Altitude 0 - 200m
Description du site
The K'omoks IBA, along the east-central coast of Vancouver Island near the city of Courtenay, is an extensive network of marine waters, estuaries, backshore areas and associated lowland valley bottoms. Inland lowlands are a mixture of agricultural areas and forested land. Forests are predominately Coastal Douglas-fir and Western Hemlock while some dry Garry Oak/Douglas-fir forest occupies drier sites. An extensive estuary ecosystem extends from K'omoks Estuary through Baynes Sound to Deep Bay and Mapleguard Point, approximately 30 km to the southeast. Baynes Sound is a shallow coastal channel fringed by protected bays, open foreshore, tidal estuaries and inshore marshes. The shoreline includes wide expanses of mud and sand flats, low gradient deltas and sand and gravel beaches. This area is the most important intertidal area in B.C. for oyster and shellfish aquaculture. Further offshore, Lambert Channel and the marine waters surrounding Hornby Island have mostly rocky shores and rocky headlands, that provide extensive feeding and resting areas for waterbirds, especially during herring spawn in late-winter and early-spring.
The K'omoks IBA is an amalgamation of the former Comox Valley IBA, Baynes Sound IBA and Lambert Channel/Hornby Island Waters IBA. These three IBAs share common populations of waterbirds but were established as separate IBAs because they were nominated independently; follow the links to access the original site information.
Significant Species - This IBA supports six species at the global level: Trumpeter Swan, Surf Scoter, Western Grebe, Black Oystercatcher, Iceland Gull (Thayer's), Glaucous-winged Gull; and three species at the continental level: White-winged Scoter, Red-necked Grebe, and Mew Gull. Continentally significant numbers of Waterbirds occur each year and, in some years, continentally significant numbers for Brant and Long-tailed Duck.
Aggregations of 30,000-60,000 Waterbirds occur each year during herring spawn and over 100,000 were observed in March 2019. About a third to half of those waterbirds are waterfowl, including significant numbers of Surf Scoter, White-winged Scoter, and Long-tailed Duck in some years, and significant numbers gulls of Mew Gull, Iceland Gull (Thayer's) and Glaucous-winged Gull.
The Comox Valley is notable for the numbers of Trumpeter Swan that over-winter there. Following protection and recovery in the early 1900’s, the numbers of swans increased from the 1960s to an over-wintering population of about 2,100 birds but then declined to about 1,000 birds in recent years, which is still globally significant. The swans arrive in late October and have mostly departed by early April. They feed on various winter cover crops on farms as well as on native vegetation in the estuary.
Aggregations of Harlequin Duck gather at a few locations on the northeast side of Hornby Island during herring spawn. An estimated 3,400-5,500 birds were present in 1996-2001 but numbers have decreased to 1150-1250 birds in recent years. Historically, Western Grebe wintered here in globally significant numbers until the 1990s but then declined steeply. This significant decline has been noted throughout the Salish Sea (British Columbia and Washington); the reasons for the decline are not clear but may be related to a decrease in forage fish and a subsequent southerly shift in wintering areas. Recently numbers have increased again to globally significant numbers.
Other Species of Conservation Interest - The IBA supports important numbers of three species determined to be Threatened or Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC; wildlife species that have been assessed as at risk by COSEWIC may qualify for legal protection and recovery under Canada's Species at Risk Act). Great Blue Heron (fannini subspecies) (Special Concern, COSEWIC) has several colonies in the IBA (up to 100 individuals). Marbled Murrelet (Threatened, COSEWIC; Endangered, the International Union for Conservation of Nature, IUCN) occurs regularly in the IBA most of the year (peak counts of at least 50-100 individuals). Heermann’s Gull (Near Threatened, IUCN) is regular and up to 100 individuals and Peregrine Falcon (Special Concern, COSEWIC; Near Threatened, IUCN) winters regularly in the IBA and 1-2 pairs nest.
Enjeux de conservation
The number of people living in the IBA has doubled over the past 25 years and is expected to continue to increase. Impacts associated with increased development, including discharges from sewage and suburban storm sewers, wetlands being filled in, and new housing developments and associated commercial/industrial areas reduces the amount, and degrades the quality, of habitat for Trumpeter Swan and other waterbirds. Loss of soil-based agriculture also reduces habitat available for swans. From 1992 to 2002, at least 5% of the sensitive ecosystems and over 29% of modified ecosystems such as older second growth forests and seasonally flooded agricultural fields were lost to other uses. Disturbance from increased recreational activities also poses a potential threat to bird populations using the area.
Many of the species using this IBA are dependent on the Pacific herring spawn. Any activity that negatively impacts the herring spawn could have significant impacts on the ability of this site to support a concentration of birds. There is increasing concern that the current commercial harvest is not sustainable and there are calls for a moratorium or closure.
There is limited legislated protection in place for the marine waters; the most significant is the marine extension to Helliwell Provincial Park. On the uplands, there is a National Wildlife Area and several Provincial and Regional Parks, mostly forested habitat. Several areas of upland habitat are owned or managed for wildlife conservation, especially for Trumpeter Swan and waterfowl, by Ducks Unlimited Canada and The Nature Trust of British Columbia. As well, the Comox Valley Waterfowl Management Project (Ducks Unlimited Canada and Canadian Wildlife Service) is a cooperative farm and wildlife extension program established to maintain wintering waterfowl populations in harmony with successful farming.
The IBA is recognised in the Comox Valley Conservation Strategy (Nature Without Borders) and in some Official Community Plans.
Within the IBA, members of Comox Valley Nature have been conducting standardised bird monitoring for five decades: Christmas Bird Counts since 1961, Spring Bird Counts since 1976, weekly Trumpeter Swan Counts since 1990, as well as other bird counts. Volunteers also have been collecting monthly counts for the British Columbia Coastal Waterbird Survey since 1999 and monthly surveys for the British Columbia Beached Bird Survey since 2002.
Menaces Potencielles ou Existantes
Status de Protection