Summary of Conesus Lake Fisheries Surveys 2001-2009
As seen in the CLA newsletter, Laker News, Winter 2015 issue, pages 12 and 13.
Warm water fisheries assessments using standard gangs of gill nets were conducted in Conesus Lake in September 2001, 2004, and 2009. The purpose of the surveys was to assess the fish community; the contribution of stocked fingerlings to the walleye population; estimate population characteristics of walleye, smallmouth bass, and northern pike; compare fish community structure to previous surveys; and guide the development of appropriate management recommendations.
Fourteen fish species were sampled in the nets from 1991 to 2009 (see Table 1 in linked Summary). Species dominance shifted from walleye to sunfish, and yellow perch went from being a major component of the fish community in 1991 to a minor component in 1997, to nearly absent in 2004. Brown bullhead became an increasingly larger component of the fish community in the 2000s.
Walleye relative abundance peaked in 1994 and remained high in 1997, but otherwise has been steady at about ten walleye per net from 1991 to 2009 (see Figure 1 in linked Summary). The walleye population during the 2000s had an abundance of larger, older fish in excellent condition. Despite extensive migratory spawning runs in the inlet streams that could be producing fry that potentially recruit to adults, the walleye population is mainly sustained by stocked fingerlings. While they are growing slower than in the 1990s, survival and recruitment of the stocked fingerlings remains good. Slower growth and lower condition could be a sign that the alewife population in Conesus Lake is declining, but no definitive statement regarding the alewife population can be made until further hydroacoustic surveys of the forage community are conducted. Because of discrepancies of scale ages among readers, walleye age and growth analyses for these surveys should be viewed cautiously, and otoliths will be used to age walleye in future surveys. The fishing quality for Conesus Lake walleyes should remain very good for several years.
Smallmouth bass relative abundance peaked in 1994, declined over the next decade, then rebounded in 2009 (see Figure 2 in linked Summary). The smallmouth bass population by 2009 had an abundance of larger, older fish in fair condition. The 2007 and 2006 year classes appear to be strong, but individual fish of these year classes may grow slowly and be in less than desirable condition. The fishing quality for Conesus Lake smallmouths should remain good for several years as the fish from these year classes mature and grow.
Northern pike appear to be moderately abundant (see Figure 3 in linked Summary). The recent maintenance of appropriate lake water levels during early spring have provided adequate flooding of constructed marshes in the Conesus Inlet Wildlife Management Area. This appears to have resulted in successful spawning, fry production, survival, and recruitment of northern pike. Adult pike, while fast growing, are in below average condition in Conesus Lake.
The yellow perch decline in abundance following a late 1970s alewife invasion continued during the 1991-1997 period and remained at this low level from 2001 to 2009 (see Figure 4 in linked Summary). Alewife gill net CPUE varied greatly from 1985 to 2001 and remained at a consistent low level since 2001 (see Figure 4 in linked Summary). While relatively large, yellow perch are in poor condition and alewives are smaller than average and in poor condition.
Rock bass and bluegill relative abundance doubled from 2001 to 2009, while pumpkinseed abundance showed little change (see Figure 5 in linked Summary). Survival and growth appears to be consistent for all three species. Growth was above average for all three species, but condition was poor for rock bass and moderately poor for pumpkinseed and bluegill. Rock bass size structure was poor and few preferred sized pumpkinseeds and bluegills were sampled. Size quality in bluegills declined from 1991-1997 levels.
It is recommended that all current fisheries management actions be continued, 50-day walleye fingerlings be stocked annually over five years, the success of stocked 50-day walleye fingerlings be evaluated, and new objectives be developed in a revised Conesus Lake fisheries management plan.
If you would like to know more about the Conesus Lake fishery and the results of these surveys, a more detailed report is available on the Conesus Lake Association web site at:
Fish Survey Summary
The written assesment can be viewed by clicking the link:
CONESUS LAKE FISH STOCK ASSESSMENTS
Senior Aquatic Biologist
NYSDEC Region 8 Fisheries Unit