on the planet comes from the water. Half of this is from aquaculture - mainly the farming of fish, crustaceans and molluscs - in our global rivers, lakes and oceans.

The sector is diverse, ranging from production of predatory fish species in marine waters through the culture of molluscs and shrimp in coastal habitats to the farming of carp, tilapia and catfish in inland rivers and lakes. Seaweed contributes a significant additional contribution, mainly in tropical waters. With a projected flat-lining of output from the global capture fishery in the next three decades, aquaculture will become the dominant provider of protein from aquatic habitats to a population projected to reach 10 billion by 2050.

Tilapia - a freshwater fish with significant potential to feed the world (Photo credit: Professor Charles Tyler, Centre for Sustainable Aquaculture Futures, University of Exeter)

In our paper, published today in Nature Food (https://www.nature.com/articles/s43016-020-0127-5)  we consider this projected growth through the lens of One Health - the philosophy which simply reminds us that the health of all life on earth is inter-connected. Importantly, a One Health approach takes in to account the effect of maintaining or altering the 'health status' of one part of the environment-human-organism triad on other parts of that system; a concept amply highlighted during the current Covid19 pandemic in which intricate relations between human health and that of our wildlife and the environment in which it resides, has been laid bare.  

As an aquatic animal pathologist I observe the term 'One Health' being regularly used in veterinary and medical fields, particularly when applied to examples of disease transmission between animals and humans (so-called 'zoonoses' such as SARS-Cov2) or, where control of disease in domesticated terrestrial livestock may lead to indirect benefits to farmer communities due to (say) the improved yield or profit which may flow from this.

However, while demonstrating that health of animals and humans is of course inter-connected, these nuanced examples seem somehow to fall short in delivering on the original philosophy of One Health - in particular, they rarely take account of the role of the broader environment in animal and human health outcomes (and vice versa). Whilst far from a criticism of veterinary and medical disciplines, the effect of assigning One Health principles only to such specific examples may serve to exclude a much broader array of research, policy and societal perspective that will inevitably be needed to solve some of the most pressing environment, animal and human health issues of our time. To illustrate this point, when audiences are asked the question 'do you consider yourself working in One Health?' during presentations I have given on this topic, most people do not raise their hand. This suggests that 'One Health' itself may be seen as a rather exclusive topic to be specialised in rather than the all-inclusive mode of operation with the potential to bring together multiple disciplines and perspectives to solve complex problems. 

With this in mind, we set out to flip the One Health paradigm back to it's original intent - to apply it to whole systems - in which optimising 'health' in it's broadest sense will have an overall positive outcome on the organisms, humans and environments associated with that particular system. Food systems seem an obvious target for this - being reliant on a healthy environment (and the ecosystem services which it provides) for creation of food products which ideally benefit both the producer and the consumer; and conversely, do not create conditions of harm for the environment, producers, consumers or, farmed stock.

Which One Health 'success metrics' should be 'designed-in' to food systems in order to have confidence that the system itself is making best attempts to optimise environment-organism-human health?

We applied this to aquaculture - a diverse sector in which environmental sustainability issues levelled against it in recent years may be masking a series of much broader societal and environmental benefits that may associate with increased farming in water:

Aquaculture One Health - designing-in 'success metrics' (outside of wheel) across environment, organism and human health will require research, evidence, policy and legislation input (inside of wheel) from a wider array of disciplines than   currently deployed. Achievement of success metrics in one part of the wheel   (e.g, environment) will positively impact outcomes in other parts of the wheel 

We brought together a much broader array of experts than may traditionally have been invited to engage in such discussions; many of whom would not have considered themselves as aquaculture specialists. Asking questions about the quality of employment that should be offered by the sector, the role of gender in successful operation of the system, the effect of water quality on provision of healthy and safe food products, the role of biosecurity in controlling disease and anti-microbial resistance hazards, the potential for delivering nutrition to the poorest communities, and so on. These elements of course all require specialist input - providing the evidence that can be then be used to inform policy and legislation - across a broad array of environment-organism-human health metrics which comprise this One Health approach. During summing-up at a series of workshops where this kind of approach was taken, individuals were asked again whether they would feel willing and able to contribute to One Health design of sustainable aquaculture (or other food) systems - most were now confident enough to raise their hand. 

Without wishing to underplay the complexities of food system design, it is certainly timely to take another look at how we all interact with these systems. Food is perhaps the most common of all denominators in our daily lives - and, the systems which create it have some of the greatest potential to harm or heal ourselves and the planet on which we live. Better food system design - perhaps using the type of inclusive One Health framework proposed in our paper - is something we must all engage with.

If asked whether you work in One Health? The answer is yes, you do.      

Grant Stentiford

Animal and Human Health Theme Lead, Cefas

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