Aquaponics has arrived at The Walled Gardens of Cannington
The new Aquaponics Centre, in the Botanical Glasshouse, has been constructed by Fisheries and Horticulture students from Bridgwater College’s Cannington Centre, and represents an exciting step into the specialised world of raising fish and food in a closed system.
Aquaponics works by using the waste created by fish to feed plants via a filtering system that constantly recycles the water. The secret to success lies in the presence of microbes which convert the fish waste into usable plant nutrients. The Gardens’ system comprises of a 200 litre base tank and an 80 litre grow bed, and can grow up to 15 different salad plants at a time. During 2015 large quantities of lettuce and other leafy crops were successfully grown and used within the Gardens’ Tea Room, in addition to peppers and aubergines. Now the Aquaponics Centre is complete, this year’s plans include a wider variety of crops, and the current most popular is spicy watercress.
The Aquaponics Centre houses Nile tilapia Oreochromis niloticus, a tropical species that prefers to live in shallow water. They are distributed in Africa, naturally occurring in coastal rivers of Israel, Nile basin, Jebel Marra, Lake Kivu, Lake Tanganyika, Awash River, various Ethiopian lakes, Omo River system, Lake Turkana, Suguta River and Lake Baringo. In West Africa natural distribution covers the basins of the Senegal, Gambia, Volta, Niger, Benue and Chad, with introduced specimens reported from various coastal basins.
The fish are mainly diurnal, active during the day, their preferred temperature for optimum growth ranges from 31°c to 36°c, however they can tolerate temperatures between 11 –
12°c and 42°c. Nile tilapia is an omnivorous grazer and can filter feed, although its main source of nutrition is obtained by surface grazing. Nile tilapia can live longer than 10 years and reach a weight exceeding five kilograms, with males growing faster than females. Already the fish have settled down in their new environment producing a large quantity of baby fish during the recent weeks. The climate control in the Botanical Glasshouse ensures optimum conditions for the fish.
Both fish and food will be used in Bridgwater College’s catering facilities in the future, ensuring a regular source of fresh produce can be enjoyed by visitors and students alike. For students in Fisheries and Horticulture, this new facility provides an excellent opportunity to develop the skills needed for employment in a range of industries.