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Cette This method consists in hiding in the gravel pits, of the type being appropriate for the salmon and trout spawning grounds, of small boxes out of plastic, "Vibert Boxes", of a capacity corresponding to a thousand of trout eggs. The perforations placed on the six sides of the box leave courrant it of water pore to bring to eggs the oxygen which is necessary for them. They make it possible alevins to leave themselves the box and to continue their development under gravel, under the natural conditions to which the wild alevins owe their rusticity. In a water pronfondor of approximately 30 cm, to dig a hole of approximately 20 cm of deep, to install the Vibert box and finally to cover with clean gravel until connection with the bottom in place of the river.
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Since 1920, in North America, the researchers carry out tests of repopulation starting from eggs placed under the gravels. The results are interesting. The major problem remained the handling of the boxes which obliged the intervention of four men.
The method of Richard Vibert takes again the same principle but improves it appreciably: the eggs are placed in a plastic box which it is easy to hide under the gravels. This box which weighs 45 grams is of modest size (70 X 63 X 45 mm). It is transported easily and contained a thousand of trout eggs. The perforations existing on the six faces let the current bring to eggs the oxygen which is necessary for them. They also make it possible alevins to leave themselves the box and to continue their development under the gravel, i.e. under the natural conditions to which they owe their rusticity.
To date, more than one million boxes were sold in the whole world. The Vibert boxes allow easy transport on long distances and under delicate conditions (in particular in high mountain). It is enough to find a gravel bottom in which one can place the box. The system is simple (it hardly asks handling), good market (the eggs are not very expensive) and effective. The hope of survival for alevins born in these boxes is quite higher than those obtained with the other means of repopulation. In the majority of the cases, the pisciculturist provides the boxes filled with eggs of repopulation quality to the purchaser. The eggs travel in isothermal packing containing of the ice. They support rather long transport perfectly. On arrival, the boxes are unpacked, they hardly contain dead eggs (white). Then the temperatures are balanced: inside packing the eggs are around 1°C, gradually one brings up them to the temperature of the river.
Simplest is to sprinkle them during a few minutes with the water of the river (attention not to expose eggs to the sun or freezing). Then it is enough with a fork to stir up the gravels of the bottom and to place the box inside the gravels. If the current is weak and the sandy bottom, a gravel monticule allows the hiding. One never should place the boxes on funds muddy or muddy, the eggs would be asphyxiated. A location of the points of hiding makes it possible to check, a few weeks later, the departure of alevins.
Vibert box type river.
Last Update: November 3 2004
Prices are in canadian dollars and can change without notice.