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Biomagnification Tag

Biomagnification refers to the concentration of a substance in the system of an organism at successively higher ranks in the food chain. As larger species like seals, sharks, and whales rely on fish for their food, there is a greater likelihood that the amount of plastic in their body will increase as plastic pollution in our oceans becomes more urgent. This activity will seek to show the dangers of biomagnification and why it is important to reduce plastic use.

Biomagnification Tag


Biomagnification refers to the concentration of a substance in the system of an organism at successively higher ranks in the food chain. As larger species like seals, sharks, and whales rely on fish for their food, there is a greater likelihood that the amount of plastic in their body will increase as plastic pollution in our oceans becomes more urgent. This activity will seek to show the dangers of biomagnification and why it is important to reduce plastic use.  


Materials needed: 

  • Small bits of plastic such as bottle caps, wrappers, zip-ties, or strips from bottles.  

  • Open space 

Roles: 

  • Krill (majority of players) will receive a random amount of plastic scraps. Since krill are at the bottom of the food chain, they will run from the salmon. Once tagged, the krill will link arms with the salmon.  

  • Salmon (4-5 players) will tag krill in the first round of the game, linking arms with their prey once tagged.  

  • Fishermen (2-3 players) will tag salmon in the second round of the game, after all the krill are "eaten," mimicking the higher level in the food chain. 

Debrief: 

  • Once everyone has been tagged, the groups should gather to count the plastic accumulated. Krill will report the plastic they were initially given. Salmon should count all the plastic passed on from each krill they tagged. Fishermen should count all the plastic each of their salmon had.  

Discussion: 

  • What did you notice about the game? Who won? 

  • What do the pieces of plastic signify? How did the fishermen end up with the most? 

  • Why is the concept of biomagnification important? Why does it matter to the health and habitat of every species involved? 

  • Do you think that plastic is the only danger? What other types of pollution might have the same effects and consequences? 



Source: Biomagnification_Game.pdf (sailorsforthesea.org) 

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