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Anadromous Adventures

Lesson at a glance:

Students will follow the life cycle of a salmon and become aware of some of the threats it faces as it migrates from spawning grounds to the ocean and back again.

Relevant National Curriculum Standards and Benchmarks:

Science standard (4): Knows about the diversity and unity that characterize life

Benchmark: Primary (Grades K-2): Knows that plants and animals have features that help them live in different environments.
Benchmark: Upper Elementary (Grades 3-5): Knows that plants and animals progress through life cycles of birth, growth and development, reproduction, and death; the details of these life cycles are different for different organisms.
Benchmark: Middle School/Jr. High (Grades 6-8): Knows that animals and plants have a great variety of body plans and internal structures that serve specific functions for survival.

Science standard (7): Understands how species depend on one another and on the environment for survival

Benchmark: Upper Elementary (Grades 3-5): Knows that the behavior of individual organisms is influenced by internal cues (e.g., hunger) and external cues (e.g., changes in the environment), and that humans and other organisms have senses that help them to detect these cues.
Benchmark: Upper Elementary (Grades 3-5): Knows that an organism's patterns of behavior are related to the nature of that organism's environment.
Benchmark: Upper Elementary (Grades 3-5): Knows that changes in the environment can have different effects on different organisms.
Benchmark: Upper Elementary (Grades 3-5): Knows that all organisms (including humans) cause changes in their environments, and these changes can be beneficial or detrimental.
Benchmark: Middle School/Jr. High (Grades 6-8): Knows how an organism's ability to regulate its internal environment enables the organism to obtain and use resources, grow, reproduce, and maintain stable internal conditions while living in a constantly changing external environment.
Benchmark: Middle School/Jr. High (Grades 6-8): Knows factors that affect the number and types of organisms and ecosystem can support.
Benchmark: High School (Grades 9-12): Knows ways in which humans can modify ecosystems and cause irreversible effects.

Science standard (8): Understands the cycling of matter and flow of energy through the living environment

Benchmark: Primary (Grades K-2): Knows that plants and animals need certain resources for energy and growth (e.g., food, water, light, air).
Benchmark: Upper Elementary (Grades 3-5): Knows that the transfer of energy (e.g., through the consumption of food) is essential to all living organisms.

Geography standard (8): Understands the characteristics of ecosystems on Earth's surface

Benchmark: Upper Elementary (Grades 3-5): Knows ways in which humans can change ecosystems.

Geography standard (14): Understands how human actions modify the physical environment.

Benchmark: Upper Elementary (Grades 3-5): Knows ways people alter the physical environment.
Benchmark: Upper Elementary (Grades 3-5): Knows ways the environment is stressed by human activities.
Benchmark: Middle School/Jr. High (Grades 6-8): Understands the environmental consequences of people changing the physical environment.
Benchmark: Middle School/Jr. High (Grades 6-8): Understands the ways in which human changes in the physical environment in one place can cause changes in other places.
Benchmark: High School (Grades 9-12): Understands the role of humans in decreasing the diversity of flora and fauna in a region.

These national standards and benchmarks are summarized at http://www.mcrel.org/standards-benchmarks/

Materials:

• One sheet of 2’ x 3’ poster board per game
• One brad per game
• Glue
• Scissors
• A hole punch
• One copy per game of the spinner, game board diagram and clues
• 20 energy chips per player (poker chips work well, or you can keep score on a sheet of paper)
• A tokens for each student or teams (can be anything)

Background:

A salmon's life cycle
The salmon life cycle begins as an egg buried in loose gravel in a cool stream with lots of oxygen. When the salmon first hatch they are called alevins. They wait in the gravel until they finish the last of their yolk then hurry to the surface for a quick gulp of air to fill their swim bladders.

As the young fry near the estuary they become smolts. Their scales grow, they become more silvery to help blend into the ocean environment. The smolts feed like mad in the estuary, trying to become as big as they can before braving the treacherous waters of the Pacific ocean.

Salmon at sea might migrate thousands of miles or they may stay right off the coast. They may spend anywhere between 2 and 8 years feeding in the ocean before returning to their native rivers and streams to spawn. Their homing abilities are legendary and not entirely understood.

On the way back salmon make another stop in coastal estuaries. Like last time, their bodies go through chemical changes so they can survive in the freshwater of their home streams. This time they also stop eating and adopt their flashier, spawning colors. Males may get hooked beaks and humped backs. The journey home is a daunting one, only the strongest will survive to reproduce.

Those salmon who make it will go through the final task of their lives. The females will build gravel nests with their tails called redds. and the males will fight for the opportunity to fertilize the females eggs. Although some steelhead and cutthroat will live to spawn again, most anadromous salmon will die after spawning. Their bodies feed the stream environment.

Perils of the journey
The journey to and from the spawning grounds is dangerous indeed.

Not even the egg is safe. Some predators prefer eggs because they are high energy sources of food. Careless hikers, unleashed dogs and other disturbances can destroy redds and either crush eggs or loose them to drift downstream. too much erosion can cause silt to smother the redds and suffocate the eggs. Streamside vegetation and responsible forestry can help reduce this hazard.

When the fry emerge from the gravel they are very vulnerable to predators. They are small and need to learn very quickly how to hide. Predators are natural but around dams predators gather to await salmon fry that are spilled over the top or rocketed through bypasses. Young salmon must also be wary of dam turbines, and irrigation water diversions. When the plant life along the streamside is removed the temperatures in the stream increase, the flow is reduced and their are fewer insects to eat. Pollution from cities and farms also takes its toll.

At sea, adult salmon must deal with not only the larger oceanic predators like sharks and killer whales but also with commercial fisheries.

And the trip back upstream can be even more dangerous. Adults have to face natural predators like bear and eagles plus both commercial and recreational fishers. Dams bar the path of migrating salmon. Those who make it up the fish ladders may become confused or even sick in the warmer slack waters above the dam. Pollution, erosion and water diversions play key roles in preventing adults from successfully spawning by destroying good salmon spawning habitat.

Activity:

1. Before class, copy the spinner, arrow, game board and clues for each game you will be making.
2. Cut out the spinner and arrow. Glue them onto the poster board or laminate them. Punch a hole in the center of the spinner and the arrow and insert a brad. Adjust the brad so that the arrow spins.
3. Glue the game board onto a piece of poster board.
4. Cut out the clues and glue them near the corresponding number on the game board.
5. Choose tokens for use in the game and give one to each student. Students could draw or create their own salmon game tokens with their name on them.
6. Divide your students into groups of 4-6.
7. Explain the following directions to the class:
   1. Put your token on B and read the introduction. Each player starts with 20 energy chips.
   2. All players move to the first space and read the clue.
   3. After you have read the clue, have each player spin the spinner and follow the directions.
   4. Now move to the next space.
   5. Continue taking turns until you reach you spawning grounds again..

Summary:

With your students (or kids or friends), discuss the following questions:

1. What natural hazards did you, as a salmon, face?
2. What human-made hazards did you face?
3. What are a salmon's basic needs? How are they threatened by human activity?

Extensions:

• Remove all the human-made hazards and play again. Now how do your salmon score?
• Research other fish and animal life cycles. Compare them to a salmon's.
• Brainstorm about what your class can do to make the salmon's migration easier.

Game Clues:

Introduction
Coho salmon eggs are laid in the gravel at the bottom of a stream during the late fall.  The salmon embryos develop in the eggs over the winter.  It is now early spring and the eggs have hatched.  You are a young salmon called an alevin.  It is time to begin your journey to the ocean.

1. A yolk sac attached to your belly is your food for the first couple of months.  You hide under rocks to keep from getting eaten.  Spin.
   1. You are healthy. Lose 0 chips
   2. You are in an area where the water flows too slowly and you don't get enough oxygen. Lose 1 chip.
   3. A hikers steps through your redd. Lose 2 chips.
2. Later in the spring, you swim out from the rocks. You are now called a fry. You begin to eat tiny plants and insects. A shaded stream with places to hide would be the best spot for you. Spin.
   1. Farm fertilizers run into the stream, you are weakened by pollution. Lose 2 chips.
   2. Your stream has no shade because cattle have eaten all the plants around it. The warmer water has less oxygen and fewer insects to eat. Lose 2 chips.
   3. You live in a healthy stream and have plenty to eat. Lose 0 chips.
3. After a year in your stream, you head towards the sea. Your body goes through changes to prepare for the switch from fresh to salt water. These changes are called "smolting" and you are now called a smolt. You face many dangers. Spin.
   1. You saved energy by catching a quick current downstream. Lose 0 chips.
   2. You approach a dam where the water moves much slower. You must use more energy to swim. Lose 2 chips.
   3. You were caught by a fisherman and almost mistaken for a trout, but he throws you back. Lose 3 chips.
4. Think of some problems you could have while swimming downstream. Dams create pools of still or slow moving water. Water pollution could weaken you or reduce your food supply. Irrigation and other water diversions take water from you stream and make the trip more difficult. Spin.
   1. You must swim to escape a larger fish waiting in a still pool near a dam. Lose 2 chips.
   2. You are slowed by still water near the dam. Lose 1 chip.
   3. You make it through a turbine bypass okay. Many fish are sucked into the turbine and die. Lose 0 chips.
5. You finally come to the estuary, a place where fresh and salt water mix. Your scales have become larger and silvery. Your belly becomes lighter so that fish in the ocean environment won't be able to see you very well from below. You'll stay here a little while until your body gets used to the salt water. Spin.
   1. You have been swept downstream by a flood and reach the estuary before you are ready. Lose 2 chips.
   2. You reach the estuary safely. Lose 0 chips.
   3. You are grabbed by a hungry heron but you get away. Lose 2 chips.
6. You'll eat a lot at the estuary. If you can get big before heading out to sea, you'll have a better chance to survive. You may be migrating hundreds or even thousands of miles across the ocean. Spin.
   1. You get tangled in a fisherman's net an lose energy escaping. Lose 3 chips.
   2. Your estuary is polluted; it's harder to find food. Lose 2 chips.
   3. You are a big salmon and ready to head out to sea. Lose 0 chips.
7. You'll live in the ocean for up to seven or eight years. A signal known only to salmon will tell you it's time to go home. You are guided by electromagnetic signals, the moon and stars, and the smell of you home stream. Spin.
   1. You are weakened by an oil spill. Lose 2 chips.
   2. You are sick and lose your ability to navigate. Lose 3 chips.
   3. You are headed in the right direction. Lose 0 chips.
8. When you enter fresh water again, you stop feeding, even if your river journey is 1,000 miles. You will change your color, your stomach will shrink, and you will get sick more easily. Your stored fat and muscle must last until you breed. Spin.
   1. A dam's fish ladder slows you down. The water on the other side is warm and disease spreads easily here. You become sick. Lose 2 chips.
   2. A landslide partially blocks your way. Lose 1 chip.
   3. You make it to your home stream safely. Lose 0 chips.
9. You have reached your home stream. It is now time to breed. If you are a female, you will be making a nest called a redd to lay your eggs in. If you are a male, you will be fighting to fertilize those eggs. Count your chips and move ahead to E and check the chart below to see how successful you will be at breeding.

Female

Male

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