Sea-level rise threats to food security: A review of agrifood system resilience in the Lower Fraser Valley, BC

Sea-level rise (SLR) is an accelerating global process that alters coastal hydrodynamics and salinity gradients, generating risks that extend beyond shoreline inundation. In the Lower Fraser Valley (LFV) of British Columbia, SLR interacts with climate-driven shifts in Fraser River discharge and shallow, tidally influenced coastal aquifers to transform freshwater availability and quality for agriculture, ecosystems, and communities. This review synthesizes hydrogeological, climatic, ecological, and socio-economic evidence to evaluate how SLR-driven processes (saltwater intrusion (SWI), inland salt wedge migration, groundwater emergence, and soil salinization) cascade through the LFV agrifood system as a coupled social-ecological system. We integrate available vulnerability mapping and demographic indicators to contextualize spatial exposure in low-lying municipalities and identify how risks concentrate in areas with high agricultural value, subsiding landforms, and hydraulically connected surface-groundwater networks. The synthesis indicates that declining summer discharge reduces the Fraser River estuary's freshwater buffering capacity, prolonging saline conditions that constrain irrigation reliability, degrade soil function, and increase management costs for high-value crops. Simultaneously, salinity- and discharge-mediated habitat change threatens estuarine ecosystem functions and culturally significant fisheries, with implications for Indigenous food sovereignty and community well-being. Evaluating adaptation strategies through a social-ecological resilience lens highlights the limits of recovery-oriented, asset-protection approaches under non-stationary SLR and emphasizes leverage points for strengthening resilience: integrated salinity monitoring linked to drought decision-making, reinforcement of ecological buffers, and inclusive governance that addresses distributional vulnerability while recognizing Indigenous food systems as equal systems with distinct rights and stewardship responsibilities. Collectively, the review provides an integrated evidence base to support equitable adaptation and longer-horizon transformation planning in one of British Columbia's most productive and climate-exposed agrifood regions.