Do sea urchins get energy by eating kelp

How sea urchins get energy: Sea urchins eat using a structure called Aristotle's lantern. It is made up of five hard plates that come together like a beak. They use their beak-like mouth to scrape rocks clean of algae. Sea urchins will eat just about anything that floats by.

Do sea urchins eat kelp?: These animals feed on the holdfasts that keep kelp anchored to the bottom of the ocean and algae that are abundant in kelp forests. Sea urchins will often completely remove kelp plants by eating through their holdfasts. The sea otter eats the red sea urchin that can destroy a kelp forest if left to multiply freely.

Yes, along with a lot of other things.