About
Established in 1985
Background
Scandinavian Silver Eel AB is a privately owned eel farm situated in Helsingborg, Sweden.
The farm started as a waste energy project in 1985 to exploit warm brackish cooling water pumped from Öresund (the sound between Denmark and Sweden). The quantities of water available meant that farming eels at 25C was an economically viable proposition because at this temperature the eels grow to consumption size within 2 years.
The results from the pilot plant operating during the period 1982-85 were very encouraging and led directly to the construction of our commercial plant. The plant became operational in the spring of 1986 and by 1988 Scandinavian Silver Eel had reached the production target of 100 tonnes of consumption eels per year.
Conversion to Recirculation
In order to compensate for a reduction in the amount of free energy available the existing farm farm changed from through-flow using brackish water to a recirculated system using freshwater. The initial step was to connect the fingerling unit (40 tanks, 2x2m) to a separate circulation system, where after leaving the tanks water is first mechanically cleaned using a drumfilter, then biologically cleaned and finally oxygenated before being pumped back to the fish tanks. sludge , feces and any feed waste collected during mechanical filtration can be used as a fertilizer, bio-energy or to the recipient. The biological filtration (nitrification) process occurs in concrete tanks filled with water and where small plastic rings are kept in motion by vigorous aeration.
After installing the recirculation system in the fingerling unit the growth and feed conversions were significantly improved despite having higher stocking levels.
the success of the trial recirculation system meant that a second system was installed for the on-growing unit (28 D-ended tanks, 3x11m). The standing stock now varies between 50 and 100 tonnes and the production of consumption eels is around 100 tonnes/year.