Land-based aquaculture is the practice of farming aquatic animals like fish and shrimp in controlled facilities on land, using tanks or ponds instead of traditional net pens in natural bodies of water. These environments are designed to optimize conditions for the health and growth of the species being farmed to help meet the rising global demand for seafood.
Land-Based Farming Systems
The most prominent technology is the Recirculating Aquaculture System (RAS). These systems link holding tanks to water treatment units, continuously filtering and reusing the water. This high degree of control allows operators to manage nearly every aspect of the aquatic environment to optimize growing conditions.
A RAS facility functions through a sequence of filtration processes. The first step is mechanical filtration, where heavy solid wastes are removed from the water, often using drum filters with fine mesh screens. Removing these solids early reduces the strain on subsequent filtration stages.
Following the removal of solids, the water undergoes biological filtration. This stage addresses dissolved chemical wastes, primarily ammonia, which is excreted by fish and is toxic in high concentrations. Biological filters cultivate beneficial bacteria that perform nitrification, a process that converts ammonia into nitrite, and then into the much less harmful nitrate.
After biological treatment, the water is re-oxygenated and can be temperature-adjusted before it is recirculated back to the fish. This constant cycle ensures stable water quality. The complexity of these systems requires skilled personnel to monitor and maintain the delicate balance of the farm’s internal ecosystem.
Species Suitable for Land Farming
Several aquatic species are strong candidates for land-based farming due to their biological traits and market demand. Atlantic salmon is a leading species for RAS facilities, driven by its high market value and the ability to control its entire life cycle in a contained environment from egg to harvest.
Shrimp are another prime candidate for land-based systems. They can be grown at very high densities, making them economically viable for the high-investment cost of RAS facilities. Their tolerance for controlled environments and rapid growth cycles allow for consistent, year-round production.
Other species, such as Barramundi (also known as Asian sea bass) and Yellowtail, are increasingly farmed on land. Barramundi is known for its hardiness and rapid growth in warm water conditions that can be easily maintained in a tank environment. Yellowtail is a high-value species popular in sushi markets.
Environmental and Locational Considerations
A primary driver for adopting land-based aquaculture is its environmental profile. Because these systems are enclosed, they allow for the collection and treatment of fish waste. The solid waste, rich in nutrients, can be captured and repurposed as fertilizer or for bioenergy production, turning a potential pollutant into a valuable byproduct.
The enclosed nature of these farms also provides a high level of biosecurity. Water entering the system is disinfected, which reduces the risk of disease outbreaks and minimizes the need for antibiotics. The physical separation from natural waterways eliminates the possibility of farmed fish escaping and interacting with wild populations.
Land-based systems also offer locational advantages. Since they are not dependent on specific coastal areas, these farms can be constructed almost anywhere, including inland locations. This flexibility allows facilities to be built near major urban markets, reducing transportation costs and the associated carbon footprint while delivering a fresher product.
Global Implementation and Scale
Land-based aquaculture is becoming a commercially significant industry, with large-scale projects emerging worldwide. The implementation of these farms is notable in regions aiming to increase food security and reduce reliance on imported seafood.
North America has become a hub for development, with major investments in states like Maine and Florida for large Atlantic salmon farms. In Europe, countries with long histories of aquaculture, like Norway and Denmark, are also embracing land-based RAS technology. The Middle East is another region investing in this technology to overcome arid conditions and produce fresh seafood locally.