Fisheries and Oceans Canada – Multi-Stress System

Fisheries and Oceans Canada – Multi-Stress System

Institution:
Location:	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;
Description:	Parameters Units Details 1 2 3 General Habitat insulated with sliding door x x x Photoperiod control (300 Lux @ 100%) x x x Manual, Astral & annual Rearing tanks x x x 6 x 9-L tanks, with lid and baffle Temperature control x x x 0.1-20°C ± 0.2°C in seawater. Central glycol Chilling system x Central glycol system on an additional 24’’x 48’’ shelving. Independent 500 w heater No. heater. Passive heat transfer from room warms water Static, dynamic x x x Dynamic mode while chilling water only– not while heating Minimum rate of change -0.3 °C/hour Maximum rate of change: x x x -3.5 °C/hour Precision x x x 0.2°C Water make-up x x x 0% – 100% of system volume/day Flow of make-up water x x x Approximately 150 L per day per unit Dissolved oxygen x x x Normoxia and hypoxia x x x >1.5 mg/L to near saturation Static and dynamic control x x x Air to by supplied on site by client x x x 0.8 Lpm @ 35 PSI per unit Nitrogen gas (98-100% purity) to be supplied by client x x x 0.8 Lpm @ 35 PSI per unit Maximum rate of change (dynamic/cyclic mode): x x x From 10 mg/L  to 1.0 mg/L in about one hour (at 10°C and 99% N2 purity) Precision x x x + 0.1 mg/l Nitrogen generator to create hypoxic conditions   Not included 100 psi Oil-free air to service the nitrogen generator   Not included Salinity x x x yes Static x x x Range 10-32 PPT Water to be provided by client Seawater and fresh water outlets pH x x x Static x x x Raised with air or a weak base; lowered with a weak acid or CO2 gas. Monitoring & control / high pH x x x Carbonate @ 42g/L Monitoring & control / low pH x x x HCL 0.5N & CO2 solution CO2 gas injection x x x Down to pH 6.0 CO2 gas requirements Supplied by client 0.4 Lpm at 6 psi per unit
Water recirculation level:	99.7% (1 water exchange/5 to 6 days);
Work done:	Conception Fabrication On-site assembling, commissioning and training

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.

Filtration 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.

Circulation Circuit

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.