Aquatic animal health is a major constraint on sustainable aquatic food farming systems, with global annual disease-related losses estimated at more than USD 6 billion. In low- and middle-income countries (LMICs), where aquatic animal diseases often spread quickly between small-scale aquaculture farms, vulnerable communities and their incomes can be especially hard hit.
A concerted focus on research and capacity sharing on controlling and preventing these diseases will, therefore, be critical to unleashing the sustainable development potential of aquatic food systems in LMICs. This is particularly true for diseases faced by affordable, low-commercial value species – such as carp, tilapia and catfish – that form a mainstay for many aquaculturists in Africa and Asia. And with aquaculture production projected to reach over 200 million tons by 2030, the importance of aquatic animal health research programs will only intensify.
At WorldFish, a CGIAR center, the importance of this critical area in advancing its mission of sustainably transforming aquatic food systems was recognized a decade back. Below is a look back at its journey as it bid farewell to Dr. Mohan Chadag, the lead for Aquatic Animal Health research area and welcomed its new lead, Dr. David Verner-Jeffreys.
From Barely There to an Award-Winning Program
Despite the importance and urgency of aquatic animal health, until 2014 WorldFish lacked a comprehensive program dedicated to it. This changed with the arrival of Dr. Chadag as one of WorldFish’s principal scientists. Carving out space in CGIAR’s then Livestock and Fish research program, coordinated by the International Livestock Research Institute (ILRI), Dr. Chadag created the beginnings of WorldFish’s aquatic animal health program.
“The main purpose of the program was to help farmers in Bangladesh and Egypt, but also to generate scientific evidence that can be used by policymakers,” explained Dr. Chadag. “Ultimately, our goal was to support and enable national governments and partners to implement sound national aquatic animal health strategies and biosecurity governance mechanisms.”
After its establishment as part of the CGIAR Livestock and Fish program, WorldFish’s aquatic animal health work found a home in the Fish Agri-Food Systems CGIAR research program from 2017 to 2021, and under an ILRI-coordinated One Health initiative from 2022 to 2024. Over the past decade, the program has been at the cutting edge of aquatic animal health research and practice, producing reports, forging international partnerships and publishing 63 scientific papers.
These outputs explored a wide range of topics, including epidemiology, diagnostics and surveillance for improving animal health, sampling for disease diagnosis, the role of microbiomes in aquatic animal health, and the interactions between genetics and disease. The program’s groundbreaking work on the rapid genomic detection of aquaculture pathogens was awarded first prize in the 2019 CGIAR Inspire Challenge.
In-line with WorldFish’s geographic focus on Asia and Africa, the program focused on improving the health and diagnostics of carp, tilapia and catfish to support underserved fish farmers in these regions. The Aquatic Animal Health team developed digital tools for farm surveys as well as fish epidemiology and disease diagnostic tools – such as the Lab-in-a-backpack, which enables rapid genomic detection of pathogens to control disease outbreaks in fish farms.
One Health and Aquaculture
In recent years, WorldFish’s aquatic animal health program has become increasingly involved in One Health – an approach that encompasses human, animal and environmental health. With a focus on reducing and managing human health risks from aquatic foods, One Health-related research at WorldFish centers on zoonotic pathogens, foodborne pathogens and food contaminants.
Mitigation of antimicrobial resistance (AMR) is another important component of WorldFish’s One Health work – a challenge listed by the World Health Organization as one of the top 10 global health threats for humanity.
“The contribution of aquaculture to AMR is less studied but an extremely important area for aquatic animal health research,” highlighted Dr. Chadag.
The aquatic animal health team at WorldFish are leading the way in this emerging field, producing a series of scientific papers that use systems thinking to study AMR in aquaculture food systems. For example, a seminal paper studied hotspots for the emergence of AMR in aquaculture systems in Vietnam, while another identified feasible interventions to reduce antibiotic use in farmed tilapia in Egypt, the world’s third largest tilapia producer.
Building In-Country Capacities
Aside from advancing global research, WorldFish scientists are building in-country capacities to implement national aquatic animal health strategies and farm-level biosecurity governance mechanisms, which will help prevent and control the spread of infectious diseases in animals.
The team has developed 15 introductory online courses for improving aquatic animal health. Ranging from fish sampling techniques to farm biosecurity, these resources are freely accessible to field enumerators, extension workers, fisheries officers, service providers, farmers and students in all partner countries.
In 2022-2023 alone, the team reached over 960 participants from national research institutions and governments in countries across Africa and Bangladesh with online and in-person trainings on aquatic animal health and One Health approaches.
Moving Forward with Continued Partnerships and Excellence
After 10 years at WorldFish – which caps an impressive 40-year career in aquaculture – Dr. Chadag has now retired, becoming WorldFish’s very first emeritus scientist. As he begins his new role, Dr. Chadag looked back at his time at WorldFish with pride. “After 10 years of work – including excellent partnerships with highly accredited research institutions around the world, a lot of donor-assisted projects and a prominent place in CGIAR research programs – we were able to establish a good program of aquatic animal health and One Health activities,” he concluded at a farewell presentation at WorldFish headquarters on 21 March 2024.
Leadership of WorldFish’s aquatic animal health research is now passed to Dr. David Verner-Jeffreys, who joined WorldFish in March 2024. Serving at the Centre for Environment Fisheries and Aquaculture Science (Cefas) as its head of the UK Antimicrobial Resistance Reference Centre, Dr. Verner-Jeffreys brings expertise developing One Health-based solutions to developing and implementing AMR surveillance in countries in Asia and Africa.
“I am delighted to be given the opportunity to build on the strong legacy bequeathed by Dr. Chadag,” says Dr. Verner-Jeffreys. “I look forward to working with the excellent team of scientists assembled by him to continue to develop One Health-based innovative solutions to the challenges posed by disease to the sustainable development of aquaculture. This will require working in close and truly interdisciplinary partnership with scientists both at WorldFish and CGIAR center, International Livestock Research Institute. As well as our stakeholders in industry, academia, civil society organizations and governments in the countries WorldFish operates in.”