Open Collections

Janus, Dominic

University of British Columbia

Management of invasive and hyperabundant species requires adaptive solutions that support conservation and promote human-wildlife coexistence. Increasing herbivory by rapidly growing populations of introduced Canada Goose (Branta canadensis; CAGO) in the Fraser River Estuary (FRE), British Columbia, Canada, threatens the ecological function of its tidal marshes which support many species at risk of extinction. My research addresses knowledge gaps on the status of introduced CAGO in the FRE and their ecological impacts, in particular on Lyngbye’s sedge (Carex lyngbyei), and identifies potential management responses that support marsh conservation. Lyngbye’s sedge is a foundational plant species within the FRE providing both structural integrity to the marsh and significant inputs to estuary food web productivity. I monitored Lyngbye’s sedge in exclosed (protected from CAGO) and open (unprotected) plots across the FRE over two years to assess CAGO herbivory effects on sedge height, density, and flowering. During the two-year study, I found that sedge height, density, and flowering rate benefited from the protection from goose herbivory. Management of CAGO in an urban setting such as the FRE presents significant challenges. To identify feasible CAGO management options I undertook a review of contemporary CAGO management and Indigenous stewardship of geese. The importance of the latter was brought to my attention through firsthand involvement in Indigenous-led CAGO management on Vancouver Island as well as the history of waterfowl stewardship by Coast Salish Peoples in the Fraser Estuary. My review revealed that integrated methods of CAGO harvest can effectively mitigate ecological impacts and provide co-benefits such as food. The review also emphasized the importance of collaborative development and alignment of management objectives with community values. Evidence of the positive ecological effects of reducing CAGO herbivory in the FRE together with practical insights for integrated management can increase the capability of managers to respond to the many cumulative threats to these ecosystems and support habitat protection and recovery for species at risk. To this end, my research suggests that increased harvest of introduced CAGO in the FRE can support conservation and potentially align with Indigenous food sovereignty initiatives.

Text

2024-08-01

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88835

Forestry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/