Harvest Sample
by Robert Kidd, Fish Culture Station, Saskatchewan Parks & Renewable Resources, Fort Qu'Appelle
A surprising number of fish are reared on the Saskatchewan Prairie. Annually over 800,000 fingerling rainbow trout are stocked in ponds and dugouts and grown to an edible size of 300-500 grams.
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The practice of dugout and pond aquaculture is simple. A suitable body of water is selected and in the early spring stocked with fingerlings. Fingerlings can be purchased from a broker or a private hatchery. Addresses of the nearest broker or hatchery can be obtained from local offices of the Department of Parks and Renewable Resources.
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Harvest Sample |
What makes a suitable body of water you may ask? There must be a high level of available oxygen, over 5 mg/L. The pond should be deep enough to maintain the oxygen levels and the temperature should stay below 25¯C. Extremely shallow ponds are not suitable for trout culture due to the possibility of summerkill. Depths recommended are generally over 3 metres but this depends on the amount of aquatic vegetation, cover, wind action, and fertility. The pH level should be below 9.0. The water body should have plenty of small crustaceans, insects and other aquatic organisms for food (most important is the freshwater shrimp Gammarus lacustris). Supplemental feeding may increase growth slightly but most fish farmers find the feeding expensive. Supplemental feeding may be necessary in newly excavated ponds as it takes about one to two years to establish a good supply of food organisms.
Fish are stocked in early spring. These grow over the summer and are generally harvested in the fall. Some farmers will harvest in the winter to avoid any possibility of getting "muddy" tasting fish. The number of fish stocked influences the size and number of fish produced. Stocking rates of 600-750 fingerlings per hectare produce good results. At this rate stocking a 6.0 cm fish can produce a 27.0 cm (350 g) fish by late October. Harvesting is most commonly done with 5.0 - 9.0 cm mesh gillnets. To select the right size gillnet, the mesh should allow only the head of the fish through the mesh. Angling is another popular method of harvesting.
An Aquaculture Licence is all that is required; this is available from your district Parks and Renewable Resources office. Contact your nearest office.
