Year-round low temperature control for the Aquatron Seawater Laboratory

The NSERC-supported Aquatron Laboratory at Dalhousie University is the largest university aquatic research facility in Canada. The facilities include six large tanks, including a 15 m diameter, 3 m deep pool tank and a 3 m diameter, 11 m deep pool tank, as well as a wide variety of smaller tanks, research spaces and equipment. Over the years, the Aquatron has supported national and international academic, governmental, and industry research across different disciplines, from fundamental science on the physiology of fish and bivalves to real world applications such as testing the effects of turbines on fish behaviour and developing techniques to improve culture practices of valuable species. The success of the Aquatron relies on the range of experimental conditions that can be manipulated and controlled in these facilities in order to test specific hypotheses. These controlled conditions allow for accurate replication of experiments and avoid the confounding effects of variables that cannot be controlled in field experiments. One of the key features of the Aquatron is that it can provide a stable supply of temperature-controlled seawater. Water temperature is key for marine life, affecting the performance of most species. The Aquatron Laboratory was designed with a series of heat exchangers and a chiller that can modify and control the temperature of the seawater that is directly pumped from the ocean; however, the main chiller is no longer functioning, which limits the capabilities of the Aquatron to run experiments in which low seawater temperature is a crucial variable. Given the need for controlled-temperature seawater, we request funds to purchase four compact chillers to substitute the old and damaged piece. Replacing the old unit with four compact chillers is not only economically sound, but provides greater versatility and risk management. The four independent small chillers will allow highly-adaptable configurations and will minimize the risk of total failure due to reliance on a single unit. The proposed equipment will be commonly used by at least 8 research projects, and will also remove technical barriers for further research. This improvement will guarantee the prolific training of high qualified personnel at the Aquatron, which has trained more than 76 students since 2012. Concluding, the proposed new chillers will provide the temperature-controlled conditions that are needed to perform experiments in low-temperature seawater, which will in turn guarantee the success of current and future experiments at the Aquatron Laboratory.