A robust collection of mammal, bird, fish, and shellfish remains from an 8,000-year residential sequence at Morro Bay, a small, isolated estuary on the central California coast, shows a strong focus on marine species during the Middle-Late Transition cultural phase (950–700 cal B.P.), which largely coincides with the Medieval Climatic Anomaly (MCA). Previous studies have provided modest evidence for increased fishing and rabbit hunting during the MCA in adjacent regions, but the Morro Bay findings suggest a distinctive marine-focused subsistence refugium during the period of drought. Specifically, the sequence shows striking all-time peaks in marine and estuarine birds, fish NISP/m3, and fish/deer + rabbits during the MCA. Heavy exploitation of fish, aquatic birds, rabbits, and shellfish suggests that the bow and arrow, which seems to have arrived in the area at this time, had little impact on local subsistence strategies.
A pluvial episode identified in arid Australia during the Medieval Climatic Anomaly
