Aquafarming, more commonly called aquaculture, is the practice of raising aquatic organisms under controlled conditions rather than catching them from the wild. It covers far more than fish: shrimp, oysters, clams, seaweed, and dozens of other species are all commercially farmed in water. In 2022, global aquaculture production hit 130.9 million tonnes, surpassing wild-capture fisheries for the first time in history. That milestone marked a fundamental shift in how the world sources seafood and aquatic products.
What Counts as Aquafarming
The Food and Agriculture Organization of the United Nations defines aquaculture as “the farming of aquatic organisms, including fish, molluscs, crustaceans, and aquatic plants.” Two things separate it from simply harvesting wild populations. First, there’s deliberate intervention: stocking, feeding, protecting from predators, or managing water conditions. Second, someone owns the stock being cultivated, whether that’s an individual, a company, or a cooperative.
In practical terms, aquafarming ranges from massive offshore salmon pens in Norway to small tilapia ponds in rural Egypt to rope-grown mussel operations off the coast of New Zealand. If a person is actively raising an aquatic organism rather than just pulling it from the water, it qualifies.
What Gets Farmed
The diversity of farmed species is wider than most people realize. Among fish, carps and related species dominate globally, accounting for over 31 million tonnes in 2021. Tilapia (about 6.3 million tonnes), catfish (6.1 million tonnes), and salmon and trout (4.2 million tonnes) round out the top groups. These species vary enormously in how they’re raised and what they eat.
Shellfish farming is its own massive sector. Shrimp and prawns lead at roughly 7.3 million tonnes, followed by oysters (6.7 million tonnes), clams and cockles (5.8 million tonnes), crayfish (2.7 million tonnes), and scallops (2.1 million tonnes). Many shellfish species are filter feeders, meaning they pull nutrients directly from the water and don’t need manufactured feed at all.
Then there’s seaweed. Brown and red seaweeds together totaled about 35 million tonnes in 2021, making them some of the most heavily farmed aquatic organisms by sheer volume. Seaweed goes into food products, animal feed, fertilizers, cosmetics, bioplastics, and pharmaceutical ingredients.
How Aquafarms Work
The farming method depends on the species, the environment, and the scale of the operation. The most common setups include open-water net pens (cages anchored in the ocean, a lake, or a river), coastal ponds (excavated or natural enclosures near shorelines), and freshwater ponds or tanks on land. Each system presents different trade-offs in cost, disease management, and environmental footprint.
A newer approach gaining traction is recirculating aquaculture systems, or RAS. These are land-based facilities that filter, adjust, and reuse their water rather than continuously drawing from a natural source. Because the water cycles through treatment, operators can precisely control temperature, oxygen levels, and waste removal. RAS facilities can be built almost anywhere, regardless of local water conditions, which means fish can be raised closer to the markets where they’ll be sold. That cuts transportation distances and the carbon emissions that come with them.
RAS also eliminates some of the biggest headaches of open-water farming. Fish can’t escape into wild ecosystems, and the closed loop limits the spread of diseases and parasites between farmed and wild populations. The main drawback is cost: building and running a recirculating facility requires significant upfront investment and ongoing energy inputs to keep the filtration and water-treatment systems running.
Scale of the Industry
Aquaculture has grown from a niche food source to the world’s primary producer of aquatic animals. In 2022, farmed aquatic animals totaled 94.4 million tonnes, representing 51 percent of all aquatic animal production globally. Wild-capture fisheries, by comparison, produced 92.3 million tonnes and have remained essentially flat since the late 1980s. Total aquaculture production, including seaweed, reached 130.9 million tonnes.
The industry was valued at roughly $204 billion in 2020, with projections putting it at $262 billion by 2026. That growth rate of about 3.6 percent annually reflects rising demand for protein, stagnant wild fish stocks, and expanding operations across Asia, South America, and parts of Africa.
Environmental Risks
Aquafarming solves some problems while creating others. Open-water operations, particularly net-pen salmon farms, concentrate large numbers of fish in a small area. Uneaten feed and fish waste sink to the seafloor beneath the pens, increasing nutrient loads that can degrade local water quality and smother bottom-dwelling organisms.
Escapes are another persistent concern. When farmed fish break free from net pens, they can compete with wild populations for food and habitat. If escaped fish interbreed with wild relatives, the genetic consequences can reduce the overall fitness of wild stocks, potentially limiting their ability to adapt to changing environmental conditions. Disease transfer from farmed to wild fish is also a documented risk, particularly with parasites like sea lice in salmon farming regions.
Carnivorous species like salmon raise a separate resource question. Historically, it took more wild-caught fish (ground into fishmeal and fish oil for feed) than the salmon produced. That ratio has improved dramatically as the industry has substituted plant-based and alternative ingredients into feed formulations. Current estimates suggest salmon and trout farming is roughly net neutral, producing about as much fish biomass as it consumes. Most other farmed species are net producers of fish protein, meaning they generate more edible food than the wild fish used in their feed.
Environmental Benefits
Not all aquaculture carries the same environmental baggage. Shellfish like oysters, mussels, and clams filter water as they feed, actively removing excess nutrients and improving water clarity. Seaweed farming absorbs dissolved nutrients from coastal waters, which can help counteract pollution from agricultural runoff.
Seaweed farms also show promise for carbon capture. Research published in Nature found that organic matter falling from seaweed farms to the sediment below triggers chemical processes that increase the water’s alkalinity, its natural capacity to absorb and neutralize carbon dioxide. Unlike organic carbon that can break down and release CO₂ back into the atmosphere within decades, carbon stored through this alkalinity pathway stays locked in the ocean system for thousands of years. Seaweed farming won’t single-handedly solve climate change, but it represents a food production method that can actively pull carbon from the atmosphere rather than adding to it.
Certification and Standards
As the industry has grown, so have efforts to distinguish responsible farms from poorly managed ones. The Aquaculture Stewardship Council (ASC) runs the most widely recognized certification program. Farms seeking ASC certification are audited against standards covering environmental sustainability and social responsibility. On the environmental side, auditors evaluate pollution controls, interactions with surrounding ecosystems, water and resource management, and biodiversity impacts. On the social side, they assess labor practices, worker safety, compliance with local laws, and relationships with surrounding communities.
Violations involving child labor, forced labor, human trafficking, or conditions that put workers’ lives at risk result in automatic critical findings. For consumers, an ASC label on farmed seafood signals that the product meets a defined set of environmental and labor standards, though no certification system is perfect, and the rigor of enforcement varies by region.
Why It Matters
Wild fisheries hit their ceiling decades ago. The ocean can only produce so much, and many stocks are already fished at or beyond sustainable limits. With global population still rising and demand for protein growing, aquafarming is filling the gap. The question is no longer whether the world will rely on farmed seafood but how well the industry manages the environmental and social costs that come with producing it at scale.