Salmon Species Fishing Salmon Lesson Plans Salmon and Canadians All About Salmon |
Human Impact on SalmonPurpose: This lesson encourages students to discover the ways in which humans affect salmon, both positively and negatively. Curriculum Match: British Columbia, Science, Grade 4-7 Grade 4: It is expected that students will:
Grade 5: It is expected that students will:
Grade 7: It is expected that students will:
Materials: calculators (optional) Resources:Salmon Facts (see menu) Student handout:
Salmon Countdown (bottom of page) Preparation: Please review the procedures and resources used in this activity. Procedure: (If you have not conducted the Salmon Life Cycle lesson) Begin with a class discussion of what students already know about salmon. Encourage students to volunteer any experiences they have had with salmon (for example, seeing salmon swimming in a river, a visit to a hatchery, a family fishing trip). Use a KWL chart (Know, Wonder, Learn) to record students' responses. Use prompts as necessary to encourage students to think about the different aspects of the topic, such as: - the different species of salmon Record what students know to be facts in the Know column. Record questions in the Wonder column. Save this chart and add to it throughout the unit as students learn about salmon. Continue the discussion by focussing on the ways in which humans
and salmon interact. Record any new items to the KWL chart. For
example: Distribute the handout, Salmon Countdown (bottom of page), and allow a few minutes for students to complete the worksheet individually or in pairs. If you have not completed the Salmon Life Cycle lesson, you may need to refer students to the Salmon Facts resources (see menu) for information on each stage of the life cycle. When the activity is finished, debrief as a class: Ask: If you removed all of the dangers caused by humans, would the numbers change? If so, how? What effect might this have on the salmon? On species that depend on the salmon? Continue the discussion by asking students to suggest other threats to salmon that were not presented in the handout. Point out that disease and climate can also damage salmon populations. Next, ask students to brainstorm what humans can do to help salmon populations. Record their responses. If not included in students' suggestions, introduce the following initiatives: - hatcheries Divide the class into groups. Have each group use the suggested resources to research one of the salmon enhancement initiatives. Set the parameters of the final product (e.g., oral report, written, graphic, multimedia), and ensure students are clear about the task. Students' reports could include any or all of the following information: - examples of the initiative and how it worked When students have completed their projects, provide an opportunity for them to share their findings with the rest of the class. Allow time for questions. Debrief by adding any new information to the class KWL chart. Assessment: Use an observation sheet to assess students as they work in their groups. Look for evidence that they: - work co-operatively
- clarity of information Adaptations: The reading level of the resources used in this lesson may be too advanced for some grade 4 or 5 students. Use contextual support and/or reading buddies as necessary to facilitate student comprehension of the materials. For younger students or if resources are limited, the research and report activity can be altered, or replaced with a guided reading strategy of the Salmon Facts resources.
Extensions: For an interactive illustration of the effects of humans on salmon populations, have students play the Salmon Challenge game. Using the resources in Salmon Facts (see menu) focus on the controversial issue of salmon farms. Have students research and prepare a debate on the effects of salmon farms, such as "Be it resolved that salmon farming is beneficial to the survival of all salmon species". Ask the students to conduct interviews with their family or friends who have lived in the area for a long time. Interviews should focus on a comparison between the state of salmon populations now and in the past. As students present their interview results, encourage them to focus on why salmon populations have changed. What human activities have affected the salmon populations? What can humans do to reverse any negative effects? Have your class make presentations to a buddy class; or, have the class teach one-on-one or two-on-two with younger buddies. Suggest appropriate preparations, work pages and resources that they can use. Consider appropriate and timely field trips. *** The following may be copied onto separate pages to hand out. SALMON COUNTDOWN Pacific salmon have to face many dangers on their journey from an egg to adulthood. To investigate how many salmon will make it through their life cycle to spawn, follow the journey of these sibling salmon. This example looks at how many salmon will survive from one redd, or nest area. Many females will lay eggs in several nests. A female pacific salmon has returned to her home stream to spawn. She lays 5500 eggs in several small nests. Male salmon come along ready to fertilize the eggs, but one-tenth of the eggs (550) do not get fertilized. This leaves ________ fertilized eggs in the nests that have now been properly covered with gravel by the female. As the eggs are developing over the winter, a new road is constructed further up the stream. Lots of loose soil is left behind. A large rainstorm washes gravel, mud, and silt into the river. Nests upstream have been totally smothered. At this point in the stream, 800 eggs from this group are smothered and killed. The remaining eggs hatch into alevins that stay hidden in the gravel for another month. There are now ________ alevins. This stream runs through a farmer's land. He has been very busy making sure that the fences are repaired, but one of the fences has fallen down. The farmer's dairy cows have waded onto the gravel bar in the stream to drink the water. 1020 alevins are killed under the cows' hooves. The number of remaining alevins is ________. A brother and a sister are helping their father paint the house. When they are finished, they pour the unused paint into a storm drain next to their driveway. The drain empties directly into the stream and kills 530 alevins. There are now ________ alevins. The remaining alevins become fry and swim up out of the gravel. After two weeks the small fry begin their journey downstream to the ocean. People who live close to the streams have been using lots of chemicals on their lawns and gardens this year. Each time it rains, more chemical is washed into the river, which kills 245 salmon. Now there are ________ salmon to travel to the ocean. These salmon are called smolts and are silvery in colour. The salmon smolts finally reach the ocean. As juveniles, they try to avoid predators, but 1430 of them are eaten by seagulls, mackerel, and other fish. This leaves ________ salmon. As adults in the open ocean, killer whales feed on the group and 500 more are lost. There are now ________ salmon. People like to eat salmon! Commercial fishing boats in the ocean using different nets catch 375 of the sibling salmon. This leaves ________ of the original salmon to begin the journey home. As the salmon swim upstream toward the spawning grounds, hungry eagles and bears eagerly eat 24 salmon as they pass by. The bears will use the fat and protein the salmon provide to help them through the long winter's hibernation. ________ salmon are left to continue the journey. Recreational sport fishers catch another 14 salmon. This leaves ________ salmon to travel up the fish ladder constructed around a dam. The remaining salmon are tired and have traveled a long way. The final leg of the journey brings them to a waterfall. The salmon have to jump the falls to make it to the spawning grounds. Some of the salmon are too tired and 4 die. ________ salmon arrive at the place where they were born. These mature salmon have arrived at their home stream to spawn and it seems as if they will be successful! But a family out walking through the woods has come over to the stream to see the salmon run. They have let their dog run through the riverbed. What happens to the remaining salmon? Do they die before spawning? Or do they survive to produce a new generation of salmon? You decide: -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- --------------------------------------------------------------------------------
|