Junior High School Lesson Plan
by Diane Higgins, M.A.
Lesson One: Life Cycle of Salmon and Steelhead
Students read a life cycle chart and gather information from the Internet to learn about salmon life cycles. The class creates a chart showing habitat requirements at each life stage.
Students will be able to:
- list, in order, each stage of the salmon and steelhead life cycle
- describe habitats fish use at each life stage
- explain other factors that influence survival of salmon
- Salmon and Steelhead Life Cycle (print from this site)
- Internet connection and computer(s)
- Large piece of paper for making chart
- Felt pens
- Wall map of Pacific Northwest and/or California
Salmon and steelhead have always been an integral part of Pacific Northwest ecosystems and human social structures. In rivers and streams ranging from Alaska to California, these amazing fish migrate from their freshwater rearing grounds to the ocean, where they grow large on a rich supply of food. When they are mature, after 2 to 4 years roaming the open seas, they return to the stream of their birth to spawn a new generation and complete their own life cycle. Except for steelhead, all Pacific salmon species die soon after spawning, and the nutrients they gathered in the ocean are released into the stream as their bodies decay. In this way, salmon bring a valuable gift back to the stream - nourishment for an ecosystem where nutrients are constantly being washed away by flowing water. Salmon and steelhead are also a nourishing gift to humans.
When European settlers arrived in the Pacific Northwest, they thought the supply of salmon was boundless. However, as our population has grown, so has our demand for water. When systems were designed for delivering water to humans, the fish were not the highest priority. Dams constructed to store water and generate electricity became impassible barriers to migrating fish. In California's Central Valley, the available salmon habitat throughout the Sacramento and San Joaquin river systems has been reduced from 6,000 miles to only 300 miles. The impact on fish populations was dramatic.
Removing water from rivers for human use means there is less water available for the fish. As flows diminish and river levels drop, water temperatures tend to rise. Salmon and steelhead must have cold water to survive. The methods used for extracting the water can also harm fish. Diversion dams span the river and form barriers to migrating fish. Fish ladders and/or side channels for fish passage are often built, but they don't always work. Fry migrating downstream often swim into, or are drawn into diversions that take water directly from the river. Placing screens over diversions can eliminate this problem. Large dams that block much of a river's natural flow can profoundly alter fish habitat.
The Sacramento River is home to the endangered winter run chinook salmon. There are four separate runs of chinook salmon in the Sacramento, which means fish may be hatching, rearing or migrating up or down river at any time during the year. Since the winter run is listed as endangered, most of the water management strategies implemented are geared toward the survival of these fish.
Society has become concerned about the fate of salmon in the Sacramento River and other streams. With public support, laws, funding and multi-agency commitments addressing the issue of salmon survival, time will tell if present efforts can secure a long term future for these magnificent creatures.
- Starting from the NatureWater - Water and the Environment Resources page, review and printout the five Problems/Solutions pages, and visit the other web sites listed.
- Print the page titled Salmon & Steelhead Life Cycle, linked at the Resources page. Keep it as your master copy.
- Make an overhead transparency or make copies for students.
- Construct a chart with five columns, headed as shown below.
- Post for the students review all the on-line addresses for the web sites listed on the Resources page. The students can simply link from that page, also.
||WHERE ARE THEY?
For this lesson, you will complete only the first three columns of the chart. Problems and solutions are the topic of the next lesson. The information is summarized below.
||WHERE ARE THEY?
In a river or stream bed, buried 1-2 feet deep in a nest of gravel, called a redd.
- Clean gravel that water can flow through
- Sufficient flows
- Cold water temperatures
- Plenty of Dissolved Oxygen
- No food is required. Nutrients supplied by egg yolk.
Alevin (Sac fry)
Still buried in the gravel. Now they can move around, but they stay buried for several more weeks. When their yolk sacs are empty, they must swim out of the gravel to find food.
- Clean gravel that the fish can to get through when they swim up. Silted gravel can trap them.
- Sufficient flows
- Cold water temperatures
- Plenty of Dissolved Oxygen
- No food is required. Nutrients supplied by yolk sac on tiny fish's stomach.
In the margins of the river, or in places where the current is not too swift. As they grow bigger and stronger, they take up positions in swifter water.
- Protection from predators: under cut stream banks, tree roots, submerged logs, deep pools, rocks and gravel, and white water areas all provide cover.
- Food - mostly insects and other small stream dwelling animals
- Cold water and sufficient dissolved oxygen
At some point just before, or in conjunction with smolting, the fish begin their down stream journey. They may swim hundreds of miles, past many obstacles and dangers before reaching the estuary.
Most salmon remain for some time in the estuary, getting adjusted to the salt water and growing larger on new food sources.
Smolts need everything fry need.
They also need straightforward, unobstructed downstream access to the ocean.
Adult fish roam the Pacific Ocean for 2-4 years. They may not have to travel far because the ocean just off the California and Oregon coastline is rich with food.
When the fish become mature, they return to the river of their birth to spawn.
Adults in the ocean climb towards the top of the food chain as they grow larger. They need protection from over harvest at sea.
The warm ocean water of El Nino years hurt the salmon by reducing available food.
When fish return to the river, they need sufficient river flows and free access to their spawning grounds. Water must be cold and oxygen rich.
Most salmon stop eating once they enter fresh water.
||Moving upstream and at the spawning beds, near the place of their own birth.
- Sufficient water flows
- Unobstructed access upstream
- Cold, oxygen rich water
- Protection from poaching
- Enough clean gravel for every fish to spawn
Big fish, like chinook salmon choose larger gravel, while smaller fish, like steelhead, use smaller gravel. This helps reduce competition for spawning beds.
Questions for Discussion:
Ask students what they know about salmon and steelhead. Some students may have gone fishing for salmon or trout. Generate a class discussion about the fish to find out what they already know. Here are some questions to prompt their existing knowledge:
- Has anyone seen a salmon or steelhead trout?
- Where do these fish live? Do they use more than one habitat during their lives?
- Are these fish important to people? Why?
- Does anyone know the status of salmon and steelhead populations in California?
- What is an endangered species? What is a threatened species?
- Allow students time to conduct on-line research about the life cycle and habitat requirements of salmon and steelhead. Ask them to take notes as they use the Internet.
- Distribute the Salmon and Steelhead Life Cycle page or place the transparency on an overhead projector. Read it together and discuss the life cycle.
- On the chart, begin with the egg stage. Complete the first three columns with the students.
- How many types of habitats do salmon and steelhead inhabit during their lives?
- What are the fishes' consistent requirements while they are in fresh water?
- What do you think is happening to salmon and steelhead in our rivers today? Are fish populations healthy?
Lesson 2: Share the Water
Students will use materials provided at this site and gather information from other sites to make posters of river conditions with and without water sharing.
science, math, reading, geography
- Access to the Internet, an up-to-date browser, and a printer
- Printed master copy of the five Problems and Solutions pages,
linked from the Water NatureWater
- Water and the Environment Resources page
- Large sheets of butcher paper or poster boards, two for each group
- Colored felt pens
- Scissors and paste
- Popsicle sticks to represent dams
- About one square foot of screen, and shears for cutting it up into smaller sections
- Sand and pebbles to represent silt and spawning gravel
Review the general background above, and the results of the first lesson.
- Copy a set of the Problems and Solutions pages for each team.
Questions for discussion:
- How can we show the big picture for both water use and salmon migration?
- Does a big picture view help us to see how the many different factors can be managed?
- Does a big picture view benefit from having many people help to create it?
The first poster board will show a river with several problems for fish, such as warm water, dams, silt, no spawning gravel, unscreened diversions and dewatered streams. The second poster will show the same river with solutions in place - screens over diversions, dam raised part of the year, cooler temperatures, new spawning gravel, etc.
- Divide students into teams of five members. Each member will investigate a different problem and its solution.
- Allow time for students to read their assigned pages, and to visit sites on the Internet that demonstrate the problems and solutions. They can save photographs and illustrations they find on the web.
- Discuss, as a class, what they learned. Encourage students to describe the projects or techniques they learned about in detail.
- Give students materials for making posters. Tell them they may construct the posters as landscape models, lain flat, or as wall posters.
Each problem should have a brief description next to it. Students can paste written descriptions on the poster next to a feature. Flat models can display descriptions on little cardboard tents. Photographs should be captioned, with the source, web site location, and a description of what is shown.
Be sure to include:
- several dams - a big one like Shasta Dam, and a smaller, irrigation dam.
- impounded water behind the dams
- several irrigation diversion and canals
- indication of water temperature - warm water could grade from greenish blue & yellow to red; cold water could be a plain blue
- indication of water flow - shown with directional arrows, longer for faster flow, short for slow flow
- try to include some photographs from the web sites visited. Photos should show problems that exist for fish and solutions to the problems.
Display the posters. You may have to lay them flat on a table or the floor, especially if they are heavy with spawning gravel. Allow students to visit each others posters and discuss each feature.