The Oneida Lake Creel Survey, 2002-2007
Angling on Oneida Lake is a popular activity and represents a large economic stimulus to the surrounding area. Despite over 50 years of fish population and limnological monitoring by Cornell University Biological Field Station, assessments of the impact of angling on sportfish populations in the lake are limited. Angling effort and success was assessed in the late 1950s (Grosslein 1961) and in 1997-1998 (VanDeValk et al. 1999). Through funding from the New York State Department of Environmental Conservation, a creel survey, based on the methods used by Grosslein (1961), was conducted during the 2002-2007 walleye angling seasons.
The season was separated into 2 time periods, open water, early May until late October, and ice, late January until mid-March. Angling effort was estimated by counting boats from a 10m tower and adjusting those counts based on a relationship between tower counts and concurrent flyovers. Counts were then multiplied by the number of hours of daylight, for that day, to estimate angling effort in boat hours. Estimates of total effort are presented in angler-hours which are calculated by multiplying the number of boats counted by the mean number of anglers per boat during the sample period.
Angler success was estimated from roving (on lake) interviews of anglers while they fished. Angler success rate data was recorded by the clerk and included: how long the party had been fishing, how many anglers were in the party, how many fish were caught, by species, and how many fish were harvested, by species. Individual catch or harvest rates were calculated by dividing the number of fish caught or harvested by the individual party's effort (duration of trip times the number of anglers). Mean success rates were then averaged over the time period reported (day, month or season). Estimates of total catch and harvest are the product of angling effort (boat-hours) times angler success.
During 2 of the roving survey years, usable concurrent access point surveys were conducted by interns during summer months (mid June through early July 2002 and 2006). Methods comparisons of roving and access point (boat launch) interviews were conducted to identify if those methods were interchangeable.
Angler effort generally increased throughout the survey from 12.95 angler-hours/ha (2002) to 22.3 angler-hours/ha (2007). Most of the angling effort occurred during the open water season (mean: 84%) and ranged from 9.35 angler-hours/ha (2002) to 18.02 (2006). The majority of interviewed anglers, during the open water season, reported targeting walleye (mean: 68%). Black bass were targeted by 17% of anglers and yellow perch by 14%. Ice season effort ranged from a low during the 2005 walleye season of 0.34 angler-hours/ha, a result of incomplete and inconsistent ice cover, to 4.4 angler-hours/ha during the 2007 season. Anglers reported fishing for walleye and yellow perch (56%) more often that each species individually (walleye: 18%; yellow perch 0.19).
Annually, anglers caught a mean of 0.23 walleye/angler-h, 0.41 yellow perch/angler-h, and 0.19 black bass/angler-h. Catch rates of walleye during the open water season increased from 2002-2004 (0.23 - 0.63 fish/angler-h) and declined to a mean of 0.2 walleye/angler-h during 2005-2007. Yellow perch catch rates declined from 2002 through 2005 (range: 0.44 - 0.07 fish/angler-h) and increased in 2006 (0.58 fish/angler-h) and 2007 (0.52 fish/angler-h). Black bass catch rates were relatively consistent, ranging from 0.15 to 0.24 fish/angler-h.
Ice angling catch rates were variable for both walleye and yellow perch. Anglers caught a mean of 0.15 walleye/angler-h (range: 0.05 - 0.26 walleye/angler-h). Yellow perch catch rates ranged from 0.03 to 1.0 fish/angler-h (mean: 0.49 fish/angler-h).
Annual mean harvest rates were 0.09 walleye/angler-h, 0.29 yellow perch/angler-h, and 0.03 black bass/angler-h. Open water walleye harvest rates increased from 2002 to 2004 (0.04 to 0.14 fish/angler-h) and remained relatively consistent for the duration of the survey. In October of 2004, the minimum length limit for walleye was changed from 18 inches to 15 inches. Yellow perch open water harvest rates trended similarly to yellow perch catch rates (range: 0.05-0.39 fish/angler-h). Black bass open water harvest rates were low (range: 0.008 - 0.04 fish/angler-h), which may reflect a preference for catch and release by bass anglers.
Total harvest was 224,700 walleyes, 389,000 yellow perch, and 41,200 black bass. Mean angling mortality was estimated as 7% (range: 2 - 12%) for walleye and 5% (range: 0.9 - 10%) for yellow perch.
Comparisons of angler success rates estimated from roving and access point surveys indicated that there were no significant differences between harvest rates for either year and for catch rates in 2006. However, in 2002 there were significant differences between walleye (p = 0.0002) and yellow perch (p = 0.04).
Catch and harvest rates of walleyes and yellow perch were compared to the number of cormorant feeding days during the study period. These comparisons suggested a significant negative linear relationship with cormorant feeding days only, which is likely a result of the 2004 regulation change rather than an indication of direct negative impacts of cormorants on angler catch rates.
(The complete report is available as a PDF in the right hand column)