GMSWORKS-3 Peace River Side Channel Restoration - BC Hydro

the regulated flow regime and a life history strategy that relies heavily on tributary habitats for
critical life requisites such as spawning and early rearing.
There are exceptions to this general observation. Existing side channels and near‐shore areas
along the mainstem channel margins that do not dewater provide habitats for younger fish of
the large‐fish species and small‐fish species. If other basic habitat requirements are met (e.g.,
appropriate water temperatures, water clarity, water velocity, and physical cover) younger fish
of the large‐fish species and small‐fish species can reside within these areas. One example
includes the presence of young rainbow trout, Arctic grayling, slimy sculpin, and prickly sculpin
in near‐shore habitats of the Peace River containing large amounts of physical cover. Another
example is the presence of viable fish populations belonging to the unique species assemblage
relying exclusively on selected side channels to provide all habitat requirements
The Peace River fish community downstream of PCN consists of 31 fish species that can be
divided into three general fish assemblages based on habitat requirements: cold‐clear water
(11 species), cool turbid water (15 species), and unique (5 species).
The cold‐clear water fish assemblage, which consists of salmonid (trout and whitefish) and
cottid (sculpins) species, dominates the mainstem fish community within the study area.
Mountain whitefish, Arctic grayling, bull trout and rainbow trout are the numerically dominant
and most widespread large‐fish species in this assemblage, while slimy sculpin is the most
abundant species in the small‐fish group. Populations in this group are found in side channels
and in near‐shore areas along channel margins in the river mainstem. Small‐fish assemblages
are very flexible in their habitat needs. If appropriate conditions are present, either in side
channels or river mainstem, species in this group would likely utilize these habitats.
The cool‐turbid water fish assemblage consists of a diverse group of large‐fish and small‐fish
species that reside in the river mainstem, but with most of these fish largely restricted to
tributary confluence areas and/or the extreme lower portion of the study area (i.e.,
downstream of the Moberly River confluence). The only exceptions to this pattern are redside
shiners, which are abundant and widely distributed throughout the study area. The restricted
distribution of most cool‐turbid water species is largely due to the requirement for warmer
water temperatures and low water clarity. Populations of goldeye and walleye, for example,
primarily reside downstream of the study area, but will use habitats upstream of the Pine River
confluence opportunistically if appropriate conditions exist (i.e., warm water and high
turbidity). Others such as suckers, northern pikeminnow, and most of the minnow species rely
heavily on tributaries to provide appropriate habitats, and do not venture far from these focal
points. Despite the restricted distribution of most species, side channels are the preferred
habitat when available, but near‐shore areas along channel margins in the river mainstem can
also be utilized.
The unique fish assemblage consists of five species that are almost entirely restricted to side
channels (i.e., lake whitefish, northern pike, yellow perch, white sucker, and spottail shiner). All
occur in a select number of side channels that exhibit specific physical characteristics. The side
Peace River Side Channel Restoration 8