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Location Canada, British Columbia
Central coordinates 123o 7.26' West  49o 9.05' North
IBA criteria A4i, A4iii
Area 76,000 ha
Altitude 0 - 5m
Year of IBA assessment 2008

Bird Studies Canada/Nature Canada

Site description The Boundary Bay - Roberts Bank - Sturgeon Bank site is a large and complex area in southwestern British Columbia near the city of Vancouver. It includes Boundary Bay and the estuarine Sturgeon and Roberts banks, both of which are coastal wetlands and waters north and south respectively of the south arm of the Fraser River (which is also part of the site). Habitats found here include mudflats, and intertidal marshes predominantly composed of sedge, cattails and bullrush, which are critical to the Fraser River estuary ecosystem. The breakdown of detritus from marsh plants provides about 90% of the estuarine energy. The site also includes Point Roberts (USA) which separates the banks from the shallow Boundary Bay, Mud Bay and Semiahmoo Bay, all of which are more saline than the banks. At low tides, large mudflats form in the bays and extensive eelgrass beds are exposed. Finally, the fertile farmlands of Richmond, Delta, and south Surrey are part of this IBA. This site provides critical habitat for fish, such as the five salmon species, Herring, Coastal Cut-throat Trout and bottom fish species.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Brent Goose Branta bernicla passage  1999  4,751 individuals  A4i  Least Concern 
Trumpeter Swan Cygnus buccinator winter  1995  526 individuals  A4i  Least Concern 
American Wigeon Mareca americana winter  1995  30,500 individuals  A4i  Least Concern 
Red-necked Grebe Podiceps grisegena passage  1998  2,576 individuals  A4i  Least Concern 
Western Grebe Aechmophorus occidentalis passage  1998  3,000 individuals  A4i  Least Concern 
Western Sandpiper Calidris mauri passage  1992  500,000 individuals  A4i  Least Concern 
Dunlin Calidris alpina winter  1995  29,000 individuals  A4i  Least Concern 
Glaucous-winged Gull Larus glaucescens winter  1995  19,000 individuals  A4i  Least Concern 
A4iii Species group - waterbirds winter  500,000-999,999 individuals  unknown  A4iii   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Alaksen National Wildlife Area 299 protected area contained by site 360  
Alaksen Wetlands of International Importance (Ramsar) 586 protected area overlaps with site 1,000  
Boundary Bay Wildlife Management Area 12,191 protected area overlaps with site 11,000  
George C. Reifel Migratory Bird Sanctuary 648 protected area overlaps with site 400  
Peace Arch Provincial Park 9 protected area contained by site 8  


IUCN habitat Habitat detail Extent (% of site)
Forest Temperate coniferous forest; Temperate deciduous woods  -
Wetlands (inland) Estuarine waters; Freshwater marshes/swamps; Intertidal mud, sand or salt flats; Salt/brackish marshes  -
Sea Open sea  -
Artificial - terrestrial Arable land; Urban and industrial areas  -

Land use

Land-use Extent (% of site)
agriculture major
nature conservation and research minor
fisheries/aquaculture major
hunting major
tourism/recreation major
urban/industrial/transport minor

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Boundary Bay - Roberts Bank - Sturgeon Bank (Fraser River Estuary). Downloaded from on 23/10/2014

To provide new information to update this factsheet or to correct any errors, please email BirdLife