The historical ecology of coastal California

Humans have been an integral part of California's marine and coastal ecosystems for over 13,000 years. While the region is one of the best studied marine systems in the world, a historical perspective that connects social -ecological dynamics of change across California's diverse cultural periods is lacking. Historical ecology offers a lens through which researchers and managers can use historical information to not only better understand the complex dynamics that have driven ecosystem change in the past, but also inform crucial decisions around conservation and sustainable management of these systems into the future. Here we synthesize historical esti-mates of population abundance of eleven key species and habitats across coastal California as a foundation for understanding the potential for decline, recovery, or reorganization inherent in these ecosystems. This millennia -scale historical perspective reveals that humans have played a significant role in shaping California's marine ecosystem dynamics for far longer than is traditionally accounted for in many restoration and management contexts. Each individual cultural period reviewed here paints an increasingly complex story of social-ecological interactions and impacts, with each time period intricately tied to the trajectory of the last. As we consider management actions in an increasingly unpredictable future, information around how these systems have his-torically responded to new and growing pressures may prove invaluable to their future sustainability. While historical baselines may not provide a realistic, or even desirable, model for future sustainability, they may offer important insights into the social-ecological potential for change and recovery moving forward.