Walleye Case Study Case Study: Bois Franc ● Located in Quebec ● Enhancement site is located in a small river run between Baie Booth (upstream) and Baie Ininatik (downstream) ● This stretch has been identified as a historical walleye spawning site by elders within the KFN community. Finding restoration site Remember... ● Walleye that spawn up rivers tend to migrate upstream until they reach some type of impassable barrier (i.e. natural waterfalls or dams) ● The ideal substrate for egg deposition is a coarse rock (cobble)/gravel substrate. ● Presence of an adequate current that will keep incubating substrates clean and well oxygenated, as well as remove toxic metabolites. Bois Franc site ● Baie Booth empties into a small river run approximately 875 m upstream of the proposed site. The river flows straight and wide, altered slightly by a beaver dam approximately 75 m upstream of the culverts ● The rivers flows through the culverts, which are slightly perched, into Baie Ininatik approximately 230 m downstream Existing Conditions Existing Conditions ● The existing substrate consists primarily of sand with embedded cobble ● The area is slightly out of the main current, allowing for well oxygenated conditions and maintenance of a clean substrate Remember... ● Walleye that spawn up rivers tend to migrate upstream until they reach some type of impassable barrier (i.e. natural waterfalls or dams) ● The ideal substrate for egg deposition is a coarse rock (cobble)/gravel substrate. ● Presence of an adequate current that will keep incubating substrates clean and well oxygenated, as well as remove toxic metabolites. Group Activity Determine your restoration objective: ● What are you trying to restore? ● What do the fish need and how can you supply it? ● What if NOTHING is done? What will be done and how? Discuss in your groups: ● List what you plant to do, when and how ● How will you imagine your own impacts to fish habitat? ● How will you monitor success? Site The proposed rehabilitation site: ● Is located immediately downstream of the quadruple culverts along the west bank. ● Is approximately 16 m long x 7 m wide (112 m^2). Recommended Approach to Walleye Habitat Enhancement Technique 1: Substrate enhancement by addition of rock cobble veneer ● Attempt to establish interstitial spaces for successful walleye egg deposition and incubation ● Using clean, angular cobble (64-250 mm), hand-place a 1-2 layer veneer over the existing embedded cobble substrate. ● Over time, increased use of spawning area by adult walleye. Recommended Approach to Walleye Habitat Enhancement Technique 2: Construction of a boulder-cobble spawning site directly at the edge of the main current ● Attempt to build a successful walleye spawning site at the edge of the existing current using boulders and rock cobble ● Building a boulder semi-circle as a submerged current barrier, with cobble substrate placed behind Post-Rehabilitation Monitoring Post-Rehabilitation Monitoring ● Take comparative underwater photos of post- enhancement cobble substrate ● Confirm use by walleye: presence of adults during spawn, eggs on substrate using spotlights during peak spawning times and egg mats on substrate respectively ● Monitor water depth and current during spawning period Brook Trout Case Study The Problem Local fish and game club report that brook trout catch in Depot Creek has dramatically decreased. The club suspects recent flooded conditions and erosion is destroying the habitat. They are willing to raise money and restore habitat to one of their favourite fishing spots Existing Conditions from site visit and drone: Water temperature above 20 C in places (mid-summer) Dissolved oxygen measured at 6 ppm (mid-summer) Electrofishing a known stretch of high quality habitat yield 2 brook trout in 3 passes (low catch) Existing Conditions from site visit and drone: Several morphology Erosion & Sedimentation concerns identified from drone photos Obstructions Existing Conditions from site visit and drone: Several morphology concerns Obstruction identified from drone photos Shallow Pools Existing Conditions from site visit and drone: Several morphology concerns identified from drone photos Sand Deposition & Braided Channel Braided Channel & Sand Deposition Steep Banks – Erosion Obstruction and sand flat Existing Conditions from site visit and drone: Some fast-moving sections with morphology and structure suitable for brook trout Existing Conditions from site visit and drone: Steep, eroding sandy banks in several places – significant continuous input of fine sand into the system Existing Conditions from site visit and drone: Slow-moving, warm flat areas – sandy bottom Underlying gravel-cobble bottom Existing Conditions from site visit and drone: Obstructions from eroding banks, sand deposition in slow-moving areas Existing Conditions from site visit and drone: Braided channels and delta formation Seasonal fish passage concern Existing Conditions from site visit and drone: Alder shrubs overgrown and partially obstructing channel Existing Conditions from site visit and drone: Small, deep pools with minimal cover Restoration Plan for Depot Creek What are the key habitat issues? What techniques can be used in a habitat restoration plan? Restoration Objective What are you trying to restore? What do the fish need and how can you supply it? What if NOTHING is done? What will be done and how? List what you plan to do, when and how How will you mitigate your own impacts to fish habitat? How will you monitor success? Solution Restoration Objective What are you trying to restore? Impaired stream system that has a remnant population of brook trout. Many small habitat issues have had a cumulative effect on brook trout habitat over a long period of time. We are trying to restore habitat conditions that are favourable to brook trout (colder water temperature, deeper and more diverse habitats). Habitat issues need to be individually identified and remediated over time to have a cumulative effect towards restoring the creek system to be once again favourable for brook trout. What do the fish need and how can you supply it? Incremental fish habitat improvements – restoration techniques that will promote increased flow through system, erosion protection to minimize deposition of fine materials (sand) into system, stream deflectors to deflect current/water energy into centre and away from stream banks, fish passage improvements by removing obstructions, structures that can capture bedload migration (sand). What if NOTHING is done? System will continue to degrade in terms of brook trout and coldwater habitat quality. Creek may no longer be able to sustain any cold water fish species, including brook trout. What will be done and how? List what you plan to do, when and how cut back areas where alders have overgrown and are impeding current, remove fallen tree obstructions that are not providing fish habitat, re-purpose alder cuttings by bundling them with wire and using them in combination with re-purposed fallen trees to stabilize eroding banks, re-establish fish passage by replacing undersized road culvert with an appropriately sized culvert that is installed with 10% embedded into stream bed, create a sediment trap with a backhoe to capture migrating sand bedload, create an undercut bank structure in existing small pools for shading and cover, install low-flow deflectors into channel to divert water energy away from banks and in some cases to concentrate flow and scour stream bottom. How will you mitigate your own impacts to fish habitat? Work in water during low flow and when sensitive life stages of cold water (fall-spawning fish) are not present (no in-water work from September 30 to June 15), use hand tools wherever possible, replace culvert by isolating work area and working in-the-dry, install sediment and erosion control measures as applicable. How will you monitor success? Survey anglers, conduct standardized, controlled electrofishing surveys, inspect bank stability, visual inspection and photos of stream morphology. Obstruction Removal – Alder Brush-out Remove obstruction (re-purpose logs for erosion control/stream deflectors). Do not remove in- water logs that may be providing shade/cover Bank Stabilization – Brush Bundles Pool Enhancement – Rootwad installation Channel Deflectors Lake Trout Case Study The Problem Lake trout have apparently stopped spawning on a traditional well-used shoal This shoal is the only known spawning site on the lake Existing Conditions Forest access road built five years ago in remote area adjacent to small lake trout lake (500 ha). The lake trout spawning shoal is almost directly offshore from where the road is located Existing Conditions Little to no vegetated buffer between lake and road Active erosion and sedimentation observed during rain event Existing Conditions Shoal appears to consist of embedded rocks, fine silt-sand and debris. Long time residents recall a rock cobble shoal where one could ‘walk on the lake trout’s backs’ during the fall. Existing Conditions Drainage ditches were built on the other side of the built-up road bed and equalizing culverts were installed to prevent washouts Culverts are typically dry, but are overwhelmed during the spring freshet and flow directly into the lake Restoration Objective What are you trying to restore? What do the fish need and how can you supply it? What if NOTHING is done? What will be done and how? List what you plan to do, when and how How will you mitigate your own impacts to fish habitat? How will you monitor success? Solution Restoration Objective What are you trying to restore? Important lake trout spawning shoal impacted by chronic sedimentation from erosion of newly installed road. What do the fish need and how can you supply it? Clean rock cobble substrate with interstitial spaces for egg deposition. This can be supplied by cleaning the existing shoal and stopping erosion/sedimentation at its source (i.e. the road, the drainage, and the unstable banks What if NOTHING is done? Lake trout population could potentially be lost due to lack of successful spawning; at the very least, a population decline is imminent without intervention.