Ministry of Natural Resources
Whitefish Lake open-water creel survey: 2008 Scott Parker
Introduction Fishing effort, catch, and harvest information can be used to investigate the effect of fishing on a target fish species as well as support resource management decisions. Information collected during creel surveys, such as angler demographics, are useful when considering the effect of potential regulation changes on both the fish community and anglers. Whitefish Lake is a 3,015 ha waterbody located 60 km southwest of the city of Thunder Bay. The lake has a mean depth of 1.8 m, a maximum depth of 6.4 m, 0.027 mg/L total phosphorus, 66 mg/L total dissolved solids, and a Secchi depth of 1.5 m. The fish of primary importance to anglers in the lake include walleye (Sander vitreus) and yellow perch (Perca flavescens). Northern pike (Esox lucius) and smallmouth bass (Micropterus dolomieu) represent a small proportion of the total angling effort on the lake. Walleye, yellow perch, and smallmouth bass are not native to the lake and were introduced in the 1940s, 1960s, and 1990s respectively (Amtstaetter 2007). Lake whitefish (Coregonus clupeaformis) populations collapsed in the 1950s and never recovered (MacCallum 1983). Several fish regulations have been applied to Whitefish Lake in the past several years because of a concern that the recreational harvest of yellow perch was potentially unsustainable. A reduction in the catch and possession limit of yellow perch, from unlimited to 100 fish in a day, was implemented on Whitefish Lake in 1999. In 2002, the catch limit was again reduced to 50 fish in one day, with a possession limit of 100 for a sport fish licence, and a catch and possession limit of 25 for a conservation licence. A reduction in the catch and possession limit to 50 and 25 for sport and conservation licences respectively was implemented provincewide in 2000. A reduction in the possession limit from 6 to 4 walleye, and a limit of one walleye greater than 46 cm total length (TL), were implemented in 1999. The 1999 walleye regulation changes were not specific to Whitefish Lake, but applied to all waterbodies across Northwest Region. This update documents the results of the 2008 open-water roving creel survey conducted on Whitefish Lake and compares them to results of previous surveys for a better understanding of angler demographics and resource user patterns in the
NWSI Aquatic Update 2011-2
recreational fishery. A review of the status of species targeted by anglers is included to provide context for the creel survey results.
Methods An open-water, stratified roving creel survey was conducted on Whitefish Lake from May 17 to September 07, 2008. The period of sampling occurred from 07:30 to 22:30 and was divided such that 60% of the creel survey was conducted between 07:30–15:00 and 40% was conducted between 15:00–22:30. This was done to reflect historical usage patterns on Whitefish Lake and to closely replicate previous open-water creel surveys. The survey was also stratified by day type (workday or non-workday). There were 75 workdays and 39 non-workdays surveyed. Sample dates were randomly selected for each day type. Angler interviews included questions about each an angler’s or party’s fishing trip, and related socioeconomic information. The following information, collected on standard Ministry of Natural Resource (MNR) creel interview forms, was recorded during the survey: date, interview time, fishing start time, number of anglers, fishing method (still, jig, drift, troll, combination/other), angler origin, accommodation type, species sought, whether a guide was employed, and the number of each species harvested and released. The following questions were also asked about each party’s fishing trip: how many walleye greater than 46 cm (18 inches) were harvested; how many walleye greater than 46 cm (18 inches) were released; how many anglers had a conservation fishing licence; did you stop fishing at any time and for how long; and did you have a shore lunch? Each day, fish were sampled during the angler interviews at the commercial resorts between 11:30– 12:30 and 20:30–22:30. Fish were measured for length (mm) and weight (g), and structures for age assessment were collected. Effort, catch, and harvest estimates for creel survey data were generated using FISHNET v2.0 (Lester and Korver 1996). The total harvest weight of each species was estimated by summing the products of estimated harvest and mean weight of sampled fish. The number of walleye that were released due to compliance with fishery regulations was determined from observed values.