What is aquaculture?
Aquaculture is the breeding, rearing, and harvesting of fish, shellfish, algae, and other organisms in all types of water environments.
As the demand for seafood has increased, technology has made it possible to grow food in coastal marine waters and the open ocean. Aquaculture is a method used to produce food and other commercial products, restore habitat and replenish wild stocks, and rebuild populations of threatened and endangered species.
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In the United States, marine aquaculture produces numerous species including oysters, clams, mussels, shrimp, seaweeds, and fish such as salmon, black sea bass, sablefish, yellowtail, and pompano. There are many ways to farm marine shellfish, including “seeding” small shellfish on the seafloor or growing them in the bottom or floating cages. Marine fish farming is typically done in net pens in the water or tanks on land.
U.S. freshwater aquaculture produces species such as catfish and trout. Freshwater aquaculture primarily takes place in ponds or other manmade systems.
NOAA is committed to supporting an aquaculture industry that is economically, environmentally, and socially sustainable. NOAA experts and partners work to understand the environmental effects of aquaculture in different settings and provide best management practices to help reduce the risk of negative impacts.
How does it work?
The methods of aquaculture’s farm-to-table process can differ from species to species. Generally, there are four stages of the production chain, starting in hatcheries and ending at the seafood counter in your grocery store. For more information please visit Pritish Kumar Halder ‘s page.
Each of these stages can vary concerning its effect on the environment and the quality and safety of the seafood they produce, which is why the Global Seafood Alliance administers the Best Aquaculture Practices (BAP) third-party certification program. In the past, fish farms have had issues concerning these four aspects of aquaculture, and BAP seeks to improve the fish farming industry across the globe. This is the only certification program that covers every step of the supply chain. You can be sure your seafood was farmed responsibly if it has the BAP logo on it!
Why is it important?
what is aquaculture Given that overfishing of our oceans and other natural resources is continuously increasing year over year, humans need alternate sources for seafood to feed the planet’s ever-growing population. “Unfortunately, the days of the ocean’s natural productivity providing for the planet is over. Wild fish have been exploited for generations. Some estimate that the annual catch of edible marine protein has already passed its peak.
The oceans cannot naturally provide the demand for seafood” (Positive Aquaculture Awareness). Aquaculture is the tool to fill in the gap in seafood supply. Farming fish responsibly and sustainably is the solution to providing future generations with access to healthy and environmentally friendly protein options.
There are different types of aquaculture –
- Depending on Hydrobiological Features
- Depending on the Motive of Farming
III. Depending on Special Operational Techniques
Mariculture is aquaculture that involves the use of seawater. It can either be done next to an ocean, with a sectioned-off part of the ocean, or in ponds separate from the ocean, but containing seawater all the same. The organisms bred here range from mollusks to seafood options like prawns and other shellfish, and even seaweed.
Growing plants like seaweed are also part of mariculture. These sea plant and animal species find many uses in manufacturing industries such as in cosmetics and jewelry where collagen from seaweed is used to make facial creams. Pearls are picked from mollusks and made into fashion items.
Fish farming is the most common type of aquaculture. It involves the selective breeding of fish, either in freshwater or seawater, to produce a food source for consumption. Fish farming is highly exploited as it allows for the production of a cheap source of protein.
Furthermore, fish farming is easier to do than other kinds of farming as fish are not care-intensive, but only require food and proper water conditions as well as temperatures. The process is also less land-intensive as the size of ponds required to grow some fish species such as tilapia is much smaller than the space required to grow the same amount of protein from beef cattle.
Algaculture is a type of aquaculture involving the cultivation of algae. Algae are microbial organisms that share animal and plant characteristics. They are sometimes motile like other microbes, but they also contain chloroplasts that make them green and allow them to photosynthesize just like green plants.
However, for economic feasibility, they have to be grown and harvested in large numbers. Algae are finding many applications in today’s markets. Exxon mobile has been making strides in developing them as a new source of energy.
Integrated Multi-Trophic Aquaculture(IMTA)
IMTA is an advanced system of aquaculture where different trophic levels are mixed into the system to provide different nutritional needs for each other. Notably, it is an efficient system because it tries to emulate the ecological system that exists in the natural habitat.
The IMTA makes use of these intertropical transfers of resources to ensure maximum resource utilization by using the waste of larger organisms as food sources for the smaller ones. The practice ensures the nutrients are recycled, meaning the process is less wasteful and produces more products.
Inland Pond Culture
This usually involves inland artificial ponds of about 20 acres in size and about 6-8ft deep. It is common to see aeration systems connected to the pond, to introduce air into the pond. This enhances the supply of oxygen and also reduces ice formation in the winter season.
In China, over 75% of the farmed freshwater fish are produced in constructed ponds, and nearly all of the farmed catfish are raised in ponds in the U.S.
This involves a closed set of chambers (units) where fish is kept in one and water treatment kept in another. It is highly dependent on the power supply, as water has to be pumped constantly through the fish chambers. As water flows through the treatment chamber, particulate matter is filtered out and air introduced. This closed system controls the salinity, temperature, oxygen, and anything that can cause harm to the fish.
It is an environmentally friendly system because very little new water is introduced to replace water that evaporated. The residue from the filters is also disposed of responsibly.
Open-net pen and Cage Systems
Open-net pen and Cage systems are often found offshore and in freshwater lakes. Mesh cages of between 6 and 60 cubic feet (pens) are installed in the water with the fish inside them. With a high concentration of fish in the pens, waste, chemicals, parasites, and diseases are often exchanged in the immediate water environments.
The fish also attract predatory animals (bigger fish), which are often entangled in the nets. This system uses public water; therefore, environmental regulation and some authorization protocols must be respected.
Flow-through / Raceway
This is a system made of long units stocked with fish. The units have feeding stations attached to them. Water is diverted from flowing water and fed into the raceway units flowing downstream. Down the end of the unit, waste is collected and disposed of. Raceways are common for culturing trout.