Biological
Control
Over the past two years biologist George Vardy, of GB Vardy and Associates, has
been surveying and observing existing characteristics of the Haig-Brown Kingfisher Creek
watershed. Now, George and associate Carolyn Heim are developing the biological component
of plans for habitat improvements in the new channel.
The emulation of pre-existing biology in the area is essential to ensuring that the new
stream channel's ecosystem will be self-maintaining after the project's completion. For instance,
vegetation that is not normally found in the area will have less of a chance of thriving, and may
take longer to become establish, if it does at all. These concerns, and a variety of other coho-related habitat considerations must be worked into the plans for the new channel.
The biologists have identified and planned several integral components in the new
channel. One of these is the creation of many pools, ranging from less than a half metre to more
than 2 metres deep. Each of the pools will have cover built-in for salmon habitat, usually some
type of woody debris placed in the pool. These large root wads and logs will provide hiding
places and insect feed for the fish in the system.
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The root wads and logs will be anchored or "keyed" into the banks, inevitably
creating further complex pattern of pools and riffles. The installation of wooden and rock weirs
will also serve to create pools and ideal areas for spawning beds.
Pools and large woody debris provide an excellent source
of shelter and refuge for salmon.
All of this will be done while preserving as much of the existing plant life as possible.
Another key component of the project will be to prevent a loss of water from above
ground into the water table through the existing, naturally sandy, soil. As a solution, a
compacted clay streambed lining will run the length of the new stream channel. It will be
"armored" with cobble and gravel to ensure that it will remain stable, as well as to provide a
good surface for the placement of spawning gravel. After all, without enough clean water and
gravel, returning coho will likely look elsewhere for another creek to spawn in.
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