We collect live Antarctic krill using a unique 'wet well' within our research vessel RSV Nuyina. Once aboard, the animals are kept alive in containerised aquaria until the ship returns to Hobart. They are then transferred to the land-based aquarium at headquarters.
Unlike a usual low temperature research facility that cools the whole laboratory to control the water temperature of the tanks, the aquarium is a recirculating sea water system in which the water is chilled directly.
- The air is kept at about 18°C and scientists can do their experiments without wearing freezer suits.
- Heat exchangers maintain the water in the tanks typically at 0.5°C although temperatures as low as −1°C can be reached.
- The water is recirculated continually at up to 1.5 litres per second. It passes through a group of filtering units with the whole system volume of the main holding tanks (approximately 8,000 litres) being filtered every 90 minutes.
Most of the krill are kept in this system. They are fed different types of live and dead phytoplankton and microencapsulated vitamins and minerals. The tanks get a typical Antarctic photoperiod (number of hours of daylight) to copy the lighting conditions that they would receive in the Southern ocean.
In addition to the 8,000 litre system, there is a separate experimental system of approximately 24,000 litres. This can be used to change water chemistry, temperature and lighting for a wide array of experiments. Some experiments involve short-term measurements and observations while others are longer term studies that may require rearing krill through several years.
Our research capabilities have been enhanced by our success in getting wild krill to school and reproduce in the aquarium. Antarctic krill kept in the aquarium mature, mate and spawn as they do in the wild. Their larvae survive and reproduce themselves. This achievement allows us to study their early life stage in detail, which is key to understanding their survival through the harsh Antarctic winter condition.
Our research provides a greater understanding of how krill contribute to the Southern Ocean ecosystem. Research performed in the aquarium is published in international peer reviewed scientific journals and as documents for the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).
