|The Ecological Importance of Boundary Bay and the Fraser Delta
Boundary Bay is a shallow marine bay that lies just south of Vancouver, British
Columbia and straddles the BC - Washington State border. It is part of the Fraser
River estuary, although its habitat is more marine than other parts of the estuary, as it
is separated from the mouth of the river by the Tsawwassen - Point Roberts
The bay is a renowned wildlife habitat, being one of the few lowland marshy areas on
the mountainous BC coast. It is particularly known for its bird life, but the waters of the
bay and the adjacent Georgia Strait are rich in marine life that includes grey whales,
endangered southern resident killer whales, humpback whales, porpoises, seals
and sea lions, in season. Fraser salmon gather in the Fraser River estuary on their
way up the river to spawn.
Boundary Bay lies on the Pacific Flyway migration corridor between the Arctic and
Central and South America. It is visited by millions of birds every spring and fall, and
hundreds of thousands of ducks and geese winter in the area.
Up to 50 species of shorebird have been recorded here, and some species such as
the western sandpiper, least sandpiper, black-bellied plover and dunlin, occur in high
numbers during migration. Plovers and dunlin can also be found here in winter.
Boundary Bay is also the most important location in Canada for numbers and diversity
of wintering birds of prey (raptors) and is a magnet for birders in search of owls. In
some winters it is possible to see snowy owl, great horned owl, barred owl,
short-eared owl, barn owl and northern sawhet owl on a single day.
The Annex site on this website has checklists for the key birding locations around
Boundary Bay, as well as plant and tree lists available for download.
Boundary Bay is one of three key component sites of the Fraser River Delta and
Estuary Important Bird Area. Together with Roberts Bank and Sturgeon Bank, it
ranks highest among the nearly 600 Important Bird Area sites in Canada for the
diversity and number of species reaching global thresholds. It is considered to be
among the top 20 wetland sites in North America.
The Important Bird Area program is an international, cooperative initiative organized by
BirdLife International partners around the globe. In Canada, the program is
coordinated by Nature Canada and Bird Studies Canada. In British Columbia, the
lead partner is BC Nature (the Federation of BC Naturalists).
Boundary Bay, including Roberts Bank and Sturgeon Bank, is a Western
Hemispheric Shorebird Reserve Network Site. The WHSRN program is an
international, cooperative initiative to protect shorebirds and their habitat along the
To find out more about wildlife in and around Boundary Bay, read A Nature Guide to
Boundary Bay. More information on stewardship programs and outings can be found
on the Birds on the Bay site and on the list of links to local clubs, agencies and