Lesser Slave Lake Walleye Spawning Assessment April – June, 1997
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1997 Lesser Slave Lake Walleye Spawning Assessment Lesser Slave Lake Walleye Spawning Assessment April – June, 1997 Prepared by: Brian Lucko and Glenn Todd October, 1997 Northwest Boreal Region Alberta Conservation Association 1 1997 Lesser Slave Lake Walleye Spawning Assessment Abstract In the spring of 1997, the Alberta Conservation Association conducted a study to confirm the presence of spawning walleye (Stizostedion vitreum) in six tributaries and at four shoreline areas within Lesser Slave Lake in northern Alberta. The six tributaries were the Swan River, Driftpile River, Marten River, Assineau River, Strawberry Creek and Mission Creek. The four shoreline areas include Joussard townsite, Giroux Bay (Faust townsite), Spruce Point Park, and mouth of the Driftpile River. Walleye were captured by electrofishing (primary method) and in some instances, gill netting. When spawning walleye were located, the site was revisited and kick sampling conducted to collect walleye eggs. Thirty kick sampling sites were established during this survey. Electrofishing produced 138 spawning walleye in the lower section of Strawberry Creek. The Driftpile River and Assineau River produced 7 walleye and 1 walleye respectively. No walleye were found in the Swan River and Marten River. A genetic test indicated that walleye eggs were found in Strawberry Creek and at 3 shoreline sites within Lesser Slave Lake: 1) Joussard, 2) Giroux (Faust) Bay, and 3) Spruce Point Park. Alberta Conservation Association 2 1997 Lesser Slave Lake Walleye Spawning Assessment Table of Contents Page 1.0 INTRODUCTION ........................................................................................................................ 1 2.0 STUDY AREA ............................................................................................................................. 2 3.0 METHODS ................................................................................................................................... 4 3.1 Electrofishing and Gill Netting ......................................................................................... 4 3.2 Egg Sampling .................................................................................................................... 4 3.3 DNA Analysis ................................................................................................................... 4 3.4 Mapping of Sample Sites .................................................................................................. 5 4.0 RESULTS AND DISCUSSION ................................................................................................... 7 4.1 Water Temperature ........................................................................................................... 7 4.2 Fish Collection .................................................................................................................. 7 4.2.1 Strawberry Creek ....................................................................................................... 7 4.2.2 Driftpile River ............................................................................................................ 12 4.2.3 Swan River ................................................................................................................. 13 4.2.4 Assineau River ........................................................................................................... 15 4.3 Egg Sampling .................................................................................................................... 16 4.3.1 Strawberry Creek ....................................................................................................... 16 4.3.2 Driftpile River and Swan River ................................................................................. 19 4.3.3 Assineau River, Marten River and Mission Creek .................................................... 19 4.3.4 Lesser Slave Lake ...................................................................................................... 21 4.4 DNA Analysis ................................................................................................................... 23 5.0 RECOMMENDATIONS .............................................................................................................. 24 6.0 LITERATURE CITED ................................................................................................................. 25 Appendix ............................................................................................................................................ 27 ii 1997 Lesser Slave Lake Walleye Spawning Assessment List of Tables Page Table 1. Electrofishing capture results for the Lesser Slave Lake Spawning Assessment. Spring, 1997 ...................................................................................................10 Table 2. Gill netting capture results for the Lesser Slave Lake Spawning Assessment. Spring, 1997 ........................................................................................................................11 Table 3. Egg kick sample sites and results for the Lesser Slave Lake Spawning Assessment. Spring, 1997 ....................................................................................................18 List of Figures Page iii 1997 Lesser Slave Lake Walleye Spawning Assessment Figure 1a. Location of study area within the province of Alberta .....................................................3 Figure 1b. Map of study area showing major tributaries ...................................................................3 Figure 2. Sampling locations in the Lesser Slave Lake Walleye Spawning Assessment study area. Spring, 1997......................................................................................................7 Figure 3. Daily water temperature data from Strawberry Creek, Driftpile River and Swan River. Spring, 1997 ...................................................................................................9 Figure 4. Strawberry Creek (lower section) sampling sites with UTM coordinates. ........................11 Figure 5. Strawberry Creek (upper section) sampling sites with UTM coordinates. .......................12 Figure 6. Driftpile River (lower section) sampling sites with UTM coordinates. ............................13 Figure 7. Driftpile River (upper section) sampling sites with UTM coordinates. .............................13 Figure 8. Swan River (lower section) sampling sites with UTM coordinates. ..................................15 Figure 9. Swan River (middle section) sampling sites with UTM coordinates .................................15 Figure 10. Assineau River sampling sites with UTM coordinates ....................................................17 Figure 11. Marten River sampling sites with UTM coordinates .......................................................20 Figure 12. Joussard and area egg sampling sites with UTM coordinates ..........................................21 Figure 13. Giroux Bay (Faust townsite) egg sampling sites with UTM coordinates ........................22 Figure 14. Spruce Point egg sampling sites with UTM coordinates..................................................22 iv 1997 Lesser Slave Lake Walleye Spawning Assessment 1.0 INTRODUCTION Lesser Slave Lake is rapidly becoming one of the more popular recreational lakes in northern Alberta. As a result, opportunities for the commercial development of shoreline areas are also increasing (Collett and Rhodes 1995). Commercial as well as recreational development around the lake and tributaries can have negative impacts on walleye (Stizostedion vitreum) spawning habitat. Prior to 1995 walleye spawning in Lesser Slave Lake had only been documented on the northwest end of the lake with most walleye concentrating in the South Heart River system (Collett and Rhodes 1995). Traditional walleye spawning grounds are the rocky areas in white water below impassable falls and dams in river, or boulder, to coarse-gravel shoals of lakes (Scott and Crossman, 1973). Studies conducted in the late 70’s and early 80’s ( Dietz, 1979, 1982; Dietz and Tulman, 1981; Berry, 1979, 1981; O’Neil, 1983) indicated that Buffalo Bay and the lower South Heart River are probably the main walleye spawning grounds for Lesser Slave Lake. Hartman (1957) felt that the lower 5 km of the Grouard Channel was the likely spawning ground. However, none of these studies found large aggregations of female walleye. Also, these studies concentrated their efforts on Buffalo Bay and South Heart River. Collett and Rhodes (1995) showed marked use of inshore areas for spawning by walleye. From 1989 to 1993, the spring fishery on the west basin of Lesser Slave Lake averaged 675 kilograms of walleye per year (Alberta Environmental Protection – file data). In 1995, walleye catches during the west basin spring fishery rose dramatically to 3,950 kgs and then to 4,431 kgs in 1996 (file data). The alarming number of pre-spawn walleye, captured during the 1995 and 1996 spring commercial fisheries, prompted the confirmation that walleye are utilizing lakeshore and tributary habitats on Lesser Slave Lake for spawning purposes. Possible reasons why there is an increased use of lakeshore habitats include over utilization of the traditional spawning areas (South Heart River and Grouard Channel) by the expanding walleye population or that the spawning stock has been adversely affected by the large silt loads in the South Heart