Otisco Lake Fall Walleye Survey (2013)
Survey Number: 713028
Survey Date: October 2, 2013
Fall night electrofishing was conducted along 3.7 miles of the Otisco Lake shoreline to determine the relative success of the 2013 stocking of 44,000 50-day walleye fingerlings. First year survival of the stocked walleye is assessed by night electrofishing in the fall. In 2013, 94 Young-of-Year (YOY) walleye were captured along with 18 older (up to age 8) walleye. Length of the older walleye ranged from 12.1 to 22.7 inches. The YOY walleye showed good growth rates with an average length of 7 inches and all were caught south of the causeway, where the majority of the stocked walleye have been planted since 2002. Of the 44,000 stocked in June 2013, approximately 33,000 were stocked south of the causeway and 11,000 north of the causeway.
Using Serns' 1982 formula for estimating numbers of YOY walleye provides a population estimate of 3,908 in the south end of the lake below the causeway. If accurate, this estimate represents a 12% survival rate (based on the 33,000 stocked south of the causeway). The 12% estimated survival rate is the highest yet during this five year experiment at Otisco Lake. Previous survival estimates for 50-day walleye in Otisco range from 0.05 to 3% but it should be noted that our ability to sample was hampered by mechanical issues during 2009 and 2011, and by extremely low water levels in 2012. For perspective, the broad range of survival for these 50-day walleye is similar to what we observed previously from stocked "pond fingerling" walleyes. Further evaluation of the 50-day walleye stocking experiment for Otisco Lake will be undertaken during the summer and fall of 2014.
Gamefish were the target species and in addition to walleye, 16 tiger musky (8.3-31.2 inches), 37 smallmouth bass (6.2-17.3 inches), 29 largemouth bass (5.3-16.9 inches), and one brown trout (15.7 inches) were also collected.