California mussels were an important food source for the Native Americans who lived on the Pacific Coast prior to European contact. On California's Northern Channel Islands, archaeological evidence shows that they were harvested continuously for almost 12,000 years. Erlandson et al. (2008) documented a decline in the average size of harvested California mussels on San Miguel Island during the past 10,000 years, a pattern they attributed to growing human populations and increased predation pressure from human fishing. Hogan (2008) notes more specific archaeological recovery from the Chumash in the period 800 to 1300 AD.