The Stefansson Sound Boulder Patch, located 20 km northeast of Prudhoe Bay in the Alaskan Beaufort Sea, supports the only known kelp bed on the Alaskan arctic coast that is characterized by high benthic diversity associated with an abundance of boulders, cobbles, and pebbles. Growth and production of the endemic arctic kelp Laminaria solidungula, which is abundant throughout the area, is regulated primarily by PAR (photosynthetically active radiation) availability during the summer open-water period. Variation in underwater PAR, caused by changes in water transparency, can have significant effects on the annual productivity of this species (Dunton, 1990).