Owl River Riparian Restoration Project - Progress Report 2012
Tyler Johns and Ariane Cantin
Since 2006, the Government of Alberta has stocked Lac La Biche with nearly 200 million walleye fry in order to restore populations, and many of these walleye are expected to begin spawning within the next few years. The Owl River is identified as the primary spawning habitat for Lac La Biche walleye. However, agricultural activities throughout the area have reduced riparian vegetation and this could potentially increase nutrient and sediment loading of the watercourse. The resulting reduction in water quality can have a direct impact on walleye spawning habitat, thereby potentially limiting the success of the Lac La Biche walleye restoration program.
We collected baseline data on riparian health, water quality, aquatic habitat, and the distribution of walleye spawning habitat, to assess the effectiveness of a long-term initiative to protect and restore riparian vegetation along the Owl River. Our study area extended 40 km upstream from the mouth of the river at Lac La Biche and included a portion of the Piche River. Aerial videography assessment indicated that 47% of the riparian area was in good condition, with 39% and 14% in fair and poor conditions, respectively.
We observed several fish, including walleye and white suckers, in the upstream 10-km section of the study area, but very few fish in the downstream 30-km section. Congregation of walleye in the upstream 10-km section confirms the identification of this section of the river, by Alberta Sustainable Resources Development (ASRD), as suitable walleye spawning grounds. The dominant substrate of sites in the upper section consisted of boulders, cobble and gravel suitable for walleye spawning, while sites in the lower section consisted mainly of fines and sands, not suitable for walleye spawning. Overall, bank disturbance (erosion, exposed soil, human disturbance) along the river was low with grasses, sedges and woody shrubs dominating the vegetation.
Dissolved oxygen was high (6.0-13.1 mg/L) throughout the river system from May to August. Total phosphorus (TP) concentrations were high (summer average: 92-140 μg/L) throughout the system and were the highest at downstream sites. Based on TP values, the Owl River may be considered as eutrophic to hyper-eutrophic. Total nitrogen concentrations ranged from 0.93 to 1.3 mg/L and slightly exceeded the Alberta Environment (AENV) limit (1.0 mg/L) in most cases. Total coliform counts were low in May, but exceeded the CCME limit for agriculture use (>1,000 mpn/100mL) at most sites in the summer. We collected a total of 11,705 macroinvertebrates belonging to 54 families. Diversity ranged from 1.2 to 2.2 and richness ranged from 30 to 36; there were no clear spatial distributional patterns. The most common family was Baetidae (Order: Ephemeroptera).
We initiated communications with several landowners interested in working with Alberta Conservation Association to restore and enhance riparian vegetation along the Owl River. We reached a verbal agreement with a leaseholder, pending approval by ASRD Public Lands, to protect approximately 9 km of riparian area along the river with riparian fencing. We are currently working with ASRD to complete a survey of the new lease boundaries and change the lease permanently.