Kelp forests are among the most productive marine ecosystems, supporting diverse wildlife communities whose welfare is threatened by warming seas, sea urchin overabundance, and coastal pollution.
Kelp forest welfare encompasses the diverse fish, invertebrate, and marine mammal communities that depend on this three-dimensional habitat. Sea otters foraging on sea urchins maintain urchin densities compatible with kelp growth; without otters, urchins overgraze kelp, creating bare urchin barrens that support minimal biodiversity. Individual fish expelled from collapsed kelp habitat face immediate predation exposure in open water. Sea otter recovery programs in California are demonstrating kelp recovery where otter populations have established.