Abstract
Tidal marshes are a hub of biodiversity and provide a range of ecosystem services, in addition to cultural and economic values. This project focuses on tidal marshes in the Skeena River Estuary, near Prince Rupert, British Columbia, a major port city that continues to experience development impacting a variety of wetland ecosystems. This project creates a framework to prioritize sites in the Skeena River Estuary for marsh expansion or creation, as a means of offsetting the degradation of local wetlands. The objectives were: 1) characterize the tidal marshes of the Skeena River Estuary study area; 2) create a framework to identify, rank and prioritize candidate sites for assisted tidal marsh expansion; and 3) propose sites for a tidal marsh expansion pilot project with potential techniques and designs for implementation in the Skeena River Estuary. Twentyfour sites were assessed, and six were selected and characterized through completing vegetation surveys and collecting elevation and sediment data. This information was fed into the created two-part framework, which uses Multi-Attribute Utility Theory to identify key environmental and sociocultural metrics, and scores each site using an adapted Five-Star Recovery table from the Society for Ecological Restoration. Ten key metrics were identified for the Skeena River Estuary: icrotopographic elevation, eulachon spawning habitat, historical marsh expansion, presence of native species, proximity of propagules, invasive species, impediments to access, habitat area, method of transport, and site access. Site 1B at the confluence of the Skeena and Khyex Rivers was identified as the best site for marsh expansion, with a high score in ease of access and a lower score for invasive species, presenting an opportunity for proactive action and marsh expansion. The developed framework can be adapted to a variety of goals and regions, aiding in selecting key metrics for project assessment based on capacity and funding, and ranking priority sites as output.