Main achievements during the project period
The project started in August 2009, and in December the same year we had our first CFC model tests at the facilities of GUT in Gdansk, where we tested for wave and current performance of different CFC shapes. This gave us vital input and narrowed down the number of possible cage designs.
Following the indicative results from the testing that was done in Poland we performed a second wave and current test in January 2010, this time in Bergen using a 1:10 scale model, and testing three different CFC designs. Observations and measurements from these trials strongly suggested that of our designs, the hemispherical shape was the most suited to withstand current and wave forces.
Following these tests, and a material selection process, we started the production of 12m in diameter prototype, and its supporting infrastructure and support systems. This prototype was finalised and installed at Norsk Havbrukssenter, Toft, Brønnøysund in Norway in September 2010. The location at Toft is classified as a Bc location according to NS 9415, which means that it is moderately exposed to waves, maximum height of 1.0m, and extensive exposure to current, maximum velocity of 1.0m/s.
The prototype has been in operation from September 2010 until June 2011, when we finalised the validation testing of the CFC system. During this time the system performed without problems. We also kept some hundred salmon in the CFC. They were introduced in October 2010 and taken out of the CFC in June 2011. At the same time Norsk Havbrukssenter were producing salmon, from the same batch as we had in the CFC, in three traditional open net cages, and during this period the fish in the net cages had to be treated for sea lice 2-3 times. The fish in the CFC system were all checked individually in June 2011, and not one single fish had sea lice.
Conclusions so far:
• The CFC system, as is, will withstand waves up to at least 0.5m and current speeds of 1.0 m/s
• The CFC system will contribute to reduce sea lice infestations, providing that the water source is sufficiently deep, at least -30m.
• The CFC system can be used to farm any species of fish, bar those that need a flat tank bottom to rest upon (i.e. Turbot).
• The CFC system will offer more stable conditions with regards to O2, compared to open nets.
There is still some work remaining with up scaling the CFC system to a commercial size, of at least 70m circumference, but with the knowledge we now possess as a result of this project we are confident that a commercial scale system will see the light in the near future.
