Inventory methods for sea asparagus in the Salish Sea: working with indigenous communities to integrate UAV technology and…

On the west coast of British Columbia, licences for the harvesting of sea asparagus are issued annually, requiring information on the baseline distribution and available biomass of the resource. While previous research has documented the biomass of sea asparagus in saltwater marshes of Boundary Bay and Cowichan Bay, this inventory is limited in geographic scope. Traditional ground transect survey methods are expensive and not feasible for expansion of inventory work across the Strait of Georgia. The use of small Unmanned Aerial Vehicles (UAVs) has gained recognition as a highly effective and accessible approach for mapping coastal vegetation. In this study, we developed and piloted a cost-effective methodology using UAV technology for the inventory of sea asparagus within a high priority area on the east coast of Vancouver Island. We combined field sampling methods with UAV surveys to provide ground-verified image coverage of saltwater marsh habitat. Photo-orthomosaics were used to produce a digital elevation model, from which area-based calculations for sea asparagus were developed. Area estimates were then converted to biomass based on ground-verification data. A key component of our approach was the involvement and participation of K'ómoks First Nation Guardian Watchmen. As stewards of their lands and waters, First Nation communities have a central interest in the management of commercial resources within their traditional territory. Indigenous-led UAV research provides the potential for new technology to benefit both ecosystems and communities.