Last week we received our rainbow trout eggs from the Oregon Dept. of Fish and Wildlife. The eggs originated from the Roaring River fish hatchery near Scio, Oregon. It did not take the eggs long to hatch. We were greeted this morning with two incubators full of 500 smiling alevins (trout with egg sacs attached) and all seem to be doing well. Over the next month students will study how trout (and other organisms) survive in ecosystems as how organisms’ external structures their functions help aid survival. More pics coming soon!
Our alevin friends have grown a bit since the last video clip. All along, we have been learning about salmon survival rates, external features, and life cycles. Students have started research about salmon species will be writing reports after Thanksgiving break. In December we have some exciting plans regarding learning about stream surveys and stream engineering as well as releasing our finned friends.
All of our eggs have hatched in both of our incubators. Our students have noticed that the alevins behave differently between both incubators as one has more gravel spread out than the other.
Some salmon eggs in both of our classroom incubators are beginning to hatch. Take a look at a few of our new alevins!
Here’s an aerial view of our trout, which are now in the alevin stage. The hatched trout now have an egg sac attached to their undersides. It is their source of nourishment for the next few weeks until they are ready to be released.
Our chinook salmon alevins are growing fast and they’re making good progress with their swimming lessons. We’re looking at releasing them sometime during the week of December 16th as they transition to the fry stage. More information will be forthcoming regarding when and where we will release them, as well as a request for some parent help at the release site.
Here is the latest video update of how our chinook salmon alevins are developing.
Our chinook salmon alevins are starting to become quite busy in their little worlds. Activity is increasing everyday in both incubators. Ammonia levels have been a concern so we have changed out the water several times. Thanks to Mr. Segundo who has hauled in numerous five gallon buckets of water from our well pumphouse on several chilly mornings. You will note a clearing in the rocks. This is where we dumped in the new water from the buckets. It is interesting to see how the salmon alevins react to it. Stay tuned for more developments!
This morning we were greeted by about 1,000 wiggling chinook salmon alevins in both classroom incubators combined. Over the weekend all of our eggs hatched. When the eggs hatch, it is common to find a white frothy foam on the surface of the water and to have the water a bit cloudy. This is caused by the egg yolk residue mixing with the water. As a result, the ammonia level in the incubators usually climbs to dangerous toxic levels. To remedy this, we change out half or more of the water to dilute the ammonia. The incubators also are equipped with ammonia filters, but it often isn’t enough to keep the level down once they hatch. You will notice the alevins have very large yolk sacs. These are the food sources for the young salmon until the sacs become used up and the fish become free-swimming fry. Stay tuned for more updates!
On Tuesday our trout eggs hatched. Thus far the egg mortality has been one egg out of about 1,000 between our two incubators. The trout are in the alevin stage which means they currently have egg sacs attached to their undersides for nourishment. The alevins are very light sensitive right now, and to accomodate this, our incubators are covered with laminated tagboard. Our students in teams of two are testing the incubators for ammonia and pH levels as well as recording temperature data and observations. Stay tuned for more fishy developments.