LESSON 13: SALMON NUTRIENT
CYCLING
ESSENTIAL QUESTION:
What combination of factors both natural and manmade is
necessary for healthy river restoration and how does this
enhance the sustainability of natural and human communities?
GUIDING QUESTION:
Salmon nutrients find their way into terrestrial environments, how is it possible that trees
show evidence of having derived nutrition from Salmon?
OVERVIEW:
This lesson focuses on how marine-derived nutrients from salmon carcasses find their way
into terrestrial environments and how scientists can track these marine-derived nutrients
to analyze their importance to ecosystems today, as well as, reconstructing past ecosystem
processes. Terrestrial vertebrates such as mammals and birds, as well as, insects consume
salmon carcasses and then release those nutrients onto land, either by dragging the
carcasses or defecating onto the forest. These nutrients then enter the soil, where they are
taken up by plant roots. Once entering plant tissue, they are consumed by herbivores.
Salmon nutrients have been found in every living organism investigated and up to seven
miles from the stream of origin. Scientists use stable isotope N
15
to track marine-derived
nutrients, because this isotope is more common in marine environments than freshwater
ones. Analyzing sediment layers of lakes for this isotope, scientists can reconstruct ancient
salmon abundance and can make inferences to historic climate and ecological processes.
TIME:
One class period
MATERIALS:
Lesson 13- Salmon Nutrient Cycling.pptx
Lesson 13a- Salmon Nutrient Cycling.pdf
Food Web Lab.pdf
Food Web Quiz.pdf
Reflection Journal Pages (Printable Handout)
Vocabulary Notes (Printable Handout)
PROCEDURE:
1. Review Essential Question; introduce Guiding Question.
2. Students should take a few minutes to respond to the first reflection prompts.
Discuss their answers and any questions they’ve generated.
3. Hand out the Vocabulary Notes. With this lesson you may want to define the words
before presenting the PowerPoint Lesson
4. Present the PowerPoint Lesson
5. Food Web Lab Activity
6. Food Web Quiz
7. Hand out the second Reflection Journal Page. Give students time for a final reflection
the lesson.
ASSESSMENTS:
WASHINGTON STATE STANDARDS:
SCIENCE
1. EALR 4: 6-8 LS2A An ecosystem consists of all the populations living within a
specific area and the nonliving factors they interact with. One geographical area may
contain many ecosystems.
a. Explain that an ecosystem is a defined area that contains populations of
organisms and nonliving factors.
b. Give examples of ecosystems (e.g., Olympic National Forest, Puget Sound, one
square foot of lawn) and describe their boundaries and contents.
2. EALR 4: 6-8 LS2B Energy flows through an ecosystem from producers (plants) to
consumers to decomposers. These relationships can be shown for specific
populations in a food web.
a. Analyze the flow of energy in a local ecosystem, and draw a labeled food web
showing the relationships among all of the ecosystem’s plant and animal
populations.
READING
1. EALR 1: The student understands and uses different skills and strategies to read.
a. Component 1.2 Use vocabulary (word meaning) strategies to comprehend
text.
SOCIAL STUDIES
1. EALR 5: The student understands and applies reasoning skills to conduct research,
deliberate, form, and evaluate positions through the processes of reading, writing,
and communicating.
a. Component 5.2: Uses inquiry-based research.
WRITING
1. EALR 2: The student writes in a variety of forms for different audiences and
purposes.
a. Component 2.1: Adapts writing for a variety of audiences.
b. Component 2.2 Writes for different purposes.
ADDITIONAL RESOURCES AND ENRICHMENT:
http://newstandardnews.net/content/index.cfm/items/2854
http://chamisa.freeshell.org/food.htm
http://www.wildlifenews.alaska.gov/index.cfm?adfg=wildlife_news.view_article&articles_i
d=97
FOR STRUGGLING LEARNERS:
http://www.snh.org.uk/Salmonintheclassroom/salmon_foodchains.shtml
http://www.scienceisart.com/B_FoodChain/FoodChain.html
VOCABULARY TERMS:
Stable Isotope: An isotope which does not spontaneously undergo radioactive
decay
Carcass: The dead body of an animal,
Marine-derived Nutrients: Nutrients acquired by an anadromous fish and
deposited in a freshwater or terrestrial ecosystem when that fish dies.
Nitrogen-15 isotope: A stable, non-radioactive, rare isotope of Nitrogen containing
8 neutrons instead of 7. It is more common in marine environments that freshwater
or terrestrial habitats. Thus, its elevated presence outside of a marine environment
is an indication that nutrients are marine-derived
Terrestrial: Of or relating to the earth or its inhabitants
Vertebrate; an animal with a backbone, such as a fish, amphibian, reptile, bird, or
mammal
Elwha River Restoration
Salmon Nutrient Cycling
Reflection Journal 1
How do you think it’s possible that trees up to seven miles from salmon streams show
evidence of having derived nutrition from Salmon?
What questions do you have about nutrients from salmon?
Elwha River Restoration
Salmon Nutrient Cycling
Vocabulary Notes
Stable Isotope:
Carcass:
Marine-derived Nutrients (MDN)-
Nitrogen-15 Isotope-
Terrestrial:
Vertebrate:
Elwha River Restoration
Salmon Nutrient Cycling
Reflection Journal 2
How important are salmon to marine and terrestrial ecosystems?
What questions do you have about the importance of salmon to marine and terrestrial
ecosystems?
FOOD WEB LAB
In this lab, we will be imitating a small terrestrial riparian food chain in which sunflowers
represent the lowest tropic level (the producers), mice represent the primary consumers,
mink represent the secondary consumers, and cougars represent tertiary consumers. The
raccoon is an omnivore that can feed at multiple trophic levels.
You will draw a slip from a hat to determine which organism you are on the food chain.
You will then be assigned a certain quantity of energy points. If you get eaten you will give
up points to what ate you. If you eat, you will receive points from that prey item. If you
encounter something you can not eat, you will lose points from the energy required to fight
with or deal with that organism. At the beginning of each round, sunflowers will acquire 1
energy unit each from photosynthesis.
Once you know which organism you are, DO NOT tell anyone. Simply walk around until I
say FEED! If you are an animal, at that moment, approach someone near you and say “I am
a BLANK, can I eat you?” If they reveal that they are a prey item, take the appropriate
number of energy points from them. If they reveal themselves to be one of your predators,
you will give them the points because you were eaten. If you are sunflower, don’t say
anything, just let them approach you.
Animals
Total
Energy
Start
Total
Energy
Round 1
Total
Energy
Round 2
Total
Energy
Round 3
Total
Energy
Round 4
Cougar (1)
44 - 44
Raccoon (1)
30 - 30
Mink (3)
24 - 72
Mouse (5)
16 - 80
Sunflower
(10)
12 -120
+ Energy
gained by
photosynthesis
∑ Energy (16)
346
minus Energy
lost to heat
At the end of the round, write down on the back of your slip what happened and how
many energy points you gained or lost. We will run four rounds and then see how the
energy units end up. At the end of the lab, you will subtract 8 points (3 points for
sunflowers) as heat lost to the environment and we will see how much energy is left over.
Cougar
Raccoon
Mink
Mink
You can not be
eaten
You can be eaten
by a Cougar, but
not a snake.
You have 24 energy
points.
You have 24 energy
points.
You start with 44
energy points
You have 30
energy points
You can be eaten by
a cougar, but not a
raccoon.
You can be eaten by
a cougar, but not a
raccoon.
If you eat a
Raccoon you gain
10 energy points.
If you are eaten
by a Cougar you
lose 10 energy
points.
If you are eaten by a
Cougar you lose 10
energy points.
If you are eaten by a
Cougar you lose 10
energy points.
If you eat a mink
you gain 8 energy
points.
If you eat mice
you gain 4 energy
points.
If you eat mice, you
gain 4 energy
points.
If you eat mice, you
gain 4 energy
points.
If you eat mice,
you gain 4 energy
points.
If you eat a
sunflower you
gain 2 energy
points.
If you fight a
raccoon you lose 5
energy points in the
fight.
If you fight a
raccoon you lose 5
energy points in the
fight.
If you try to eat
sunflower, you
lose 8 energy
points.
If you fight a
mink, you lose 5
energy points.
If you try to eat a
sunflower, you lose
2 energy points.
If you try to eat a
sunflower, you lose
2 energy points.
Mouse
Mouse
Mouse
Mouse
Mouse
You have 16 energy
points
You have 16 energy
points
You have 16 energy
points
You have 16 energy
points
You have 16 energy
points
You can be eaten by
Cougars, mink, and
raccoons.
You can be eaten by
Cougars, mink, and
raccoons.
You can be eaten by
Cougars, mink, and
raccoons.
You can be eaten by
Cougars, mink, and
raccoons.
You can be eaten by
Cougars, mink, and
raccoons.
If you are eaten you
lose 4 energy
points.
If you are eaten you
lose 4 energy
points.
If you are eaten you
lose 4 energy
points.
If you are eaten you
lose 4 energy
points.
If you are eaten you
lose 4 energy
points.
If you eat a
sunflower you gain
2 energy points.
If you eat a
sunflower you gain
2 energy points.
If you eat a
sunflower you gain
2 energy points.
If you eat a
sunflower you gain
2 energy points.
If you eat a
sunflower you gain
2 energy points.
If you encounter
another mouse you
lose 1 point.
If you encounter
another mouse you
lose 1 point.
If you encounter
another mouse you
lose 1 point.
If you encounter
another mouse you
lose 1 point.
If you encounter
another mouse you
lose 1 point.
Sunflower
Sunflower
Sunflower
Sunflower
Sunflower
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You can be eaten by
mice and raccoons
You can be eaten by
mice and raccoons
You can be eaten by
mice and raccoons
You can be eaten by
mice and raccoons
You can be eaten by
mice and raccoons
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Sunflower
Sunflower
Sunflower
Sunflower
Sunflower
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You have 10 energy
points
You can only be
eaten by mice and
raccoons
You can only be
eaten by mice and
raccoons
You can only be
eaten by mice and
raccoons
You can only be
eaten by mice and
raccoons
You can only be
eaten by mice and
raccoons
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
If you are eaten you
lose 2 energy
points.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
Every round you
gain 1 energy point
from the sun
through
photosynthesis.
THOUGHT QUESTIONS
1) Which organisms had an overall increase in energy points?
2) Which organisms had the most decrease in total energy points?
3) Why did we have more sunflowers than mice and more mice than mink?
4) Do you think this was a realistic exercise in how a food chain operates? Why or why
not?
5) If you could adjust this game to make it more realistic, how would you change it?
6) Would you change the number of organisms in each category or add any more
categories?
7) Would you change the number of energy points each starts with or how many they
get for feeding? What else could help?
8) If you wanted to add decomposers to this game, what would you need to do?