I’ve mentioned in a previous BPotD entry that the waters of the northeast Pacific contain more species of kelp than anywhere else in the world. Today’s photographs illustrate another member of that diverse group, southern stiff-stiped kelp (by the way, there are no search engine results for northern stiff-stiped kelp, so I think stiff-stiped kelp should suffice as a common name). Ecologically, this alga grows from the low intertidal zone on open rocky shores to complete submergence, where it can sometimes be an understory species in kelp forests.
Decew’s Guide once again provides some background and references: Laminaria setchellii. The photo gallery at Algaebase provides a more conventional presentation of this species, if you’d like to investigate.