BUILDING KNOWLEDGE: The Salmon Life Cycle - UNIT
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U N I T 1 BUILDING KNOWLEDGE: The Salmon Life Cycle
Building
Knowledge:
The Salmon
Life Cycle
Overview
This unit gives students an opportunity to:
• examine and discuss their pre-existing ideas about
salmon;
• discuss what a life cycle is;
• review the stages of a salmon’s life cycle.
Key Concept
The stages in a salmon’s life form a cycle, but each stage has
specific needs and is vulnerable to disruption and mortality.
Vocabulary
Salmon, life cycle, habitat, wasteBackground Information
In addition to the information in "Handout 10.1: Salmon Survival”
the following information may be useful:
Salmon life cycle needs and threats
Life cycle stage Needs Threats
Habitat Food Predators Other
Egg
• Head and body for- • Oxygenated water • Yolk of egg • Trout • Gravel movement
mation begins • Temperature from 5º • Sucker • Drastic change in
• Organ formation to 9ºC • Squawfish water temperature
begins • Silt-free gravel bed • Whitefish • Drastic change in
• Eyes become visible • Steady water flow • Kingfisher water level
• Stream cover • Gull • Siltation
• Merganser • Fine sediment
• Mink • Disease
• Otter • Pollution
Alevin
• Embryo breaks • Oxygenated water • Yolk sac • Trout • Gravel movement
through egg mem- • Temperature from 5º • Sucker • Drastic change in
brane to 14ºC • Squawfish water temperature
• Oxygen absorbed • Silt-free gravel bed • Whitefish • Drastic change in
through gills • Steady water flow • Kingfisher water level
• Lives in gravel • Stream cover • Gull • Siltation
spaces • Merganser • Fine sediment
• Mink • Disease
• Otter • Pollution
Fry
• Inflates swim blad- • Stream cover • Larval and adult • Trout • Gravel movement
der • Oxygenated water terrestrial and • Sucker • Drastic change in
• Catches food • Temperature from 5 aquatic insects, • Squawfish water temperature
• Exhibits darting to 14ºC (e.g. mayfly, cad- • Whitefish • Drastic change in
reflex • Even water level disfly, true flies) • Kingfisher water level
• Avoids light and flow • Rotting fish car- • Gull • Siltation
• Guards territory casses • Merganser • Fine sediment
• Imprints home • Fish eggs • Mink • Disease
scent • Otter • Pollution
• Blockage of migra-
tion route
UNIT 1: Building Knowledge 3Life cycle stage Needs Threats
Habitat Food Predators Other
Smolt
• Migrates to estuary • Unpolluted water in • Zooplankton (cope- • Mackerel • Filling or dredging
• Adapts to salt water river and estuary pods amphipods, • Grayling of estuary
• Developes scales • Estuary vegetation euphausids) • Trout • Pollution of estuary
and silver colour for shelter • Insects, (e.g. • Char • Diversion of river
develop beetles, ants, grass- • Loon water
• Increases size hoppers, caterpil- • Heron
lars) • Tern
• Worms • Kingfisher
• Sandfleas • Hake
• Shrimp • Pollack
• Dogfish
• Older salmon
Ocean Phase Salmon
• Migrates into ocean
• Increases size • Ocean water • Zooplankton, (e.g. • Tuna • "Lost" nets
• Stocks intermingle, amphipods, cope- • Cod • Ocean pollution
then return to pods, euphausids) • Pollock • Ocean temperature
home river • Larval crustaceans, • Hake change
(e.g. crab shrimp) • Lamprey • Fishing
• Small fish, (e.g. • Gull
herring, squid, • Heron
mackerel) • Cormorant
• Seals
• Whales
• People
Spawner
• Eggs, milt develop • Migration route free • None • Eagles • Very high or low
• Secondary sexual from obstructions • Bears water levels
characteristics • Oxygenated water • Otters • Warm river tempera-
develop (colour, • Cool clean water • Minks tures
shape, teeth) • Silt-free gravel • People • Obstructions (dams,
• Scales absorbed slides, log jams,
• Eating stops etc.)
• Organs degenerate • Diseases
• Pollution
4 SALMONIDS IN THE CLASSROOM: INTERMEDIATESuggested Activities
Choose activities from these suggestions that are appropriate
Looking for your class.
Ahead at Discussion
Salmon
< Have students form pairs and explain that this activity
will focus on their knowledge about salmon.
Studies < Have students review the first statement on “Handout
1.1: Looking Ahead at Salmon Studies” and answer the
questions provided under each heading.
[discussion]
Adapted from Faye Brownlie and < Give students a few minutes to discuss their answers and
Susan Close, Beyond Chalk and Talk, reasons with their partner and to confirm or change their
“Anticipation Guide”, pages 54 - 67 answers.
Materials:
4 One copy of “Handout 1.1: Looking < Ask the class to share some of their answers and post
Ahead at Salmon Studies” for each them for future reference during salmon studies.
student
4 Writing supplies
Time required:
Approximately 30 minutes Summation
Explain that the questions reflect some of the key ideas
Level of conceptual difficulty: students will investigate in the salmon studies which follow.
Simple
As they do the salmon studies activities, ask them to look for
Suggestions for assessment: information that will help confirm or change what they wrote
Monitor the class discussion to assess the on the handout.
students’ level of understanding of the
language and concepts used in salmon
studies.
UNIT 1: Building Knowledge 5Discussion
< Ask students to explain what a life cycle is and to give
some examples.
A life cycle is the series of stages an organism goes through
from birth to death, including the reproduction of a new
Introduction to generation.
Life Cycles < Have the class state the stages in the life cycle of a
salmon.
Egg, alevin, fry, smolt, adult, spawner.
< Explain that this unit gives students a chance to review
the stages and conclude their salmon studies.
Materials:
None
Time required:
10 minutes
6 SALMONIDS IN THE CLASSROOM: INTERMEDIATEIntroduction
< Read the background information in each unit to
familiarize yourself with the life cycle of the Pacific
salmon. This should prepare you to answer any questions
Salmon Life your students may have as they are introduced to the
salmon’s life cycle.
Cycle Chart < Use one of the references listed in the Marine and Aquatic
[Building-on-what-you-know] Educators Resource Guide to show students a film of
the salmon’s life cycle, or read them a book that briefly
summarizes the stages in the life cycle of a salmon.
< Give each student a copy of “Handout 1.2: Salmon
Life Cycle Needs and Threats”. Have the students fill in
information based on what they have heard or already
know about salmon needs and habitat. Tell students that
Materials:
they will add details to the chart and refer back to it as
4 One copy of “Handout 1.2: Salmon
they study other stages in the salmon’s life cycle.
Life Cycle Needs and Threats” for each
student
Time required:
Approximately one period
Level of conceptual difficulty:
Moderate
Suggestions for assessment:
Review the lists the groups create and
monitor the class discussion to ensure
that the students can identify key factors
affecting a salmon’s life during the egg
stage.
Illustration: Karen Uldall-Ekamn
UNIT 1: Building Knowledge 7B U I L D I N G K N O W L E D G E : T H E S A L M O N L I F E C Y C L E Wrap-up Suggestions for Assessment < Have students place “Handout 1.1: Looking Ahead at Salmon Studies” in a salmon studies notebook or portfolio where they can collect other materials from their salmon studies and review the contents later to see if their ideas have changed. Use the student notes or portfolio in a conference to assess student attitudes and affective changes during this unit. < Repeat the activity after students complete their salmon studies and have them compare their answers. Have them write a reflective journal entry in which they examine how and why their opinions changed. 8 SALMONIDS IN THE CLASSROOM: INTERMEDIATE
HANDOUT 1.1
Looking Ahead at
Salmon Studies
Name ______________________________________________________________________________
What Do You Know About… What Would You Like To Know About…
The salmon life cycle?
Salmon needs and threats?
The water cycle?
Healthy salmon habitat?
Salmon anatomy?
Incubation?
Water quality?
Responsible fishing?
Stewardship?
UNIT 1: Building Knowledge 9HANDOUT 1.2
Salmon Life Cycle
Needs and Threats
Life cycle stage Needs Threats
Habitat Food Predators Other
Egg
Alevin
Fry
Smolt
Adult salmon
Spawner
10 SALMONIDS IN THE CLASSROOM: INTERMEDIATEHANDOUT 1.2
Salmon Life Cycle
Needs and Threats
UNIT 1: Building Knowledge 1112 SALMONIDS IN THE CLASSROOM: INTERMEDIATE
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