Fish trap model

Use playdough and a marble in a tray, to understand how a fish trap works.
Science content
Biology: Indigenous People's sustainable use of Living Things (K, 2, 3)
Earth/Space: Indigenous People’s Traditions around Sky, Land and Seasons (K-7)
Lessons activity is in
    per student:
  • shallow white tray e.g. IKEA
  • ball of play dough
  • marble

Describe how Coast Salish Indigenous people, and people around the world today and in the past, make traps in rivers to catch fish.
They are used seasonally, when fish are migrating up rivers.

Fish traps are placed where adult fish return upriver to spawn. Fish traps guide the fish through a maze of walls and compartments, and since migrating fish tend to move ahead and rarely turn backward, they end up in compartments that they cannot escape from. People can wade into the river and use a net to scoop the fish from the trap.
Fish traps are sustainable, as the fish are not damaged in the trap, and fish that are unwanted can be moved back into the main river. (gillnets or seines damage fish as they become wedged and lose scales).

Demonstrate to students how the activity will work.
The marble is a fish, and they will roll it around the tray, like a fish swimming in a river.
They roll the play dough into sausages and stick them to the bottom of the tray, to make shapes that will trap the rolling marble.
By forming passages with the playdough that funnel the marble to one end of the tray, but have a narrow opening which makes it hard for the marble to roll back, the model shows how fish traps work.

Either before or after the activity, show students photographs/videos of fish traps:
Photos of Squamish First Nation fish traps made from rocks on the Capilano River:… and
Video of a fish trap made from rocks by Alaskan Inuit, with explanation of how it is repaired and used, within a 15 minute story.
Photo of an Alaskan fish trap made from wooden stakes, with woven mats below the water line:
Drawings and photos of a Fish trap in Comox valley, showing remains of the wooden poles.… (Poles, made from Douglas Fir saplings, pounded into the sand, in a shape that drove fish into the trap. These poles remained there year round. Woven panels were lashed to the poles when the trap was in use.

Grades taught
Gr K
Gr 3
Gr 4
Teaching site
Selkirk Elementary
Shaughnessy Elementary
Prototyped only (not yet run in a classroom)