Investigating Coastal Resiliency in Managed vs. Unmanaged Foredunes in Humboldt Bay, California

Abstract

Coastal communities are under increasing pressure from sea level rise and storm surges amplified by anthropogenic climate change. In Northern California, Humboldt Bay endures the fastest rates of sea level rise in California. Foredunes provide an array of ecosystem services, including protection to inland communities, but poor management and the presence of invasive species have led to further widespread erosion along the coast. This project involves a series of 73 cross-shore foredune profiles, monitored biannually from Summer 2016 to Winter 2020. Of the 73 studied foredune transects, 57 foredune transects are managed at the local, state, or federal level. This study compares foredune functionality in managed areas, which are often natively vegetated, to foredunes in unmanaged areas, which are often invasively vegetated. Results and associated implications suggest that natively vegetated dunes have a more rapid response to erosional events and thus perform enhanced resilience against climate change. Foredune management and restoration with native foredune vegetation is necessary for the protection, well-being, and prosperity of the Humboldt Bay community. The results imply that land conservation and sustainable practices are ideal for achieving optimal natural world functions for resilience against climate change.