Aquaculture: Farming the Water


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Aquaculture faces challenges similar to traditional livestock production.

Most distributor sales representatives (DSRs) serving large-animal clinics and customers are familiar with cattle, hogs, and poultry. Yet, aquaculture is a growing field and faces many of the same pressures as the livestock industry.

Seafood consumption is generally increasing in many parts of the world, and farmed aquaculture is helping create a stable source of supply to meet that demand. In fact, aquaculture already supplies 50% of the fish consumed across the world today. Already, fish and shellfish make up 6% of global protein consumption, according to the Food & Agriculture Organization (FAO) of the United Nations.

Sustainability: A moving target

Aquaculture is not one thing and can vary depending on the region and species of fish or shellfish. Every country with a sizable aquaculture industry is similarly concerned about sustainability, said Morten Nordstad, President PHARMAQ, a business of Zoetis.

“Any farming could have an environmental footprint. Water is a limited resource, especially with freshwater fish,” he said. “Every country has to be focused on how to be sustainable and how to use the environment while treating the animals well.”

Sustainability goals and targets can vary across continents, with varying regulatory bodies and laws. One part of sustainability is effective disease management, including diagnostics, surveillance, prevention, and treatment.

Handling matters

An important pillar for the aquaculture industry – which will sound familiar to American livestock producers – is ensuring a healthy immune system prior to encountering disease challenges. This includes lowering the stress from changes in water temperature, handling, and crowded production facilities.

Several companies are exploring immune-boosting products that can help support general fish health or may have benefits against specific diseases. Good genetic material also supports healthy fish with robust growth.

“We have good genetic material,” Nordstad said. “Eggs come from healthy mothers and fathers and have a good starting point. Then, we work hard to avoid stress from handling, with extra care in cold water when the fish are more susceptible.”


Understanding disease threats is critical for addressing new and emerging issues. Surveillance is largely the responsibility of the individual producer. However, some diseases are reportable to local authorities.

“With fish, we really have to understand the disease picture. Like any livestock, when you put them together, they can transmit disease,” he said. “In the wild, they can have more distance – we all know about social distancing now.”

Polymerase chain reaction (PCR) is the most commonly used detection method for identifying disease in fish and shellfish, which is the same type of test cattle producers may use for mastitis or Johne’s Disease. PHARMAQ conducts and reviews hundreds and thousands of PCR samples to help customers identify and create a management plan for pathogens in their farms.

“We have to understand if a disease is increasing in prevalence,” Nordstad said. “We may have to recommend leaving a herd quiet to make sure they can recover. We thought five years ago we maybe wouldn’t see some disease problems anymore. Some diseases do go away, but others tend to be ever-present and difficult.”

Vaccination and treatment

Fish will still encounter disease, even with proper handling, frequent testing, and ready immune systems. That’s when vaccination and treatment protocols come in.

“Fish are special because you have to vaccinate them when they are young and small,” he said. “For example, salmon start in freshwater and go out to sea. We have to be sure to get the right combinations of antigens at a very early stage.”

Each species has its own disease challenges, and vaccination is critical to preventing losses from disease, Nordstad said.

“We cannot use the same vaccine in Norway as in Chile,” he said. “We must build a platform for applying technology and understand the difference between farms in the Mediterranean or the open ocean.”

Today, manufacturers are creating up to seven antigens in a single vaccine, which are delivered in a micro-dose suitable for the size of the fish. Vaccination is a way aquaculture producers can improve the health and welfare of their fish, which is a concern among customers across the world.

“Customers who buy fish are concerned about farming practices,” Nordstad said. “That means something – even to a fish.”

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