Fighting for food and space - a gym activity
Life as a young salmon in the river is hard. Here they fight each other for both food and space. The danger of being eaten is always lurking.
Competency goals for grade 7, science
- ask questions and make hypotheses about scientific phenomena, identify variables and collect data to find answers.
- explore and describe different food webs and use this to discuss interactions in nature.
Playing salmon fry is a busy business.
Here's what you need to know first
Life as a baby salmon is tough and many die. That's how it should be.
The number of juvenile salmon in a river depends on how many hiding places there are and whether the juvenile salmon have access to enough food. For as many wild salmon as possible to return from the sea to spawn, all the hiding places in the river must be occupied by salmon chicks that have access to enough food. It is natural that many die on the way from egg to adult salmon.
Baby salmon do not "hang out" with each other
Baby salmon (salmon parr) are territorial. This means that they want their hiding place for themselves and defend it. We can say that the hiding place is the chick's territory. Another name for territory is territory.
Description of the activity
Lay out as many rock rings or circles of rope as there are pupils (young salmon). These are hiding places for the young salmon. There should be benthic animals (food for the young salmon) between the rings. Cones, stones, dried peas or similar can be used as substrate. There should be five anchovies for each young salmon participating in the game.
Choose a pupil to be an otter or other animal that likes to eat baby salmon.
The rest should be salmon chicks. When all the salmon chicks are in place in their respective rings, the game begins. The salmon chicks must leave their circle to get food. They are only allowed to collect one piece of food for each trip out of the ring. It's a matter of collecting as much food as possible without being caught by the otter. Remember that the circle is the salmon chick's hiding place, and thus a free area. You cannot be caught here.
Set aside a limited amount of time for play.
Salmon chicks that have caught at least four benthic animals without being eaten by otters are all winners. They can smoltify and go to sea!
Task related to the activity
The spawning can be varied with more young salmon than there are rings, more and fewer fish-eating animals, fewer benthic animals, and so on.
Between each time you change something, you can discuss the result of the game and compare the result with the previous time. Discuss why the results change from time to time.
Otters love salmon
Otters prefer to get hold of slightly larger salmon and can catch and eat spawning salmon in the river.
For the teacher
We recommend playing in a larger, open space.
If you want to get something extra out of the game, we recommend that you use the registration form below. Here you can note down the result for each round. Remember to note any changes you make to the setup.
Then you can discuss the outcome of each round based on the changes that were made. Were the results as expected?
Good luck!
Student booklet
The Nasjonalt villakssenter works for a stronger wild salmon and wants to promote the stream as an educational resource. Bring experiences from the classroom and put them in context with experiences outside. Many schools in Norway have a local stream. Even in our largest cities, there are streams that can be visited. Contact us for assistance, tips and professional support.
The student booklet "Who lives in your river?" can help with both preparation and follow-up work.