Keystone species
Updated: 6/4/2020
Keystone species

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  • I’m great, but I’m a little concerned about our ecosystem here in Makkah Bay.
  • Hi Tom, how are you doing today?
  • We are a little concerned too. With all the starfish gone the mussel population is really thriving and it’s scaring us.
  • I recently learned that the starfish are a keystone species. What does that mean?
  • I’m pretty sure the removal of those starfish caused a Trophic Cascade.
  • Keystone species are parts of the ecosystem that control the population under them in the food chain.
  • What is a Trophic cascade?
  • A Trophic Cascade is a top down effect which shows the affect of the removal of a single organism from that ecosystem.
  • The effects of this can be positive or they can harm the entire population.
  • Was the effect here in the bay positive or negative?
  • We’re coming over guys and we can help explain the situation.
  • Well, that varies based on if you were the starfishes predators or pray.
  • When the starfish were removed from the ecosystem the starfish’s pray were able to flourish. Without a predator the mussels population grew unchecked.
  • This had a negative effect on the prey of the mussels as they now had lots more predators. Removal of a keystone species hurts the food chain.
  • I can’t believe that the King crabs eating all the starfish could hurt our ecosystem so much. We need populations to grow checked so they don’t harm other populations
  • Keystone species and Trophic cascades can have extreme impacts. Let’s work together to protect the starfish so their populations can once again rise to a normal level.
  • Together we have the power to help restore our beautiful ecosystem.