Intertidal Healing

A constellation of Ochre Sea Stars (Pisaster ochraceus) doing their duty as the keystone species in the intertidal zone off the northwest coast of North America.

A keystone species is an organism that has a overwhelming impact on the health and

viability of a particular ecosystem. The Ochre Star does this by being the major predator of the California Mussel (Mytilus californianus). Without the Ochre Stars, beds of mussels will completely overtake the intertidal region and choke out the wide diversity of intertidal

life like anemones and urchins.

Unfortunately starting in 2013 a horrific disease decimated Northeast Pacific sea stars in one of the largest animal die offs ever recorded with Ochre Stars being particularly hard hit. While the exact pathogen of the disease is still being

determined, a large blob of warm water in the NE Pacific that appeared at the same time was likely the driving force behind the outbreak by reducing the ability of the sea stars to resist the illness and creating an environment more favorable for the cause of the disease. The

sudden loss of sea stars in the intertidal zone unfortunately turned large swaths of tidepools into gigantic mussel beds crippling the health of the intertidal zone.

The good news is that there have been signs recovery in Ochre Sea Stars and they are hard at work restoring

their domain to its full glory. I am hopeful their populations and the populations of other sea stars will continue or begin to recover in the future.