Fisheries and Oceans Canada – Multi-Stress Systemtony
Winnipeg, Manitoba, Canada
|Contact:||Dr. David Deslauriers|
|Central & Arctic Region, Freshwater Institute|
|Arctic and Aquatic Research Division|
|Equipment:||Three Multi-Stressor Units|
|Habitats:||Fresh water & Seawater;|
|Temperature:1||0.1° to 20° C;|
|Water recirculation level:||99.7% (1 water exchange/5 to 6 days);|
Fisheries and Oceans Canada – Multi-Stress System
A Multi-stressor rack is composed of up to three independent water recirculating systems, one per shelf. Each system includes a Habitat Module (zebrafish tanks & plumbing for water inflow/outflow), and a Filtration Module (biofilter, cartridge filter, heat exchanger, controls) located on an adjacent rack). On each shelf runs a row of LEDs controlled by the Enviro-Monitron.
The Habitat Module is enclosed into opaque insulated cabinet to protect the animals for ambient room lighting and reduce chilling requirements. This unit is made to accommodate hypoxic control, as well as creating normoxic and hyperoxic conditions. The Multi-stressor components are illustrated in the figures below.
Fisheries and Oceans Canada – Multi-Stress System : Flow circulation
The water flow through the unit is divided into two circuits, the Filtration circuit and the Circulation circuit.
From the sump tank, the water is pumped through the 20 microns cartridge filter and the activated carbon filter. From the activated carbon filter, the water flows through the chiller & heater, the biofilter and trickles down back to the sump.
The water coming from the biofilter is collected in the sump and then is pumped directly to the rearing tanks. The effluent from each of the rearing tanks flows along a gutter and then back into the sump tank.
A double hydraulic circuit assures a constant flow to the rearing tanks, regardless of filter clogging.
Fisheries and Oceans Canada – Multi-Stress System : Temperature control
The cooling and heating capacity of the unit was factory-tested in salt water. A minimum temperature of 1°C and a maximum of 30°C were obtained in salt water (room temperature at 20°C).
Without cooling or heating and a room temperature at 20°C, the balanced temperature of unit 2 is 23.2 + 0.1°C and unit 3 is 24.5 + 0.1°C. This temperature is higher than room temperature due to the heat transfer from the pumps to the water. Therefore to obtain a cooler temperature than these balanced values, the chiller must be operated. Likewise to obtain a warmer temperature than these balanced values the heater must be operated.