Today (5/2/2011), we loaded our 25 fingerling trout into a specially rigged cooler for a trip to South Mountains State Park in Burke County, NC. We added two 2-liter bottles of frozen water (to keep the temperature in the 50′s) and an aerator (to keep the water oxygenated) so the fish would survive the almost two hour drive.
Our trout transport tank
It was a beautiful morning to release our trout. None of the students had been to this state park, and they were excited to see it. We parked along the Jacob Fork River, and transferred our trout into two small buckets.
Transporting the trout to the river
We found a clear, shallow area and set them free…check out these two 30-second video clips (each shows the trout swimming free underwater):
After watching our fingerlings swim off, we had a picnic lunch in the sun. Then, we tried a little “stream sampling” with our flyrods…
The perfect school day?
*Thanks to everyone who helped us this year, but special thanks to Jim Mabrey of the Rocky River TU Chapter)!
We just got the stocking permit to let our fish go in the Jacob Fork River (Burke County, NC) within South Mountains State Park. We plan to let our fish go on Monday, May 2nd. We will try to broadcast the release live on UStream if we have a good signal.
So, it has been a good while since I’ve posted anything new. We still have about 25 healthy fingerling trout. We still hope to release them around the first of May in a NC mountain stream. More pictures to come soon…
We are back in school, and our parr are thriving. We’ve had no more losses since early November. The largest of our 25-27 fish are about 2 inches now. Mrs. Reid’s 1st grade class has been up to visit them several times now, and we have had some great question and answer sessions about fish development and physiology.
If you just stumbled onto this blog, you may wonder why we are raising cold-water fish in classroom. Maybe this will help…
One of our class members is an avid fisherman, and over the holidays he sent me this picture of a nice catch in the Green River:
Green River Rainbow
In a few months we will release these fish into a mountain stream. Hopefully most of them will survive and some of them will end up in the hands of fisherman. Why raise fish to catch fish? There are many good reasons, but one is to avoid the Tragedy of the Commons. Garrett Hardin coined this phrase in 1968 for situations in which individuals ruin a public resource due to self-interest (greed). It is hard for any fisherman to know how many fish are in the river, so the State of North Carolina sets creel limits and stocks streams. We got the eggs for this project from a state hatchery. So, this is really a conservation project–it is about trying to prevent the ruin of a resource.
Well, it has been about 10 weeks now since these trout arrived. The fish now have 6-8 dark bands on each side called parr marks, and are now called parr instead of fry. These bands may have some function as camouflage for the young fish in the wild. Although the picture below is a bit fuzzy, you can see these marks on some of the larger fish in the foreground:
See the stripes?
I have read that the parr marks tend to disappear after the first year–notice the adult rainbow trout at the top of the web page does not have them.
If you look carefully, you can also get some sense of the genetic variety in these fish. The largest of the parr are about 2 inches, and the smallest around half that. As the fish get larger and hungrier, I imagine we may start to witness some cannibalism. Last year we saw the larger fish eat a few of the smallest ones!
Well, after our incident with the filter we lost about 30 more fish. Even though we saved some fish from the filter, many of them still did not learn to eat the fish food and ended up dying on the bottom of the tank like these (can you see them?):
The Unfortunate Ones (click to enlarge)
All together, we are down to about 25 fish in the tank. That is probably a good number for our 55 gallon tank. If we have too many, their waste will build up and kill many fish. It was great to have Mrs. Reid’s 1st grade class pay a visit to our survivors last week. Here is a picture of the kids and I discussing the trout tank:
Ok, so last week a student noticed that if we had 60 fish to start with, that about half seemed to be missing…that’s a lot of fish.
So, we pulled apart the canister filter on the system
Canister Filter (disassembled)
and this is what we found:
Bucket Full of Fish!
So, there were about 40 very stressed out little fish in the bottom of the filter! These were the tiniest fish who were not strong enough to swim away from the powerful suction of the pump intake pipe. These fish would probably be most likely to be caught by predators in the wild. Of course, we prefer not to loose any fish. We put them all back into the main tank and added a net bag over the filter intake pipe. This should prevent any more fish from being sucked in to the filter unit. Over the weekend we lost about 25 of the 60 or so fish we think we started with as many of those tiny fish just could not recover from a few days in the bottom of the filter with no food. It is critical to get the dead fish out of the tank as soon as possible as their decomposing bodies can create other problems in the tank…more on that later…
Our trout are feeding and growing rapidly. They are only about an inch long, but that seems like they have almost doubled in length in the last two weeks.
Tiny Fry
We were given a small bag of “trout chow” to feed the trout. Here is a short video of them feeding at the surface:
For some strange reason, we are missing about half the trout we started with. I’ve got a sneaking suspicion that they have been sucked into our filter system. Check back soon to found out…
When we walked in this week, most of the trout had used up their yolk sacs and were swimming well in the egg basket. We have been sprinkling “trout chow” in each day, trying to get them to learn to feed. By the end of the week (today), 99% of the fry were swimming strongly in the basket, so we let them out of the egg basket to swim freely in the tank. Check out this short video of the release:
The fish darted around the tank exploring its limits, but by the end of the day they were starting to school together in the currents. Unfortunately, not all of our fry made it to this free-swimming stage. About 5% of the population had some form of genetic defect. The most common defect was a curved spine. Fish like the ones in the short video below would never be able to swim efficiently, so they would starve and die.
Come back next week and check in on our little friends!
