Last Saturday, all of our 80,000 alevins, young salmon that still have their yolk sac attached, were moved from their rearing trays into holding troughs. In the holding troughs, our alevin are acclimated to the process of feeding before they are released into the rearing pond. The holding troughs are also used to check on their development process as they finish the process of “buttoning up”, which is where they lose their yolk sac from their bellies.
We had the Students Saving Salmon Club and other volunteers show up and help us with this large move for our small coho salmon. They are moved from the trays that simulate their natural environment with their meshed-made redds into the holding troughs by gently placing the tray into the trough, and are then allowed to swim outside of the only world they’ve known so far. After making sure all of the alevin have swam out of the trays, the trays are then rinsed off. In the holding troughs, our volunteers helped remove eggs that didn’t make it.
The water that flows into the troughs comes directly from Willow Creek, which provides the oxygen and clean water that young salmon vitally need. A cool thing to notice if you get to see them in their troughs is how they swim against the current. Salmon instinctively do this either because they get more oxygen since water is flowing directly past their gills or because this is how they feed by eating small zooplankton that are carried with the current.