What do salmon eggs need to survive?

Essential Question: What do salmon eggs need to survive?

If you have not already completed that assignment, go do that before you continue!

​Last week, we watched an Edpuzzle about the Salmon Life Cycle

This week we are going to learn about what salmon need to be able to grow and thrive

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Egg

Let's start at the beginning with the Egg stage

Salmon Egg Info

• Laid in fresh water in the fall (in rivers or streams)

• One female salmon can lay 1,000 eggs or more

• Stage lasts around 12 weeks

Multiple Choice

About how many weeks does the egg stage last?

• 2 weeks

• 12 weeks

• 4 months

• 1 year

At the egg stage, salmon have two main needs from the water they live in.

• Temperature

• Water Flow

What is temperature?

Temperature is the degree or intensity of heat present.

Something that feels hot will have a higher temperature than something that feels cold.

Temperature

The amount of time it takes for salmon eggs to hatch depends on the temperature of the water.

Temperature

If the water is too warm, the salmon eggs will develop too quickly.

If the water is too cold, the salmon eggs will develop too slowly.

Either of these conditions can cause the salmon eggs to die.

Multiple Choice

What can happen to salmon eggs if the water isn't the right temperature?

• They will be healthy and strong

• Nothing will happen

• They could die

What is the right temperature?

The ideal temperature for raising salmon eggs is between 42*F and 55*F.

Multiple Choice

The current temperature of the Willamette River is about 43*F.

Is this an ideal temperature for salmon eggs?

• Yes

• No

What keeps the water the right temperature?

• Run off from melting snow

• Underground water

• Shade from trees and plants

Open Ended

Shade from trees and plants along the shore is one thing that helps keep rivers and streams the right temperature.

What do you think would happen to salmon eggs if the trees and plants were removed?

Flow

The amount of water moving in a unit of time.

Why is flow important?

- Flow brings in fresh, clean water with lots of oxygen

- Removes waste

- Helps maintain the temperature of the river

What affects flow?

• The amount of water entering the river from run off

• Anything that blocks the natural path of water, like a dam

What is a dam?

A dam is a structure built across a river or stream to hold back water. They can be used to create energy.

How do dams affect salmon eggs?

Dams change the natural flow of water through a river. This causes a lot of changes to the entire river ecosystem.

How do dams affect salmon eggs?

Dams can raise the temperature of water because it no longer flows freely throughout the river. This also means that the salmon eggs would not get fresh, clean water at the same rate they naturally would.

Multiple Choice

How do dams change the water temperature in rivers?

• Dams make rivers warmer

• Dams make rivers colder

• Dams don't change the temperature

Multiple Choice

If there was less water entering the river, would that increase the flow or decrease the flow of water through the river?

• Increase

• Decrease

Multiple Choice

What do you think would happen to salmon eggs if there was less water flowing through the river?

• Nothing would happen

• They would be healthier

• They would be more likely to die