Keystone

What role do keystone species play in an ecosystem, and can you provide an example of one?

Keystone species play a critical role in an ecosystem by exerting a disproportionate influence on its structure and function. They help maintain biodiversity and ecological balance. An example is the sea otter, which, by consuming sea urchins, prevents overgrazing of kelp forests, supporting a diverse marine ecosystem.

A keystone species is an organism that helps define an entire ecosystem. By keeping populations of mussels and barnacles in check, this sea star helps ensure healthy populations of seaweeds and the communities that feed on them—sea urchins, sea snails, limpets, and bivalves.