Aquaculture

Lore & Background

Aquaculture has ancient roots but modern expansion accelerated in the 20th century, driven by stagnation in wild fisheries and overexploitation of marine species. Domestication of aquatic species involves fewer risks to humans than land animals, as no human pathogens of comparable virulence to smallpox or diphtheria have emerged from marine species.

Reader's Guide

It helps reconstruct populations of endangered aquatic species and improves habitats. However, the industry faces challenges: products from several kilograms of wild fish are used to produce one kilogram of piscivorous fish like salmon, though plant and insect-based feeds are being developed. The FAO describes aquaculture as one of the industries most directly affected by climate change. Some forms have negative environmental impacts, such as nutrient pollution or disease transfer to wild populations. Biological control methods, such as using cleaner fish to manage parasites, are already employed. The industry's growth depends on finding alternative protein and oil sources for feed to avoid over-exploitation of forage fish. Future developments may rely on microorganisms, but greater funding and research are needed.

Did You Know?

• Domestication statistics for land and marine species are not reliably established; verified figures are unavailable from authoritative sources.
• In 2016, aquaculture was the source of 96.5% by volume of the total 30.1 million tonnes of wild-collected and cultivated aquatic plants combined.
• Freshwater systems dominate aquaculture production of aquatic animals, accounting for 64 million tonnes (63%) compared to 38 million tonnes (37%) from marine and coastal systems.

Global Scale and Geographic Concentration

Aquaculture has grown into a massive global industry. By 2019, reported output exceeded 120 million tonnes worth roughly 274 billion US dollars, and by 2022 that figure climbed to 130.9 million tonnes valued at 312.8 billion dollars. Yet the FAO itself cautions that the reliability of these reported numbers is questionable. Geographically, the industry is heavily skewed: in 2024, Asia produced around 89 percent of the world's farmed aquatic animals, with Latin America and the Caribbean at 3 percent, Europe and Africa each at 2 percent, and Northern America and Oceania trailing behind at 0.4 and 0.2 percent respectively. Five nations—China, Indonesia, India, Vietnam, and Bangladesh—accounted for 82 percent of total output. Freshwater systems dominate, contributing 64 million tonnes (63 percent) of aquatic animal production, while marine and coastal systems supplied the remaining 38 million tonnes (37 percent). Aquaculture production now surpasses that of capture fisheries, and the sector's relative GDP contribution spans a wide range from 0.01 to 10 percent depending on the country.

Domestication and the Blue Revolution

The push toward aquaculture was driven by stagnating wild fisheries and rising demand for quality protein. Early proponents envisioned a Blue Revolution mirroring the Green Revolution that had transformed terrestrial agriculture. In 1973, ocean explorer Jacques Cousteau urged humanity to turn to the sea with new understanding and technology to feed growing populations. The domestication effort has been remarkably recent: as of 2007, roughly 97 percent of the 430 cultured species had been domesticated in the 20th or 21st century, with an estimated 106 added in the decade before 2007. By comparison, only 0.08 percent of known land plant species and 0.0002 percent of known land animal species have been domesticated, versus 0.17 percent of marine plants and 0.13 percent of marine animals. A typical domestication project takes about a decade of research. Notably, marine species pose far fewer zoonotic risks than land animals—no human pathogens of comparable virulence to smallpox or diphtheria have emerged from cultured marine species.

Cultivation Environments and Methods

Aquaculture is practiced across a spectrum of settings. Onshore systems—tanks, ponds, raceways, and aquaponics—give operators full control over water quality, oxygen levels, feed, and temperature. Inshore operations sit in sheltered shallow waters near a coastline, exposing the stock to more naturalistic conditions. Offshore aquaculture, conducted in cages, racks, or bags within fenced sections of open water, subjects organisms to diverse natural forces including ocean currents, diel vertical migration, and nutrient cycles. The FAO defines the practice as requiring some form of intervention—regular stocking, feeding, predator protection—and implies ownership of the cultivated stock. Beyond single-species farming, integrated approaches like aquaponics and integrated multi-trophic aquaculture combine fish rearing with aquatic plant cultivation. The range of cultured organisms spans fish, crustaceans, mollusks, algae, and ornamental species, with mariculture specifically denoting seawater and lagoon-based operations.

Sustainability Pressures and Environmental Stewardship

The industry faces significant sustainability challenges. In current practice, producing one kilogram of a piscivorous species like salmon requires several kilograms of wild fish for feed, raising concerns about over-exploiting forage fish. Researchers are developing plant- and insect-based feeds to reduce this dependency. The FAO identifies aquaculture as one of the industries most directly affected by climate change and its impacts. Some farming operations contribute nutrient pollution or transfer diseases to wild populations. To mitigate these effects, biological control methods are already in use—cleaner fish such as lumpsuckers and wrasse help manage sea lice in salmon farms. Spatial planning and siting models are being applied to minimize environmental footprint. Aquaculture also serves a restorative role, aiding the rehabilitation of marine and freshwater ecosystems and the reconstruction of endangered aquatic species populations. Technology has expanded cultivation into coastal marine waters and open oceans, responding to growing global seafood demand.