Trout in The Classroom - Norfork

The Norfork Elementary School has been part of our Trout in the Classroom program for a few years. Students released this year's batch on May 8, 2015. Here are the experiences of raising trout in a classroom from science teacher, Wade Geery.

Since we raised about seventy-five rainbow trout during 2014, I didn’t expect much difference this past year. Well, I was to learn much different.

I guess that the first clue was a larger than normal amount of eggs in our vibert box. When they had hatched, I estimated well over a hundred fry swimming in the aquarium.

All went well until just after Thanksgiving when I noticed a few dead fish around the water-circulating pump. The filter had clogged up a bit and I cleaned it and replaced about half the water in the tank with rainwater. Despite the chemical test kit that I had for ammonia-nitrates, the measurement was minimal. Just to be on the safe side, I purchased some ammonia removal tablets and dosed the tank.

Everything went well until the first week in February when another episode of fish dying was observed. I was surprised because I had been replacing twenty gallons or so of tank water with rainwater weekly. Observing the dead fish, my students noticed many fish “gulping” air near the surface, especially near the back corner where an under-gravel filter exhausted bubbles onto the surface of the water.  I suspected that the air pump was going bad so I dropped the water level allowing the circulating pump to spray over the surface and aerate the water.

I purchased another aquarium air pump, hoses, and bubbler rocks. When I set up the new air curtain, I noticed that the original air pump had a low/high electrical switch and the switch had been set to low all this time. When set to high it worked much better but I noticed the bubble vents in the under-gravel filter lines had been clogged with algae. I cleaned them out and dosed the tank with the recommended ammonia removal tablets.

It became a real chore to clean the circulating pump filter element weekly. I tried to locate a replacement filter element, but could not find one and never thought to ask you folks if you knew of a source.

Everything was going along fine until about the first of May, a week before we were scheduled to release the trout. The trout were really sluggish and stayed on the bottom a lot. The next day I noticed that they were not eating very well and several more were dead. Most of the fish, especially the smaller ones were very dark with white tips to their major fins. In fact, eight died on Friday with the students reporting the statistics hourly. I had exhausted the rainwater tank since it hadn’t rained for several weeks, so after school I brought twenty gallons of river water from the White River Access downtown. This helped somewhat, but by Saturday morning several more were dead. To make matters worse, I found one fish that had leaped out of the feeder opening cover overnight and behind the tank were eight others that had leaped out of the larger openings in the back.

I hauled forty gallons of river water, in two trips that day, and replaced the older water in the tank. On Sunday, there were no more dead fish and I continued making two more trips of about forty gallons of cold river water.

By Monday everything had stabilized. One thing that I noted was the extremely dark color of many of the rainbow trout. On Saturday I only counted three ‘green’ trout. The rest were darker, and most of them were so black that the juvenile spots were almost obscured. By Monday, most of the fish had returned to a green color and the number of ‘black’ fish reduced even further for the rest of the week.

Lessons Learned:
The ammonia-nitrate test kit at school was six years past the expiration date on the reagent tablets. I suspect that it couldn’t measure ammonia adequately. I need to get fresh reagents before next year.

I suspect that ammonia built up in the water and reduced the amount of oxygen that the water could dissolve. Even with 55 degree F water and a curtain of air released from two bubblers, the dissolved oxygen measured between 8.4 and 9.4 ppm. While that level is satisfactory. I would have expected it to be higher.

We released about eighty rainbow trout into the North Fork of the White River on Friday, 8 May 2015. They varied from four to five and a half inches long. There are still four rainbow trout in our tank at school and I plan to keep them there until school is over for the summer. I will release them and clean the tank in preparation for next year’s project.
Our largest fish was one that leaped out of the tank and was discovered desiccated behind the tank several days later. Even shrunken, it measured five and three-quarter inches long.

Despite our difficulties, Trout in the Classroom has been a resounding success. The students enjoy the fish, the fish provide a very real tie into aquarium life, and the excitement of releasing their trout into the river can’t be replaced with any number of ‘dry’ lessons. Thank you for all that you do to make Trout in the Classroom possible.

Wade Geery
Science Teacher, Norfork Elementary School