Aquaculture is the farming of marine animals in water. It can take place in natural bodies of water such as ponds, lakes, swamp or brackish water and the sea. It can also be done in artificial tanks commonly found in fish hatcheries. Regardless of where it takes place, aquaculture has local and global environmental impacts. Becoming an environmentally sustainable and economically sound activity requires strict resource management regulations and careful site selection. However, there is a natural alternative: aquaponics.
Aquaponics is the breeding of marine animals in aquariums or ponds that use the aquarium water to grow without soil, vegetables, fruits or algae. It is a balanced closed system that replicates the same process we see in a natural pond where plants and animals thrive in perfect harmony.
Aquaculture faces some ecological challenges that aquaponics has solved naturally. I list these challenges below:
- Sewage and Waste Management.
The practice of aquaculture inevitably involves waste management. The waste water from these farms includes uneaten food, metabolic waste and faeces. They consist of both organic solid waste and dissolved organic and inorganic nutrients that are released into the environment on a daily basis. The flux of these compounds should never exceed the natural assimilation capacity of the local ecosystem, since serious impacts such as eutrophication, oxygen depletion and alteration of local biodiversity can occur in both the water column and the soil substrate. To replace the drained water, it is imperative that the tank be refilled with clean water. This involves extensive use of water resources.
There is no waste in aquaponics. It is a closed, balanced ecosystem. What is considered waste in aquaculture is a useful input to the balance between the needs of the fish and the needs of the vegetables. Bacterial colonies are responsible for converting ammonia and nitrite into nitrogen that can be easily taken up by plants. Other potential participants are worms. They can break down solid waste from fish, excess roots, and other materials that plants shed, making them more bioavailable to plants. As a result of these numerous natural filters, there is always clean water in the aquarium. There is no need to change the water and discharge into the natural environment. Less work for the farmer and no risk for the environment.
- Origin and quality of feed for the fish.
In aquaculture, the food for farmed fish generally comes from fish found in the sea. This contributes to overfishing of the oceans. Another problem is that they’re often pumped with hormones to encourage rapid growth, and in some cases even given chemicals to change their color, like synthetic astaxanthin to salmon to intensify the pink.
To maintain the health of the system and produce organic vegetables and fish, food quality is paramount in aquaponics. Hormones and other synthetic chemicals are not allowed in this closed system: They interfere directly with the plants’ metabolism. The fish’s diet can be supplemented naturally with the introduction of a worm farm, blackfly farm, or duckweed tanks to supplement high-quality commercial diets, often derived from plant-based protein sources (as suggested by the National Organic Standards Board). Limiting the amount of fishmeal and fish oil in products from organically certified aquaculture).
- Veterinary medicinal products.
In aquaculture, as with any meat from factory farming, the living conditions of the animals are not optimal and are often kept alive through the continuous use of antibiotics. In addition, any medical treatment of farmed fish poses a risk to the natural environment if the water discharged is not sufficiently neutralized or diluted.
Antibiotics for fish are not allowed in aquaponics as they can also affect the bacteria necessary for balance. The high oxygen levels in aquaponic systems and the activity of the worms help mitigate disease outbreaks in both fish and plants. If a certain disease needs to be treated, there is no risk of contaminating the natural environment.
- Transmission of pathogens to wild populations
Aquaculture: Due to the need to drain the water, there is a risk of transmission of pathogens to wild stocks.
Since aquaponics is a closed system, all fish health issues are dealt with within the system. There is no risk of contaminating other species in the wild. This follows automatically from local regulations which state that cultivated species should not be released into the environment. Aquaponics is a balanced ecosystem that promotes the health and vitality of fish and plants.
- 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 the surfaces of tanks that come into contact with water.
Since biofouling is a natural process in a humid environment, there is no need to get rid of microorganisms or algae in aquaponics. As an ecosystem, they are part of the living balance. For example, algae are good food for some species of fish.
Aquaponics, as we have seen, is a great option for those who are committed to sustainability and aim to secure the future of our planet. It is a technique that can be used indefinitely as an endless virtuous cycle that allows for an organic harvest all year round. In addition, it is an excellent choice for those seeking efficiency and ease of use on their way to food self-sufficiency.
If you use aquaculture practices for business or at home, take the opportunity to learn more about what aquaponics has to offer!
Thanks to Martha I Mc Kelligan
