Many attempts have been conducted in order to keep C. finmarchicus in culture for multiple generations, e.g. at the Statoil Research Centre at Rotvoll in Trondheim. The success in establishing the culture at Sealab has been a continuous process with daily maintenance. Optimization of temperature, light regime, water quality and feeding has been the important parameters. The C. finmarchicus cultures were established in 2004 at Brattøra Research Centre during a project financed by the Norwegian Research Council (NFR 170429/S40). This project was a collaboration between NTNU (Department of Biology), Nordlandsforskning, SINTEF Materials and Chemistry (Marine Environmental Technology) and BioTrix. The cultures were established as copepodite stages CIV and CV which was collected with a Nansen zooplankton net in the Trondheim Fjord. Because the Brattøra Research Centre (NTNU) and SINTEF Materials and Chemistry were moved to SINTEF/NTNU Sealab, the cultures were moved in February and May 2007 to the new facilities at Sealab. The transport period required culture re-adaptation at the new location, and new cultures were established in two locations at Sealab (one at SINTEF and one at NTNU) in order to serve as backup-systems for each other.
A temperature-controlled room at SINTEF Sealab was dedicated for the Calanus culture. The temperature in the room was set at 10°C, and this the temperature was also used for most experiments. To simulate night and day conditions, light regulation is important for the cultures. Normally the cultures have a light:dark regime of 12:12 hours. The water used at Sealab is brought up from 90 meters depth in the Trondheim Fjord, is filtered through sand filters (70 µm), and pumped into polyester containers functioning as water reservoirs. The water is then aerated for two days in a tank with a bio filter. This “maturing process” of the water reduces negative effects of bacteria growth. The water is subjected to a final filtering (1μm) before use (Olsen et al., 2004).
C. finmarchicus feeds mostly on phytoplankton, and the cultures were continuously fed with a mixture of algae with a 1:1:1 relationship estimated on the basis of cellular carbon. Algae were cultivated in PET-bottles at 15°C in natural sea water filtered through 1 µm and sterilized by autoclaving in 15 min at 121°C. To stimulate algal growth nutrients (Conwy medium, Walne, 1974) were added at a concentration of 1 mL/L sea water. The compressed air was added 0.5-1 % CO2. The bottles were bubbled with continuously with air to keep the algae in suspension, and they received light through fluorescence tubes (2x Phillips TLD 36W 956) with an intensity of 100-120 µE sek -1m-2.
Published February 1, 2007
Calanus finmarchicus - a new and relevant test species for assessing effects of toxicants and climate changes in the marine environment.