Sea urchins feed on the algae that compete with the corals ... following the notorious 1983 sea urchin population collapse there, which led to the catastrophic phase shift of the coral reef.

"We first started to see these dramatic images of sea urchins feeding on the kelp in 2018 and even more in 2019." The sea urchin-kelp dynamic has been well-studied, but this is the first study ...

Sea urchin is a delicacy in many parts of the world ... where farmers are now feeding their urchins with greens.