Waterfowl

Carpenter Lake Reservoir is the largest of the three reservoirs of the Bridge River Power Project (about 50 kilometers in length). It is a mid-sized stream approximately 120 km long, flowing south-east from the snowfields of the Coastal Mountains and joining the Fraser River near South Chilcotin. The lake is about 185 kilometers north of the province's major city of Vancouver and is formed by the diversion of the Bridge River by Terzaghi Dam into Seton Lake via a tunnel through Mission Mountain, which separates the Seton and Bridge drainages. Carpenter Lake is about 50 kilometres in length, and represents a major riparian habitat for the region. This structurally complex area welcomes a diversity of vegetation species, and supports rich communities of breeding birds: Canada Geese, Snow Geese, Ross's Geese, Mallards, Pintails, Harlequin, Canvasback, and Goldeneye. The riparian habitats are a relatively rare landscape features (Skagen et al. 2005): in western North America, they comprise less than 1% of terrestrial landscapes (Knopf et al. 1988). In British Columbia, about one-half of forest-dwelling terrestrial vertebrate species depend on riparian habitats for breeding (Bunnell et al. 1999). Migratory waterfowls especially require those wetland habitats that support an abundance of invertebrate prey, in order to help them refuel during their long migratory journeys. The relation between wetlands and birds is shaped by many factors but the most important of them is the availability, depth (at least 3 to 5 cm) and quality of water. Drawdowns play a critical role by periodically exposing the sediments and their underlying seed bank and encouraging emergent vegetation growth, which provides food for migratory waterfowls. However, many of these habitats are ephemeral in nature and may not be available during the critical migratory period of numerous birds (from late April to early June in the spring, and from mid-September to late November in the fall).

According to the Migratory Birds Regulations Act of 1994, in Article II Section 1 of the Schedule, no hunting shall occur on migratory game birds between 10 March and 1 September.  According to the Wildlife Act, in Section 34, no person unless exempt by regulation may possess, take, molest, injure, or destroy: a bird or its egg; the nest of an eagle, peregrine falcon, gyrfalcon, osprey, heron or burrowing owl; or the nest of any other bird when it is occupied by the bird or an egg.

Of the pool of priority species that have suitable habitat in the Plan area, the species included in this section were chosen according to the following five guidelines:

1. Is the species at risk or threatened?
2. Is the species an invasive species?
   1. Is this an introduced species that is causing significant damage to the population numbers of indigenous species that are important to ecological balance within the plan area?
3. Is the species of historical or cultural significance?
4. Is the species of economic importance?
   1. Does the presence of this species contribute significantly to the economy of the plan area?
5. Is the species of ecological importance?
   1. Is there significant dependence upon this animal by other species or for the maintenance of ecological balance?

More species will be added to the plan as it evolves. For each species in this section, general issues will be addressed first, followed by issues specific to each species’ population.

Table 1. Species included for management planning and their criteria for selection.

Selected Species	Criteria
Trumpeter Swan	Ecological importance
Canada Goose	Ecological importance
Mallard Duck	Ecological importance
Common Loon	Ecological importance

Issues:

• Water management of the reservoir may be impacting migratory bird populations

Goals:

• Rehabilitate wetland habitat by proposing a plan to improve the management of the water in the reservoir
• Increase the waterfowl food supplies by encouraging invertebrate production by identifying the proper regime of drawdown and flooding to stimulate the growth and decomposition of plants that are a detrital source of food for the invertebrates
• Raise local populations and tourist awareness of the protection of riparian habitat and the importance of water management