Raising trout from eggs to fry in the classroom is a fabulous way for students to observe and study the life cycle of vertebrates and simultaneously learn about threatened species in local watersheds. Many states have programs where teachers and students raise trout in their classrooms in partnership with the Department of Fish and Wildlife for later release into a designated lake, creek or river. Described here is information for teachers on how to partner with state agencies, fish hatcheries, and local fly-fisher groups to raise rainbow trout in the classroom. A worksheet for the trout release field trip is provided. Best of all, many Trout in the Classroom Programs are fully supported by local fly-fisher groups and the California Department of Fish and Game (such as the California program that I participated in), and thus there is no materials cost to the teacher beyond the costs of organizing the trout release field trip at the end of the project.
Steelhead/rainbow trout (Oncorhynchus mykiss)
30 min set up tank
1 week for tank to equilibrate
1 month (approximately) between fertilization and hatching
2-3 weeks from hatching to release
Time required for the trout release field trip varies depending on the distance from your school and desired activities at the release site.
The raising and care of the fry takes place as a whole class. During the trout release field trip, students may collect data in groups of 4 students.
Trout or salmon eggs are provided by your state’s Department of Fish and Wildlife, often through a local fish hatchery. Usually, a training workshop is required to participate, and a permit to transport and rear eggs is required from the state.
Aquarium set up (many state agencies and their partners offer the following equipment for classroom use for free):
1 10 gallon aquarium tank
1 undergravel filter
1 pump for undergravel filter (such as the Powerhead 201 pump from Hagen Aquaclear, available at most aquarium stores for $15-20)
Pea gravel, enough to cover the bottom of the aquarium to a depth of 1 inch
1 aquarium chiller or refrigeration unit that can maintain a 10 gallon tank at a stable 50°C (try the Cool Works Ice Probe Model IPWC-50W and power supply Cool Works P/N 5239, available at specialty aquarium supply companies for $100-120)
Aquarium thermometer that can monitor 1°C intervals between 40-60°C
10 gallons of non-chlorinated spring water
Turkey baster (for siphoning away unhatched eggs
Aquarium insulation (make a Styrofoam box to surround your aquarium using insulating Styrofoam sheets available at most hardware stores)
Optional: if not using insulation, you will need a heavy black cloth to protect the alevins from UV radiation
For water testing
Dissolved oxygen test kit (see Water Analysis lesson for sources)
pH test strips
Trout are raised in the classroom then released on a field trip to a local lake, creek or river.
Raising trout provide a fabulous way to introduce students to the life cycle and physiological requirements of other species. Moreover, you can use these fish to teach students about threatened and endangered species.
Oncorhynchus mykiss (rainbow trout or steelhead trout) are the most commonly encountered species in classrooms. They are native to the West coast of North America but have been introduced to oceans, lakes and rivers world wide. They are a highly prized game fish in many North American rivers.
They belong to a class of fish known as salmonids that includes salmon and trout. Salmonids are anadromous, that is, they are born in fresh water but may spend much of their adult lives in the ocean, returning to the rivers in which they were born to spawn and lay their eggs. The freshwater form of Oncorhynchus mykiss is called rainbow trout. These fish may spend their entire lives in fresh water. The saltwater form is known as steelhead trout. These are generally larger than rainbow trout and can find their way back to the stream of their birth to spawn and lay eggs. Steelhead are then able to migrate back to the ocean and repeat the cycle several times in their life. Salmon, the other genus of salmonids, die after spawning and do not return to the ocean. For more information on the trout life cycle, see the Nevada Trout in the Classroom website.
Each of these factors (besides the food supply since the alevin will have a yolk sac while in the classroom) must be carefully recreated in the classroom aquarium. Steelhead are classified as a threatened species since water diversion (dams), migration barriers (culverts, roads, and walls), habitat destruction, introduced species and creek disturbances (pollution, trash, dogs, erosion, etc.) have dramatically reduced the amount of acceptable habitat.
Different parts of the country have different programs for teachers to raise salmonids in their classrooms, each with its own set of rules and regulations. See the Procedures below to get in contact with a program near you. Information on how to set up a tank and care for your fish can be downloaded from Trout Unlimited. Curriculum resources may be downloaded from the Nevada Department of Wildlife.
To start a Trout in the Classroom program at your school, contact your state’s Department of Fish and Wildlife or find a local chapter of Trout Unlimited. These agencies sponsor training programs for teachers to show them how to set up an aquarium, get eggs, raise the fry, and release them into designated ecosystems. For specific resources, see the list of selected programs below:
On your trout release field trip, organize students into groups and assign each group an area of the creek, stream or river to survey. Groups are responsible for collecting data about the quality of the habitat and whether the newly released trout will have what they need to survive. Gather data on factors such as temperature, dissolved oxygen content, pH, shade, cover, and food availability. See the Water Analysis activity or the Habitat Survey activity or the Sediment Study project for details. A handout is provided but should be adapted to your specific release site.
Ecology (Life Sciences)
5. Organisms in ecosystems exchange energy and nutrients among themselves and with the environment. As a basis for understanding this concept:
a. Students know energy entering ecosystems as sunlight is transferred by producers into chemical energy through photosynthesis and then from organism to organism through food webs.
e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition.
1. All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope. As a basis for understanding this concept:
f. Students know that as multicellular organisms develop, their cells differentiate.
2. A typical cell of any organism contains genetic instructions that specify its traits. Those traits may be modified by environmental influences. As a basis for understanding this concept:
a. Students know the differences between the life cycles and reproduction methods of sexual and asexual organisms.
3. Biological evolution accounts for the diversity of species developed through gradual processes over many generations. As a basis for understanding this concept:
a. Students know both genetic variation and environmental factors are causes of evolution and diversity of organisms.
e. Students know that extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient for its survival.
Structure and Function in Living Systems
5. The anatomy and physiology of plants and animals illustrate the complementary nature of structure and function. As a basis for understanding this concept:
a. Students know plants and animals have levels of organization for structure and function, including cells, tissues, organs, organ systems, and the whole organism.
b. Students know organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system.
Investigation and Experimentation
7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations.