Seaweeds, seagrasses, and the Island Chumash of Alta California

Unlike other Indigenous cultures around the Pacific Rim, ethnographic accounts suggest that the Chumash of California’s south-central coast generally did not eat seaweeds. Ethnographic records are also silent on Island Chumash technological use of seagrasses, although archaeological evidence for such use is widespread and dates back 10,000 years. Seaweed and seagrass remains are rarely preserved in Northern Channel Islands archaeological sites, but a growing body of direct and indirect evidence suggests that the Island Chumash regularly harvested them. Here, we report direct macrobotanical evidence from several Island Chumash sites for the harvest of seaweeds and seagrasses. At Limuw Cave (CA-SCRI-128), shell midden deposits dated between about AD 1450 and 1700 produced a variety of perishable plant materials, including redwood, numerous seagrass artifacts, and several types of edible marine algae. At several other Island Chumash village sites dated to the past millennium, carbonized fragments of kelps and other seaweeds were also identified among macrobotanical remains. Current archaeological evidence suggests that the Island Chumash regularly collected and consumed seaweeds. The abundance and wide variety of edible seaweeds found in Santa Barbara Channel waters add to the diversity of marine and terrestrial foods available to the Chumash, helping to explain their very large populations prior to European colonization, and reinforcing the notion that the Island Chumash had ample subsistence and other resources.