Aquaculture is the raising of marine animals in the water. It can take place in natural bodies of water such as ponds, lakes, marshes or brackish water and the ocean. It can also be done in man-made tanks, commonly found in fish hatcheries. Regardless of where it takes place, aquaculture has an impact on the environment locally and globally. To become an environmentally sustainable and economically sound activity, it is necessary to implement strict regulations on resource management and careful site selection. However, there is a natural alternative: aquaponics.
Aquaponics is the raising of marine animals in tanks or ponds using the water from the fish tank to grow without soil, vegetables, fruits or algae. It is a balanced closed system that recreates the same process we see in a natural pond where plants and animals thrive in perfect harmony.
Aquaculture faces some environmental challenges that aquaponics has solved naturally. I list these challenges below:
1. Management of effluents and waste.
The practice of Aquaculture necessarily includes waste management. The effluents from these farms include uneaten food, metabolic excretions, and feces. They are made up of both solid organic waste and dissolved organic and inorganic nutrients, which are discharged daily into the environment. The flux of these compounds should never exceed the natural assimilation capacity of the local ecosystem because severe impacts, such as eutrophication, oxygen depletion and alteration of local biodiversity, can occur both in the water column and in the bottom substrate. To replace the water discharged, it is essential to fill the tank with clean water. This implies extensive use of water resources.
In Aquaponics there is no waste. It is a closed and balanced ecosystem. What is considered waste in Aquaculture is a useful input for the balance between the needs of fish and the needs of plants. The bacterial colonies are responsible for the conversion of ammonia and nitrite into easily assimilable nitrogen by plants. Other potential participants are worms. They can break down solid waste from fish, excess roots, and other material shed by plants, making it more bioavailable to plants. As a result of these multiple natural filters, there is always clean water in the tank. There is no need to change and discharge the water into the natural environment. Less work for the farmer and no risk to the environment.
2. Origin and quality of fish feed.
In Aquaculture, usually the feed for farmed fish comes from fish in the ocean. This contributes to the overexploitation of the oceans. Another problem is that they are often pumped with hormones to promote rapid growth, and in some cases even given chemicals to change their color, such as synthetic astaxanthin or salmon to enhance the pink.
To preserve the health of the system and produce organic vegetables and fish, in Aquaponics the quality of food is a priority. Hormones and other synthetic chemicals are not allowed in this closed system: they directly affect the metabolism of plants. The diet of fish can be naturally supplemented by the introduction of a worm hatchery, black fly hatchery, or duckweed tanks to supplement high-quality commercial feeds that are often from plant protein sources (as has been proposed by the National Organic Standards Board, limit the amount of fishmeal and fish oil in organically certified aquaculture products).
3. Veterinary drugs.
In Aquaculture, like any factory farmed meat, the living conditions of the animals are not optimal and they are often kept alive through the continuous use of antibiotics. Furthermore, any medical treatment given to farmed fish poses a risk to the natural environment if the discharged water has not undergone adequate neutralization or dilution.
Antibiotics for fish are not allowed in Aquaponics because they can also affect the bacteria necessary for balance. High oxygen levels in aquaponics systems and worm activity help mitigate disease outbreaks in both fish and plants. In case there is a need to treat a particular disease, there is no risk of contaminating the natural environment.
4. Transfer of pathogens to wild populations
Aquaculture: With the need to drain water, there is a risk of pathogen transfer to wild populations.
Since Aquaponics is a closed system, any issues related to the health of the fish will be dealt with within the system. There is no risk of contaminating other species in nature. This automatically follows from local regulations that farmed species must not be released into the environment. Aquaponics is a balanced ecosystem that promotes health and vitality in both fish and plants.
5. Antifouling products
Antifouling products are necessary to prevent or minimize biofouling in aquaculture tanks. Biofouling is the gradual accumulation of organisms, such as bacteria and protozoa, on tank surfaces in contact with water.
Since biofouling is a natural process in a humid environment, in Aquaponics it is not necessary to get rid of microorganisms or algae. As an ecosystem, they are part of the living balance. For example, algae are a good food for some species of fish.
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Aquaponics, as we have seen, is a great option for those committed to sustainability, with the aim of securing the future of our planet. It is a technique that can be used indefinitely as an endless virtuous cycle that will allow organic harvesting all year round. In addition, it is an excellent option for those seeking efficiency and ease of operation on the path to food self-sufficiency.
If you are using aquaculture practices as a business or at home, take the opportunity to find out more about what Aquaponics has to offer!