Lambert Channel/Hornby Island Waters (BC061)
Altitude 0 - 10m
Description du site
Comox Valley IBA, Baynes Sound IBA and Lambert Channel/Hornby Island Waters IBA share common populations of waterbirds but were established as separate IBAs because they were nominated independently. In 2013, these sites were amalgamated into the K'omoks IBA; follow this link for current information for this area.
Lambert Channel is the body of water that separates Denman and Hornby Islands. These islands are located off the east coast of Vancouver Island in the central part of the Strait of Georgia. Within Lambert Channel, the IBA extends several kilometres along the entire northern shore of Denman Island (including the Seal Islets), and the northwestern, western, eastern and southern shores of Hornby Island. The shores of the channel are a mixture of gravel and rock, with the water currents in the channel being influenced by tides twice daily. The upland habitats adjacent to the channel are part of the dry Garry Oak/Douglas fir forests that are restricted in British Columbia to the Strait of Georgia. Hornby Island is forested with Douglas fir on the southeast peninsula, and has mostly rocky shores, culminating in a large rocky headland (St. Johns Point) at the tip of this peninsula. The waters within 2 km of the shores of Hornby Island are included in the IBA.
Birds concentrate in the Lambert Channel to take advantage of spawning herring, which are usually present during the first few weeks of March. Significant numbers of waterfowl, especially Surf Scoter, White-winged Scoter, and Long-tailed Duck, and significant numbers of waterbirds, especially Glaucous-winged Gull, Mew Gull and Thayer's Gull, are found at this time. As well, continentally important numbers of Black Brant occur during spring migration. Lambert Channel and the waters off of Hornby Island support significant concentrations of Harlequin Duck in more than one season. Aggregations of Harlequin Duck gather at a few locations on the northeast side of Hornby Island for 2-3 weeks during herring spawning. These aggregations can include 49-81% of the midwinter population of Harlequin Duck in the northern Strait of Georgia. An estimated 3400-5500 birds were present in 1996-2001. Aggregations occur in only a small fraction of the habitat area where spawn is available, indicating the importance of the site. During summer and early fall, the shores of Hornby Island are also a major roost site for moulting Harlequin Duck. The relative importance of the IBA to the other species listed in the table below is under review.
Enjeux de conservation
Lambert Channel and the waters surrounding Hornby Island have long been recognized as an important area for waterbirds and herring. Any activity that negatively impacts the herring spawn (e.g. reductions in water quality, foreshore development) could have significant impacts on the ability of this site to support a concentration of birds. Disturbance from increased recreational activities also poses a threat to bird populations using the area. The recent demand for expanded mariculture development will need to be monitored carefully for its impact on birds. There is limited protection in place, particularly for the marine waters; the most significant is the marine extension to Helliwell Provincial Park.
Menaces Potencielles ou Existantes
Status de Protection