Baynes Sound is situated between the east coast of Vancouver Island and Denman Island in the Strait of Georgia in southwestern British Columbia. This site extends from the Courtenay River estuary at the head of Comox Harbour, to Deep Bay and Mapleguard Point, approximately 35 kilometres to the southeast. Chrome Island is situated off the southern point of Denman Island, and is also included in the IBA. Baynes Sound is a shallow coastal channel fringed by protected bays, open foreshore, tidal estuaries, inshore marshes and adjacent forests. Comox Harbour, which bounds Baynes Sound on the northwest, is a large low gradient deltaic deposit. Together these protected waters and their many freshwater streams function as a single estuary. The shoreline, much of which is in a relatively natural condition, ranges from wide expanses of mud and sand flats to rocky shorelines overlooking deep water. The key habitats are a series of low gradient deltas, sand and gravel beaches, tidal flats, estuaries and foreshore. The Sound has several small bays that support a shellfish industry, that comprise the most important area in the province for oyster mariculture. The surrounding land is a mixture of undeveloped second growth forest, areas of commercial pasture and cropland, small farms, urban and suburban development and light industry.
The Baynes Sound area is important for winter populations of waterfowl and shorebirds, and for summer-moulting seaducks. The presence of spawning herring during early spring is an important food source for many bird species occurring in the area. Maximum single day counts at this site during surveys in 1980 1981 recorded significant numbers of the following species (unless noted otherwise the percentage of the estimated global population is in parentheses): Pacific Loons (2% of a conservative North American estimate), Western Grebe (at most 8%), Great Blue Heron (ssp. fannini 2%), Trumpeter Swan (1% of the Pacific population), Brant (4% of the western ssp. nigricans), Black Turnstone (4%), Mew Gull (2.5% of North American population), Thayer's Gull (2%), Glaucous-winged Gull (>1%). Additionally, over 2% of the estimated national population of Pelagic Cormorants were recorded at this site.
Other birds recorded at this site include 138 Common Murres, 426 Black-bellied Plovers, 350 Bald Eagles, as well as concentrations of more than 50 Marbled Murrelets (nationally threatened). Ten gull and tern species, 19 species of shorebirds, 16 species of diving ducks (such as White-winged, Surf and Black scoters), nine species of dabbling ducks, and 13 species of raptors have been recorded in the Baynes Sound area. Concentrations of diving ducks have reached 12,185.
Conservation responses/actions for key biodiversity
Baynes Sound has long been recognized as an important area for waterbirds, salmon, herring and shellfish. There is a proposal in progress by the BC Ministry of Environment to designate Baynes Sound a Provincial Wildlife Management Area. The east coast of Vancouver Island has experienced rapid housing development in the past few years. The greatest threat to birds in the Baynes Sound/Comox Harbour area is the destruction or degradation of habitat (in particular coastal wetlands) by urban development. Runoff from sewage and suburban storm sewers threaten the water quality of Baynes Sound. Disturbance from increased recreational activities also poses a threat to bird populations using the area.