U N I T 1 BUILDING KNOWLEDGE: The Salmon Life Cycle

Transcription

1 U N I T 1 BUILDING KNOWLEDGE: The Salmon Life Cycle

2 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, waste

3 Background 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 formation begins Organ formation begins Eyes become visible Oxygenated water Temperature from 5º to 9ºC Silt-free gravel bed Steady water flow Stream cover Yolk of egg Trout Sucker Squawfish Whitefish Kingfisher Gull Merganser Mink Otter Gravel movement Drastic change in water temperature Drastic change in water level Siltation Fine sediment Disease Pollution Alevin Embryo breaks through egg membrane Oxygen absorbed through gills Lives in gravel spaces Oxygenated water Temperature from 5º to 14ºC Silt-free gravel bed Steady water flow Stream cover Yolk sac Trout Sucker Squawfish Whitefish Kingfisher Gull Merganser Mink Otter Gravel movement Drastic change in water temperature Drastic change in water level Siltation Fine sediment Disease Pollution Fry Inflates swim bladder Catches food Exhibits darting reflex Avoids light Guards territory Imprints home scent Stream cover Oxygenated water Temperature from 5 to 14ºC Even water level and flow Larval and adult terrestrial and aquatic insects, (e.g. mayfly, caddisfly, true flies) Rotting fish carcasses Fish eggs Trout Sucker Squawfish Whitefish Kingfisher Gull Merganser Mink Otter Gravel movement Drastic change in water temperature Drastic change in water level Siltation Fine sediment Disease Pollution Blockage of migration route UNIT 1: Building Knowledge 3

4 Life cycle stage Needs Threats Habitat Food Predators Other Smolt Migrates to estuary Adapts to salt water Developes scales and silver colour develop Increases size Unpolluted water in river and estuary Estuary vegetation for shelter Zooplankton (copepods amphipods, euphausids) Insects, (e.g. beetles, ants, grasshoppers, caterpillars) Worms Sandfleas Shrimp Mackerel Grayling Trout Char Loon Heron Tern Kingfisher Hake Pollack Dogfish Older salmon Filling or dredging of estuary Pollution of estuary Diversion of river water Ocean Phase Salmon Migrates into ocean Increases size Stocks intermingle, then return to home river Ocean water Zooplankton, (e.g. amphipods, copepods, euphausids) Larval crustaceans, (e.g. crab shrimp) Small fish, (e.g. herring, squid, mackerel) Tuna Cod Pollock Hake Lamprey Gull Heron Cormorant Seals Whales People "Lost" nets Ocean pollution Ocean temperature change Fishing Spawner Eggs, milt develop Secondary sexual characteristics develop (colour, shape, teeth) Scales absorbed Eating stops Organs degenerate Migration route free from obstructions Oxygenated water Cool clean water Silt-free gravel None Eagles Bears Otters Minks People Very high or low water levels Warm river temperatures Obstructions (dams, slides, log jams, etc.) Diseases Pollution 4 SALMONIDS IN THE CLASSROOM: INTERMEDIATE

5 Looking Ahead at Salmon Studies [discussion] Suggested Activities Choose activities from these suggestions that are appropriate for your class. Discussion < Have students form pairs and explain that this activity will focus on their knowledge about salmon. < Have students review the first statement on Handout 1.1: Looking Ahead at Salmon Studies and answer the questions provided under each heading. Adapted from Faye Brownlie and Susan Close, Beyond Chalk and Talk, Anticipation Guide, pages Materials: 4 One copy of Handout 1.1: Looking Ahead at Salmon Studies for each student 4 Writing supplies Time required: Approximately 30 minutes Level of conceptual difficulty: Simple Suggestions for assessment: Monitor the class discussion to assess the students level of understanding of the language and concepts used in salmon studies. < Give students a few minutes to discuss their answers and reasons with their partner and to confirm or change their answers. < Ask the class to share some of their answers and post them for future reference during salmon studies. Summation Explain that the questions reflect some of the key ideas students will investigate in the salmon studies which follow. As they do the salmon studies activities, ask them to look for information that will help confirm or change what they wrote on the handout. UNIT 1: Building Knowledge 5

6 Introduction to Life Cycles Discussion < 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 generation. < 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: INTERMEDIATE

7 Salmon Life Cycle Chart [Building-on-what-you-know] Materials: 4 One copy of Handout 1.2: Salmon Life Cycle Needs and Threats for each student Introduction < 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 your students may have as they are introduced to the salmon s life cycle. < Use one of the references listed in the Marine and Aquatic 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 they will add details to the chart and refer back to it as they study other stages in the salmon s life cycle. 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 7

8 B 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

9 HANDOUT 1.1 Looking Ahead at Salmon Studies Name The salmon life cycle? What Do You Know About What Would You Like To Know About Salmon needs and threats? The water cycle? Healthy salmon habitat? Salmon anatomy? Incubation? Water quality? Responsible fishing? Stewardship? UNIT 1: Building Knowledge 9

10 Egg HANDOUT 1.2 Salmon Life Cycle Needs and Threats Life cycle stage Needs Threats Habitat Food Predators Other Alevin Fry Smolt Adult salmon Spawner 10 SALMONIDS IN THE CLASSROOM: INTERMEDIATE

11 HANDOUT 1.2 Salmon Life Cycle Needs and Threats UNIT 1: Building Knowledge 11

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