Aquaponic systems: Potentials on a northern latitude
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Aquaponics is a food production method that combines hydroponic and aquaculture to form a system that, through symbiosis, re-circulates all the water and nutrients – and thereby negates any discharge of eutrophied or contaminated residuals – in order to grow terrestrial plants and aquatic life. To study the possibilities of aquaponics at northern latitude, a small scale aquaponic system was constructed in Jämtland, a county in the Mid Sweden region (latitude 63°) and studied while running over a nine month period, August 2012 to April 2013.
The fish species grown in the fish tank was a species of trout prominent in local lake and stream fauna. The plants in the growbed were a mixture of different flora with herbs as a dominating part. Water from a local groundwater well was used. At start, appropriate nitrogen level in the system was achieved by adding ammonia. The values of nitrate, nitrite, pH, carbonate and total hardness were analyzed in repeatedly measured samples. The values stabilized quickly and stayed stable over the duration of the experiment. Heavy metals were analyzed at one point in time and showed no levels causing reason for alarm. Electric energy use for pumps and lighting was measured to reach close to 40 kWh per month.
The trout growth was monitored and found to be comparable with (equal or slightly higher than in) the conventional aquaculture where the fish were originally obtained, when comparing with the same species and same brood. Among flora three herbs were the species thriving best, Oregano, Rosemary and Thyme. They kept growing throughout the winter with Oregano never ceasing to bloom. The total mass of produced vegetables and herbs were fairly low, since the herbs grew best. Results indicate that present aquaculture systems (fish only) could potentially be converted or adjusted into aquaponic systems (recirculating and purifying the water through a growbed) and thereby decrease potential risks of fresh water pollution from fish farming, especially regarding excessive nutrients.
From the results in this study it seems aquaponic systems on northern latitudes are more favorable if focusing on fish growth, with herbs or vegetables as added benefit, and not focusing on maximizing vegetable growth. Continued studies would do well to investigate optimization parameters through, for instance, mass balance calculations and to identify optimal mixtures of plants over the year.
Place, publisher, year, edition, pages
2013. , 29 p.
Aquaponic, Aquaculture, Growbed, Biodiversity, Trout growth, Fish tank, System analysis, Closed loop
IdentifiersURN: urn:nbn:se:miun:diva-19462OAI: oai:DiVA.org:miun-19462DiVA: diva2:633765
Subject / course
Ecotechnology and Environmental Science
Ecotechnology NEKOG 180 higher education credits
2013-06-03, Q221, Akademigatan 1, Östersund, 10:15 (English)
Fröling, Morgan, Assistant professor