Spawning the imagination Students get lively view of science from fish biologist

Grade-school students gathered around bubbling tanks in the St. Regis science classroom as Brooks Sanford dumped about 250 of squirmy orange alevin into the water from a net container. Alevin are newly spawned trout still carrying their yolk sac. Some students squeal with delight as they drop down into the pea gravel below.

He explains that it will take 10 days for them to absorb the tiny orange sacs. After that stage, high school students taking his aquatic science class, will split the tiny minnows up into two groups. The groups will have different feeding regiments and different water temperatures, “we will be studying those effects on growth rate,” explained Sanford.

This is his second year as the school’s science teacher and has previously worked in a fish hatchery. He got the fertilized eggs from the Jocko River Trout Hatchery in Arlee and it took 30 days for them to hatch. Once the trout have grown, they will be released in the pond at St. Regis park.

Prior to the fish being released, his class will work with Montana Fish, Wildlife & Parks on a restoration project for the pond. They plan on dredging it out and will install aerators and docks. All with the hopes that the fish will survive in the half acre pond when released next spring.

The class is an elective course and in it students learn about fish ecology, biodiversity, and fishery management. It’s been popular so far, with 15 students signed up. Brooks stands in front of a black box which looks like a computer hard drive, “this is a chilling unit that’s pumping water which mimics a river system. It keeps the water at a constant 52 degrees, which is optimum for trout growth. It acts like an air conditioner.”

In the wild, fish normally spawn in the spring. The female will dig a nest called a redd and lay her eggs in the depression. Then the male fertilizes the eggs and the females comes back and pushed the gravel over them. The alevin hatch under the gravel and don’t pop from under it until their egg sacs are gone.

Brooks said the Arlee hatchery has developed a strain of rainbow trout that spawn in late October to December. They took a McCloud strain and a Donaldson Strain, and collected late spawners.

Those were bred together and then they took their offspring and repeated the process until they got a strain that spawns later. This was done so the hatchery trout can be raised over the winter and are the right size to be released when fishing season begins in May.

Otherwise, if they took a Shasta Rainbow that spawns in June, they would have to raise it over the winter and that costs more money. The hatchery fish are approximately four to six inches when released.

Most of the classroom fish will be released next spring; however, a few will be kept in the giant tanks that line the room for further study. If people want to watch the progress of the program, Sanford is posting videos on the schools website at www.stregisschool.org/domain/105.