, image = Boundary Bay Regional Park in Tsawwassen.jpg , image_size = 260px , alt = , caption = Looking east across Boundary Bay from Tsawwassen , image_bathymetry = , alt_bathymetry = , caption_bathymetry = , location =

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, group = , coordinates = , type = Bay , etymology = , part_of =

Salish Sea , image = PNW-straits.jpg , alt = , caption = The Salish Sea, showing the open Pacific Ocean at lower left, and from there, heading inland: the Strait of Juan de Fuca, the narrow Puget Sound at lower ri ...

, inflow = , rivers = , outflow = , oceans = , catchment = , basin_countries =

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, agency = , designation = , date-built = , engineer = , date-flooded = , length = , width = , area = , depth = , max-depth = , volume = , residence_time = , salinity = , shore = , elevation = , temperature_high = , temperature_low = , frozen = , islands = , islands_category = , sections = , trenches = , benches = , cities = Blaine, Delta, Surrey, White Rock , pushpin_map = British Columbia , pushpin_label_position = , pushpin_map_alt = , pushpin_map_caption = , website = , reference = Boundary Bay is a shallow bay situated on the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

coast of North America on the Canada–United States border between the Canadian province of

and the

U.S. The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

state of

Geography

Boundary Bay is bounded to the east by the city of Blaine in Washington and the cities White Rock and Surrey in British Columbia. It is also bounded to the east by the reserves of the

Semiahmoo First Nation Semiahmoo First Nation ( ) is the band government of the Semiahmoo people, a Coast Salish subgroup. The band's main community and offices are located on the Semiahmoo Indian Reserve which is sandwiched between the boundary of White Rock, Brit ...

in British Columbia. To the north, it is bounded by the City of Delta. To the west, it is bounded by the Tsawwassen Peninsula, which contains the communities of Tsawwassen (a suburb of Delta) and

Point Roberts, Washington Point Roberts is a pene-exclave of Washington on the southernmost tip of the Tsawwassen peninsula, south of Vancouver, Canada. The area, which had a population of 1,191 at the 2020 census, is reached by land from the rest of the United States ...

(a pene-exclave of the

). To the south, it is bounded by the Strait of Georgia, the northern arm of the larger

. The eastern section of Boundary Bay straddling the US/Canada border and adjacent to the cities of White Rock and Blaine is known as

Semiahmoo Bay Semiahmoo Bay ( ) is the southeastern section of Boundary Bay on the Pacific coast of North America. The bay is named for the Semiahmoo First Nation, who originally occupied the area. The Semiahmoo Peninsula borders the bay and was home to canne ...

; Blaine's Drayton Harbor opens into it. The northern tip of Boundary Bay is known as Mud Bay.

Inflows

The main rivers flowing into the bay are the Nicomekl and Serpentine Rivers falling into Mud Bay, the Campbell River falling into Semiahmoo Bay, and California Creek and Dakota Creek falling into Drayton Harbor.

Ecology

It is an important stop for birds migrating along the

Pacific Flyway The Pacific Flyway is a major north-south flyway for migratory birds in the Americas, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading ...

, particularly for

western sandpiper The western sandpiper (''Calidris mauri'') is a small shorebird. The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-coloured waterside birds. The specific ''mauri'' commemorates Italian bota ...

and dunlin, and has been designated a Hemisphere Reserve by the Western Hemisphere Shorebird Reserve Network and a Canadian Important Bird Area. The mudflats, extensive

eel grass Eelgrass is a common name for several plants and may refer to: * ''Zostera'', marine eelgrass * ''Vallisneria ''Vallisneria'' (named in honor of Antonio Vallisneri) is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass o ...

beds and

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is domin ...

es support a rich population of marine

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s which are an important source of energy for migrating

shorebird 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

s. During migration times the bird count in the bay may exceed 100,000

Pollution and industrial activity in the area pose potential threats to wildlife.

Conservation

On June 21, 1995, the entire Canadian portion of Boundary Bay was protected within the Boundary Bay Wildlife Management Area.

Activities

The area is also used for recreational boating and includes park area and beaches. The Boundary Bay Airport, on its north flank, is used by small aircraft and has been the setting for various film shoots.

References

External links

Birds on the BayFilm footage of Centennial Beach in 1958A Nature Guide to Boundary Bay
Author's Site.

Photographer's Site. {{British Columbia hydrography Bays of British Columbia Bays of Washington (state) Landforms of Lower Mainland Bodies of water of Whatcom County, Washington Delta, British Columbia Surrey, British Columbia White Rock, British Columbia Important Bird Areas of British Columbia